#-------------------------------------------------------------------------
# Copyright (c) Microsoft. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#--------------------------------------------------------------------------
require 'azure/service/storage_service'
require 'azure/blob/serialization'
require 'base64'

module Azure
  module Blob
    class BlobService < Service::StorageService

      def initialize
        super()
        @host = Azure.config.storage_blob_host
      end

      # Public: Get a list of Containers from the server
      #
      # ==== Attributes
      #
      # * +options+       - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:prefix+       - String. Filters the results to return only containers 
      #   whose name begins with the specified prefix. (optional)
      #
      # * +:marker+       - String. An identifier the specifies the portion of the 
      #   list to be returned. This value comes from the property
      #   Azure::Service::EnumerationResults.continuation_token when there 
      #   are more containers available than were returned. The 
      #   marker value may then be used here to request the next set
      #   of list items. (optional)
      #
      # * +:max_results+  - Integer. Specifies the maximum number of containers to return. 
      #   If max_results is not specified, or is a value greater than 
      #   5,000, the server will return up to 5,000 items. If it is set 
      #   to a value less than or equal to zero, the server will return 
      #   status code 400 (Bad Request). (optional)
      #
      # * +:metadata+     - Boolean. Specifies whether or not to return the container metadata.
      #   (optional, Default=false)
      #
      # * +:timeout+      - Integer. A timeout in seconds.
      #
      # NOTE: Metadata requested with the :metadata parameter must have been stored in
      # accordance with the naming restrictions imposed by the 2009-09-19 version of the Blob 
      # service. Beginning with that version, all metadata names must adhere to the naming 
      # conventions for C# identifiers.
      #
      # See: http://msdn.microsoft.com/en-us/library/aa664670(VS.71).aspx 
      #
      # Any metadata with invalid names which were previously stored, will be returned with the 
      # key "x-ms-invalid-name" in the metadata hash. This may contain multiple values and be an
      # Array (vs a String if it only contains a single value).
      # 
      # Returns an Azure::Service::EnumerationResults
      def list_containers(options={})
        query = { }
        if options
          query["prefix"] = options[:prefix] if options[:prefix]
          query["marker"] = options[:marker] if options[:marker]
          query["maxresults"] = options[:max_results].to_s if options[:max_results]
          query["include"] = "metadata" if options[:metadata] == true
          query["timeout"] = options[:timeout].to_s if options[:timeout]
        end
        
        uri = containers_uri(query)
        response = call(:get, uri)

        Serialization.container_enumeration_results_from_xml(response.body)
      end

      # Public: Create a new container 
      #
      # ==== Attributes
      #
      # * +name+          - String. The name of the container
      # * +options+       - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:metadata+            - Hash. User defined metadata for the container (optional)
      # * +:public_access_level+ - String. One of "container" or "blob" (optional)
      # * +:timeout+             - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179468.aspx
      #
      # Returns a Container
      def create_container(name, options={})
        query = { }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = container_uri(name, query)

        headers = { }

        add_metadata_to_headers(options[:metadata], headers) if options[:metadata]

        headers["x-ms-blob-public-access"] = options[:public_access_level].to_s if options[:public_access_level]

        response = call(:put, uri, nil, headers)

        container = Serialization.container_from_headers(response.headers)
        container.name = name
        container.metadata = options[:metadata]
        container
      end

      # Public: Deletes a container
      #
      # ==== Attributes
      #
      # * +name+       - String. The name of the container
      # * +options+    - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:timeout+   - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179408.aspx
      #
      # Returns nil on success
      def delete_container(name, options={})
        query = { }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        call(:delete, container_uri(name, query))
        nil
      end

      # Public: Returns all properties and metadata on the container.
      #
      # ==== Attributes
      #
      # * +name+       - String. The name of the container
      # * +options+    - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:timeout+   - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179370.aspx
      #
      # Returns a Container
      def get_container_properties(name, options={})
        query = { }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        response = call(:get, container_uri(name, query))

        container = Serialization.container_from_headers(response.headers)
        container.name = name
        container
      end

      # Public: Returns only user-defined metadata for the specified container.
      #
      # ==== Attributes
      #
      # * +name+       - String. The name of the container
      # * +options+    - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:timeout+   - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691976.aspx
      #
      # Returns a Container
      def get_container_metadata(name, options={})
        query = { "comp" => "metadata" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        response = call(:get, container_uri(name, query))

        container = Serialization.container_from_headers(response.headers)
        container.name = name
        container
      end

      # Public: Gets the access control list (ACL) and any container-level access policies 
      # for the container.
      #
      # ==== Attributes
      #
      # * +name+       - String. The name of the container
      # * +options+    - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:timeout+   - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179469.aspx
      #
      # Returns a tuple of (container, signed_identifiers)
      #   container           - A Azure::Entity::Blob::Container instance
      #   signed_identifiers  - A list of Azure::Entity::SignedIdentifier instances
      #
      def get_container_acl(name, options={})
        query = { "comp" => "acl" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]
        response = call(:get, container_uri(name, query))

        container = Serialization.container_from_headers(response.headers)
        container.name = name

        signed_identifiers = nil
        signed_identifiers = Serialization.signed_identifiers_from_xml(response.body) if response.body != nil && response.body.length > 0

        return container, signed_identifiers
      end

      # Public: Sets the ACL and any container-level access policies for the container.
      #
      # ==== Attributes
      #
      # * +name+                         - String. The name of the container
      # * +public_access_level+          - String. The container public access level
      # * +options+                      - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:signed_identifiers+          - Array. A list of Azure::Entity::SignedIdentifier instances (optional) 
      # * +:timeout+                     - Integer. A timeout in seconds.
      # 
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179391.aspx
      #
      # Returns a tuple of (container, signed_identifiers)
      # * +container+           - A Azure::Entity::Blob::Container instance
      # * +signed_identifiers+  - A list of Azure::Entity::SignedIdentifier instances
      #
      def set_container_acl(name, public_access_level, options={})
        query = { "comp" => "acl" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]
        uri =container_uri(name, query)

        headers = { }
        headers["x-ms-blob-public-access"] = public_access_level if public_access_level && public_access_level.to_s.length > 0

        signed_identifiers = nil
        signed_identifiers = options[:signed_identifiers] if options[:signed_identifiers]

        body = nil
        body = Serialization.signed_identifiers_to_xml(signed_identifiers) if signed_identifiers && headers["x-ms-blob-public-access"] == "container"

        response = call(:put, uri, body, headers)

        container = Serialization.container_from_headers(response.headers)
        container.name = name
        container.public_access_level = public_access_level

        return container, signed_identifiers || []

      end

      # Public: Sets custom metadata for the container.
      #
      # ==== Attributes
      #
      # * +name+      - String. The name of the container
      # * +metadata+  - Hash. A Hash of the metadata values
      # * +options+   - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:timeout+  - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179362.aspx
      #
      # Returns nil on success
      def set_container_metadata(name, metadata, options={})
        query = { "comp" => "metadata" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        headers = { }
        add_metadata_to_headers(metadata, headers) if metadata

        call(:put, container_uri(name, query), nil, headers)
        nil
      end

      # Public: Get a list of Blobs from the server
      #
      # ==== Attributes
      #
      # * +name+              - String. The name of the container to list blobs for. 
      # * +options+           - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:prefix+           - String. Filters the results to return only blobs 
      #   whose name begins with the specified prefix. (optional)
      # * +:delimiter+        - String. When the request includes this parameter, the operation 
      #   returns a BlobPrefix element in the response body that acts as a 
      #   placeholder for all blobs whose names begin with the same substring 
      #   up to the appearance of the delimiter character. The delimiter may 
      #   be a single character or a string.
      # * +:marker+           - String. An identifier that specifies the portion of the 
      #   list to be returned. This value comes from the property
      #   Azure::Service::EnumerationResults.continuation_token when 
      #   there are more blobs available than were returned. The 
      #   marker value may then be used here to request the next set
      #   of list items. (optional)
      # * +:max_results+      - Integer. Specifies the maximum number of blobs to return. 
      #   If max_results is not specified, or is a value greater than 
      #   5,000, the server will return up to 5,000 items. If it is set 
      #   to a value less than or equal to zero, the server will return 
      #   status code 400 (Bad Request). (optional)
      # * +:metadata+         - Boolean. Specifies whether or not to return the blob metadata.
      #   (optional, Default=false)
      # * +:snapshots+        - Boolean. Specifies that snapshots should be included in the 
      #   enumeration. Snapshots are listed from oldest to newest in the 
      #   response. (optional, Default=false)
      # * +:uncomittedblobs+  - Boolean. Specifies that blobs for which blocks have been uploaded, 
      #   but which have not been committed using put_block_list, be included
      #   in the response. (optional, Default=false)
      # * +:copy+             - Boolean. Specifies that metadata related to any current or previous 
      #   copy_blob operation should be included in the response. 
      #   (optional, Default=false)
      # * +:timeout+          - Integer. A timeout in seconds.
      #
      # NOTE: Metadata requested with the :metadata parameter must have been stored in
      # accordance with the naming restrictions imposed by the 2009-09-19 version of the Blob 
      # service. Beginning with that version, all metadata names must adhere to the naming 
      # conventions for C# identifiers.
      #
      # See: http://msdn.microsoft.com/en-us/library/windowsazure/dd135734.aspx
      #
      # Any metadata with invalid names which were previously stored, will be returned with the 
      # key "x-ms-invalid-name" in the metadata hash. This may contain multiple values and be an
      # Array (vs a String if it only contains a single value).
      # 
      # Returns an Azure::Service::EnumerationResults
      def list_blobs(name, options={})
        query = { "comp" => "list" }
        query["prefix"] = options[:prefix].gsub(/\\/, "/") if options[:prefix]
        query["delimiter"] = options[:delimiter] if options[:delimiter]
        query["marker"] = options[:marker] if options[:marker]
        query["maxresults"] = options[:max_results].to_s if options[:max_results]
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        included_datasets = []
        included_datasets.push("metadata") if options[:metadata] == true
        included_datasets.push("snapshots") if options[:snapshots] == true
        included_datasets.push("uncommittedblobs") if options[:uncommittedblobs] == true
        included_datasets.push("copy") if options[:copy] == true

        query["include"] = included_datasets.join ',' if included_datasets.length > 0

        uri = container_uri(name, query)
        response = call(:get, uri)

        Serialization.blob_enumeration_results_from_xml(response.body)
      end

      # Public: Creates a new page blob. Note that calling create_page_blob to create a page
      # blob only initializes the blob. To add content to a page blob, call create_blob_pages method.
      # 
      # ==== Attributes
      #
      # * +container+ - String. The container name.
      # * +blob+      - String. The blob name.
      # * +length+    - Integer. Specifies the maximum size for the page blob, up to 1 TB. The page blob size must be aligned to a 512-byte boundary.
      # * +options+   - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:content_type+          - String. Content type for the request. Will be saved with blob unless alternate value is provided in blob_content_type.
      # * +:content_encoding+      - String. Content encoding for the request. Will be saved with blob unless alternate value is provided in blob_content_encoding.
      # * +:content_language+      - String. Content language for the request. Will be saved with blob unless alternate value is provided in blob_content_language.
      # * +:content_md5+           - String. Content MD5 for the request. Will be saved with blob unless alternate value is provided in blob_content_md5.
      # * +:cache_control+         - String. Cache control for the request. Will be saved with blob unless alternate value is provided in blob_cache_control.
      # * +:blob_content_type+     - String. Content type for the blob. Will be saved with blob.
      # * +:blob_content_encoding+ - String. Content encoding for the blob. Will be saved with blob.
      # * +:blob_content_language+ - String. Content language for the blob. Will be saved with blob.
      # * +:blob_content_md5+      - String. Content MD5 for the blob. Will be saved with blob.
      # * +:blob_cache_control+    - String. Cache control for the blob. Will be saved with blob.
      # * +:metadata+              - Hash. Custom metadata values to store with the blob.
      # * +:sequence_number+       - Integer. The sequence number is a user-controlled value that you can use to track requests. The value of the sequence number must be between 0 and 2^63 - 1.The default value is 0.
      # * +:timeout+               - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179451.aspx
      #
      # Returns a Blob
      def create_page_blob(container, blob, length, options={})
        query = { }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        headers = { }

        # set x-ms-blob-type to PageBlob
        headers["x-ms-blob-type"] = "PageBlob"

        # ensure content-length is 0 and x-ms-blob-content-length is the blob length
        headers["Content-Length"] = 0.to_s
        headers["x-ms-blob-content-length"] = length.to_s
        
        # set x-ms-sequence-number from options (or default to 0)
        headers["x-ms-sequence-number"] = (options[:sequence_number] || 0).to_s

        # set the rest of the optional headers
        headers["Content-Type"] = options[:content_type] if options[:content_type]
        headers["Content-Encoding"] = options[:content_encoding] if options[:content_encoding]
        headers["Content-Language"] = options[:content_language] if options[:content_language]
        headers["Content-MD5"] = options[:content_md5] if options[:content_md5]
        headers["Cache-Control"] = options[:cache_control] if options[:cache_control]

        headers["x-ms-blob-content-type"] = options[:blob_content_type] if options[:blob_content_type]
        headers["x-ms-blob-content-encoding"] = options[:blob_content_encoding] if options[:blob_content_encoding]
        headers["x-ms-blob-content-language"] = options[:blob_content_language] if options[:blob_content_language]
        headers["x-ms-blob-content-md5"] = options[:blob_content_md5] if options[:blob_content_md5]
        headers["x-ms-blob-cache-control"] = options[:blob_cache_control] if options[:blob_cache_control]

        add_metadata_to_headers(options[:metadata], headers) if options[:metadata]

        # call PutBlob with empty body
        response = call(:put, uri, nil, headers)

        result = Serialization.blob_from_headers(response.headers)
        result.name = blob

        result
      end

      # Public: Creates a range of pages in a page blob.
      #
      # ==== Attributes
      #
      # * +container+    - String. Name of container
      # * +blob+         - String. Name of blob
      # * +start_range+  - Integer. Position of first byte of first page
      # * +end_range+    - Integer. Position of last byte of of last page
      # * +content+      - IO or String. Content to write. Length in bytes should equal end_range - start_range
      # * +options+      - Hash. A collection of options.
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:if_sequence_number_lte+ - If the blob's sequence number is less than or equal to the specified value, the request proceeds; otherwise it fails with the SequenceNumberConditionNotMet error (HTTP status code 412 - Precondition Failed).
      # * +:if_sequence_number_lt+  - If the blob's sequence number is less than the specified value, the request proceeds; otherwise it fails with SequenceNumberConditionNotMet error (HTTP status code 412 - Precondition Failed).
      # * +:if_sequence_number_eq+  - If the blob's sequence number is equal to the specified value, the request proceeds; otherwise it fails with SequenceNumberConditionNotMet error (HTTP status code 412 - Precondition Failed).
      # * +:if_modified_since+      - A DateTime value. Specify this conditional header to write the page only if the blob has been modified since the specified date/time. If the blob has not been modified, the Blob service returns status code 412 (Precondition Failed).
      # * +:if_unmodified_since+    - A DateTime value. Specify this conditional header to write the page only if the blob has not been modified since the specified date/time. If the blob has been modified, the Blob service returns status code 412 (Precondition Failed).
      # * +:if_match+               - An ETag value. Specify an ETag value for this conditional header to write the page only if the blob's ETag value matches the value specified. If the values do not match, the Blob service returns status code 412 (Precondition Failed).
      # * +:if_none_match+          - An ETag value. Specify an ETag value for this conditional header to write the page only if the blob's ETag value does not match the value specified. If the values are identical, the Blob service returns status code 412 (Precondition Failed).
      # * +:timeout+                - Integer. A timeout in seconds.
      # 
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691975.aspx
      #
      # Returns Blob
      def create_blob_pages(container, blob, start_range, end_range, content, options={})
        query = { "comp" => "page" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)
        headers = { }
        headers["x-ms-range"] = "bytes=#{start_range}-#{end_range}"
        headers["x-ms-page-write"] = "update"

        # clear default content type
        headers["Content-Type"] = ""

        # set optional headers
        unless options.empty?
          headers["x-ms-if-sequence-number-lte"] = options[:if_sequence_number_lte] if options[:if_sequence_number_lte]
          headers["x-ms-if-sequence-number-lt"] = options[:if_sequence_number_lt] if options[:if_sequence_number_lt]
          headers["x-ms-if-sequence-number-eq"] = options[:if_sequence_number_eq] if options[:if_sequence_number_eq]
          headers["If-Modified-Since"] = options[:if_modified_since] if options[:if_modified_since]
          headers["If-Unmodified-Since"] = options[:if_unmodified_since] if options[:if_unmodified_since]
          headers["If-Match"] = options[:if_match] if options[:if_match]
          headers["If-None-Match"] = options[:if_none_match] if options[:if_none_match]
        end

        response = call(:put, uri, content, headers)

        result = Serialization.blob_from_headers(response.headers)
        result.name = blob

        result
      end

      # Public: Clears a range of pages from the blob.
      #
      # ==== Attributes
      #
      # * +container+    - String. Name of container.
      # * +blob+         - String. Name of blob.
      # * +start_range+  - Integer. Position of first byte of first page.
      # * +end_range+    - Integer. Position of last byte of of last page.
      # * +options+      - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:timeout+     - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691975.aspx
      #
      # Returns Blob
      def clear_blob_pages(container, blob, start_range, end_range, options={})
        query = { "comp" => "page" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        headers = { }
        headers["x-ms-range"] = "bytes=#{start_range}-#{end_range}"
        headers["x-ms-page-write"] = "clear"

        # clear default content type
        headers["Content-Type"] = ""

        response = call(:put, uri, nil, headers)

        result = Serialization.blob_from_headers(response.headers)
        result.name = blob

        result
      end

      # Public: Creates a new block blob or updates the content of an existing block blob.
      # 
      # Updating an existing block blob overwrites any existing metadata on the blob
      # Partial updates are not supported with create_block_blob the content of the
      # existing blob is overwritten with the content of the new blob. To perform a
      # partial update of the content of a block blob, use the create_block_list
      # method.
      #
      # Note that the default content type is application/octet-stream.
      #
      # ==== Attributes
      #
      # * +container+   - String. The container name.
      # * +blob+        - String. The blob name.
      # * +content+     - IO or String. The content of the blob.
      # * +options+      - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:content_type+          - String. Content type for the request. Will be saved with blob unless alternate value is provided in blob_content_type.
      # * +:content_encoding+      - String. Content encoding for the request. Will be saved with blob unless alternate value is provided in blob_content_encoding.
      # * +:content_language+      - String. Content language for the request. Will be saved with blob unless alternate value is provided in blob_content_language.
      # * +:content_md5+           - String. Content MD5 for the request. Will be saved with blob unless alternate value is provided in blob_content_md5.
      # * +:cache_control+         - String. Cache control for the request. Will be saved with blob unless alternate value is provided in blob_cache_control.
      # * +:blob_content_type+     - String. Content type for the blob. Will be saved with blob.
      # * +:blob_content_encoding+ - String. Content encoding for the blob. Will be saved with blob.
      # * +:blob_content_language+ - String. Content language for the blob. Will be saved with blob.
      # * +:blob_content_md5+      - String. Content MD5 for the blob. Will be saved with blob.
      # * +:blob_cache_control+    - String. Cache control for the blob. Will be saved with blob.
      # * +:metadata+              - Hash. Custom metadata values to store with the blob.
      # * +:timeout+               - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179451.aspx
      #
      # Returns a Blob
      def create_block_blob(container, blob, content, options={})
        query = { }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)
        
        headers = { }

        # set x-ms-blob-type to BlockBlob
        headers["x-ms-blob-type"] = "BlockBlob"

        # set the rest of the optional headers
        headers["Content-Type"] = options[:content_type] || "application/octet-stream"
        headers["Content-Encoding"] = options[:content_encoding] if options[:content_encoding]
        headers["Content-Language"] = options[:content_language] if options[:content_language]
        headers["Content-MD5"] = options[:content_md5] if options[:content_md5]
        headers["Cache-Control"] = options[:cache_control] if options[:cache_control]

        headers["x-ms-blob-content-type"] = options[:blob_content_type] if options[:blob_content_type]
        headers["x-ms-blob-content-encoding"] = options[:blob_content_encoding] if options[:blob_content_encoding]
        headers["x-ms-blob-content-language"] = options[:blob_content_language] if options[:blob_content_language]
        headers["x-ms-blob-content-md5"] = options[:blob_content_md5] if options[:blob_content_md5]
        headers["x-ms-blob-cache-control"] = options[:blob_cache_control] if options[:blob_cache_control]

        add_metadata_to_headers(options[:metadata], headers) if options[:metadata]

        # call PutBlob with empty body
        response = call(:put, uri, content, headers)

        result = Serialization.blob_from_headers(response.headers)
        result.name = blob

        result
      end

      # Public: Creates a new block to be committed as part of a block blob.
      #
      # ==== Attributes
      #
      # * +container+   - String. The container name.
      # * +blob+        - String. The blob name.
      # * +block_id+    - String. The block id. Note: this should be the raw block id, not Base64 encoded.
      # * +content+     - IO or String. The content of the blob.
      # * +options+      - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:content_md5+           - String. Content MD5 for the request contents.
      # * +:timeout+               - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd135726.aspx
      #
      # Returns the MD5 of the uploaded block (as calculated by the server)
      def create_blob_block(container, blob, block_id, content, options={})
        query = { "comp" => "block" }
        query["blockid"] = Base64.strict_encode64(block_id)
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        headers = { }
        headers["Content-MD5"] = options[:content_md5] if options[:content_md5]

        response = call(:put, uri, content, headers)

        response.headers["Content-MD5"]
      end

      # Public: Commits existing blob blocks to a blob.
      #  
      # This method writes a blob by specifying the list of block IDs that make up the
      # blob. In order to be written as part of a blob, a block must have been 
      # successfully written to the server in a prior create_blob_block method.
      # 
      # You can call Put Block List to update a blob by uploading only those blocks 
      # that have changed, then committing the new and existing blocks together. 
      # You can do this by specifying whether to commit a block from the committed 
      # block list or from the uncommitted block list, or to commit the most recently
      # uploaded version of the block, whichever list it may belong to.
      # 
      # ==== Attributes
      #
      # * +container+   - String. The container name.
      # * +blob+        - String. The blob name.
      # * +block_list+  - Array. A ordered list of lists in the following format: 
      #   [ ["block_id1", :committed], ["block_id2", :uncommitted], ["block_id3"], ["block_id4", :committed]... ]
      #   The first element of the inner list is the block_id, the second is optional 
      #   and can be either :committed or :uncommitted to indicate in which group of blocks 
      #   the id should be looked for. If it is omitted, the latest of either group will be used.
      # * +options+     - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:content_md5+           - String. Content MD5 for the request contents (not the blob contents!)
      # * +:blob_content_type+     - String. Content type for the blob. Will be saved with blob.
      # * +:blob_content_encoding+ - String. Content encoding for the blob. Will be saved with blob.
      # * +:blob_content_language+ - String. Content language for the blob. Will be saved with blob.
      # * +:blob_content_md5+      - String. Content MD5 for the blob. Will be saved with blob.
      # * +:blob_cache_control+    - String. Cache control for the blob. Will be saved with blob.
      # * +:metadata+              - Hash. Custom metadata values to store with the blob.
      # * +:timeout+               - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179467.aspx 
      # 
      # Returns nil on success
      def commit_blob_blocks(container, blob, block_list, options={})
        query = { "comp" => "blocklist" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        headers = { }
        unless options.empty?
          headers["Content-MD5"] = options[:content_md5] if options[:content_md5]
          headers["x-ms-blob-content-type"] = options[:blob_content_type] if options[:blob_content_type]
          headers["x-ms-blob-content-encoding"] = options[:blob_content_encoding] if options[:blob_content_encoding]
          headers["x-ms-blob-content-language"] = options[:blob_content_language] if options[:blob_content_language]
          headers["x-ms-blob-content-md5"] = options[:blob_content_md5] if options[:blob_content_md5]
          headers["x-ms-blob-cache-control"] = options[:blob_cache_control] if options[:blob_cache_control]

          add_metadata_to_headers(options[:metadata], headers) if options[:metadata]
        end

        body = Serialization.block_list_to_xml(block_list)
        call(:put, uri, body, headers)
        nil
      end

      # Public: Retrieves the list of blocks that have been uploaded as part of a block blob.
      # 
      # There are two block lists maintained for a blob:
      # 1) Committed Block List: The list of blocks that have been successfully 
      #    committed to a given blob with commitBlobBlocks.
      # 2) Uncommitted Block List: The list of blocks that have been uploaded for a 
      #    blob using Put Block (REST API), but that have not yet been committed. 
      #    These blocks are stored in Windows Azure in association with a blob, but do
      #    not yet form part of the blob.
      #
      # ==== Attributes
      #
      # * +container+       - String. The container name.
      # * +blob+            - String. The blob name.
      # * +options+         - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:blocklist_type+ - Symbol. One of :all, :committed, :uncommitted. Defaults to :all (optional)
      # * +:snapshot+       - String. An opaque DateTime value that specifies the blob snapshot to 
      #   retrieve information from. (optional)
      # * +:timeout+        - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179400.aspx
      #
      # Returns a list of Azure::Entity::Blob::Block instances
      def list_blob_blocks(container, blob, options={})

        options[:blocklist_type] = options[:blocklist_type] || :all

        query = { "comp" => "blocklist" }
        query["snapshot"] = options[:snapshot] if options[:snapshot]
        query["blocklisttype"] = options[:blocklist_type].to_s if options[:blocklist_type]
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        response = call(:get, uri)

        Serialization.block_list_from_xml(response.body)
      end

      # Public: Returns all properties and metadata on the blob.
      #
      # ==== Attributes
      #
      # * +container+      - String. The container name.
      # * +blob+           - String. The blob name.
      # * +options+        - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:snapshot+      - String. An opaque DateTime value that specifies the blob snapshot to 
      #   retrieve information from.
      # * +:timeout+       - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179394.aspx
      #
      # Returns a Blob
      def get_blob_properties(container, blob, options={})
        query = { }
        query["snapshot"] = options[:snapshot] if options[:snapshot]
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        response = call(:get, uri)

        result = Serialization.blob_from_headers(response.headers)

        result.name = blob
        result.snapshot = options[:snapshot]

        result
      end

      # Public: Returns metadata on the blob.
      #
      # ==== Attributes
      #
      # * +container+      - String. The container name.
      # * +blob+           - String. The blob name.
      # * +options+        - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:snapshot+      - String. An opaque DateTime value that specifies the blob snapshot to 
      #   retrieve information from.
      # * +:timeout+       - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179350.aspx
      #
      # Returns a Blob
      def get_blob_metadata(container, blob, options={})
        query = {"comp"=>"metadata"}
        query["snapshot"] = options[:snapshot] if options[:snapshot]
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        response = call(:get, uri)

        result = Serialization.blob_from_headers(response.headers)

        result.name = blob
        result.snapshot = options[:snapshot]

        result
      end

      # Public: Returns a list of active page ranges for a page blob. Active page ranges are 
      # those that have been populated with data.
      #
      # ==== Attributes
      #
      # * +container+       - String. The container name.
      # * +blob+            - String. The blob name.
      # * +options+         - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:start_range+    - Integer. Position of first byte of first page. (optional)
      # * +:end_range+      - Integer. Position of last byte of of last page. (optional)
      # * +:snapshot+       - String. An opaque DateTime value that specifies the blob snapshot to 
      #   retrieve information from. (optional)
      # * +:timeout+        - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691973.aspx
      #
      # Returns a list of page ranges in the format [ [start, end], [start, end], ... ]
      #
      #   eg. [ [0, 511], [512, 1024], ... ]
      #
      def list_page_blob_ranges(container, blob, options={})
        query = {"comp"=>"pagelist"}
        query.update({"snapshot" => options[:snapshot]}) if options[:snapshot]
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        options[:start_range] = 0 if options[:end_range] and not options[:start_range]

        headers = { }
        headers = { "x-ms-range" =>  "bytes=#{options[:start_range]}-#{options[:end_range]}" } if options[:start_range]

        response = call(:get, uri, nil, headers)

        pagelist = Serialization.page_list_from_xml(response.body)
        pagelist
      end

      # Public: Sets system properties defined for a blob.
      #
      # ==== Attributes
      #
      # * +container+      - String. The container name.
      # * +blob+           - String. The blob name.
      # * +options+         - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:content_type+             - String. Content type for the blob. Will be saved with blob.
      # * +:content_encoding+         - String. Content encoding for the blob. Will be saved with blob.
      # * +:content_language+         - String. Content language for the blob. Will be saved with blob.
      # * +:content_md5+              - String. Content MD5 for the blob. Will be saved with blob.
      # * +:cache_control+            - String. Cache control for the blob. Will be saved with blob.
      # * +:content_length+           - Integer. Resizes a page blob to the specified size. If the specified 
      #   value is less than the current size of the blob, then all pages above 
      #   the specified value are cleared. This property cannot be used to change 
      #   the size of a block blob. Setting this property for a block blob returns 
      #   status code 400 (Bad Request).
      # * +:sequence_number_action+   - Symbol. This property indicates how the service should modify the sequence 
      #   number for the blob. Required if :sequence_number is used. This property 
      #   applies to page blobs only.
      #
      #   Specify one of the following options for this property:
      #
      #   * +:max+        - Sets the sequence number to be the higher of the value included with 
      #     the request and the value currently stored for the blob.
      #   * +:update+     - Sets the sequence number to the value included with the request.
      #   * +:increment+  - Increments the value of the sequence number by 1. If specifying this 
      #     option, do not include the sequence_number option; doing so will return
      #     status code 400 (Bad Request).
      # * +:sequence_number+          - Integer. This property sets the blob's sequence number. The sequence number is a 
      #   user-controlled property that you can use to track requests and manage concurrency 
      #   issues. Required if the :sequence_number_action option is set to :max or :update. 
      #   This property applies to page blobs only.
      #
      #   Use this together with the :sequence_number_action to update the blob's sequence 
      #   number, either to the specified value or to the higher of the values specified with 
      #   the request or currently stored with the blob.
      #
      #   This header should not be specified if :sequence_number_action is set to :increment; 
      #   in this case the service automatically increments the sequence number by one.
      #
      #   To set the sequence number to a value of your choosing, this property must be specified
      #   together with :sequence_number_action
      # * +:timeout+                  - Integer. A timeout in seconds.
      #
      # Remarks:
      #
      # The semantics for updating a blob's properties are as follows:
      #
      # * A page blob's sequence number is updated only if the request meets either of the following conditions:
      # 
      #     * The :sequence_number_action property is set to :max or :update, and a value for :sequence_number is also set.
      #     * The :sequence_number_action property is set to :increment, indicating that the service should increment
      #       the sequence number by one.
      # 
      # * The size of the page blob is modified only if a value for :content_length is specified.
      #
      # * If :sequence_number and/or :content_length are the only properties specified, then the other properties of the blob
      #   will NOT be modified.
      # 
      # * If any one or more of the following properties are set, then all of these properties are set together. If a value is
      #   not provided for a given property when at least one of the properties listed below is set, then that property will be
      #   cleared for the blob.
      # 
      #     * :cache_control
      #     * :content_type
      #     * :content_md5
      #     * :content_encoding
      #     * :content_language
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691966.aspx
      #
      # Returns nil on success.
      def set_blob_properties(container, blob, options={})
        query = { "comp" => "properties" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]
        uri = blob_uri(container, blob, query)

        headers = { }

        unless options.empty?
          headers["x-ms-blob-content-type"] = options[:blob_content_type] if options[:blob_content_type]
          headers["x-ms-blob-content-encoding"] = options[:blob_content_encoding] if options[:blob_content_encoding]
          headers["x-ms-blob-content-language"] = options[:blob_content_language] if options[:blob_content_language]
          headers["x-ms-blob-content-md5"] = options[:blob_content_md5] if options[:blob_content_md5]
          headers["x-ms-blob-cache-control"] = options[:blob_cache_control] if options[:blob_cache_control]
          headers["x-ms-blob-content-length"] = options[:blob_content_length].to_s if options[:blob_content_length]
          headers["x-ms-blob-sequence-number-action"] = options[:sequence_number_action].to_s if options[:sequence_number_action]
          headers["x-ms-blob-sequence-number"] = options[:sequence_number].to_s if options[:sequence_number]
        end

        call(:put, uri, nil, headers)
        nil
      end

      # Public: Sets metadata headers on the blob.
      #
      # ==== Attributes
      #
      # * +container+      - String. The container name.
      # * +blob+           - String. The blob name.
      # * +metadata+       - Hash. The custom metadata.
      # * +options+        - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:timeout+       - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179414.aspx
      #
      # Returns nil on success.
      def set_blob_metadata(container, blob, metadata, options={})
        query = { "comp" => "metadata" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]
        uri = blob_uri(container, blob, query)

        headers = { }

        add_metadata_to_headers(metadata, headers) if metadata

        call(:put, uri, nil, headers)
        nil
      end

      # Public: Reads or downloads a blob from the system, including its metadata and properties.
      #
      # ==== Attributes
      #
      # * +container+        - String. The container name.
      # * +blob+             - String. The blob name.
      # * +options+          - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:start_range+     - Integer. Position of first byte of first page. (optional)
      # * +:end_range+       - Integer. Position of last byte of of last page. (optional)
      # * +:snapshot+        - String. An opaque DateTime value that specifies the blob snapshot to 
      #   retrieve information from. (optional)
      # * +:get_content_md5+ - Boolean. Return the MD5 hash for the range. This option only valid if
      #   start_range and end_range are specified. (optional)
      # * +:timeout+         - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179440.aspx
      #
      # Returns a blob and the blob body
      def get_blob(container, blob, options={})
        query = { }
        query["snapshot"] = options[:snapshot] if options[:snapshot]
        query["timeout"] = options[:timeout].to_s if options[:timeout]
        uri = blob_uri(container, blob, query)

        headers = { }
        options[:start_range] = 0 if options[:end_range] and not options[:start_range]
        if options[:start_range]
          headers["x-ms-range"] = "bytes=#{options[:start_range]}-#{options[:end_range]}"
          headers["x-ms-range-get-content-md5"] = true if options[:get_content_md5]
        end

        response = call(:get, uri, nil, headers)
        result = Serialization.blob_from_headers(response.headers)
        result.name = blob if not result.name
        return result, response.body
      end

      # Public: Deletes a blob or blob snapshot.
      #
      # ==== Attributes
      #
      # * +container+          - String. The container name.
      # * +blob+               - String. The blob name.
      # * +options+            - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:snapshot+          - String. An opaque DateTime value that specifies the blob snapshot to 
      #   retrieve information from. (optional)
      # * +:delete_snapshots+  - Symbol. Used to specify the scope of the delete operation for snapshots.
      #   This parameter is ignored if a blob does not have snapshots, or if a 
      #   snapshot is specified in the snapshot parameter. (optional)
      # 
      #   Possible values include:  
      #   * +:only+     - Deletes only the snapshots for the blob, but leaves the blob
      #   * +:include+  - Deletes the blob and all of the snapshots for the blob
      # * +:timeout+           - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd179440.aspx
      #
      # Returns nil on success
      def delete_blob(container, blob, options={})
        query = { }
        query["snapshot"] = options[:snapshot] if options[:snapshot]
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        options[:delete_snapshots] = :include if !options[:delete_snapshots]

        headers = { }
        headers["x-ms-delete-snapshots"] = options[:delete_snapshots].to_s if options[:delete_snapshots] && options[:snapshot] == nil

        call(:delete, uri, nil, headers)
        nil
      end

      # Public: Creates a snapshot of a blob.
      #
      # ==== Attributes
      #
      # * +container+       - String. The container name.
      # * +blob+            - String. The blob name.
      # * +options+         - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:metadata+                 - Hash. Custom metadata values to store with the blob snapshot.
      # * +:if_modified_since+        - A DateTime value. Specify this option to write the page only if the blob has been 
      #   modified since the specified date/time. If the blob has not been modified, the 
      #   Blob service returns status code 412 (Precondition Failed).
      # * +:if_unmodified_since+      - A DateTime value. Specify this option to write the page only if the blob has not 
      #   been modified since the specified date/time. If the blob has been modified, the 
      #   Blob service returns status code 412 (Precondition Failed).
      # * +:if_match+                 - An ETag value. Specify an ETag value to write the page only if the blob's ETag 
      #   value matches the value specified. If the values do not match, the Blob service 
      #   returns status code 412 (Precondition Failed).
      # * +:if_none_match+            - An ETag value. Specify an ETag value to write the page only if the blob's ETag 
      #   value does not match the value specified. If the values are identical, the Blob 
      #   service returns status code 412 (Precondition Failed).
      # * +:timeout+                  - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691971.aspx
      # 
      # Returns the snapshot DateTime value
      def create_blob_snapshot(container, blob, options={})
        query = { "comp" => "snapshot" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        headers = { }
        unless options.empty?
          add_metadata_to_headers(options[:metadata], headers) if options[:metadata]

          headers["If-Modified-Since"] = options[:if_modified_since] if options[:if_modified_since]
          headers["If-Unmodified-Since"] = options[:if_unmodified_since] if options[:if_unmodified_since]
          headers["If-Match"] = options[:if_match] if options[:if_match]
          headers["If-None-Match"] = options[:if_none_match] if options[:if_none_match]
        end

        response = call(:put, uri, nil, headers)

        response.headers["x-ms-snapshot"]
      end

      # Public: Copies a source blob to a destination blob within the same storage account.
      # 
      # ==== Attributes
      #
      # * +source_container+      - String. The destination container name to copy to.
      # * +source_blob+           - String. The destination blob name to copy to.
      # * +destination_container+ - String. The source container name to copy from.
      # * +destination_blob+      - String. The source blob name to copy from.
      # * +options+               - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:source_snapshot+            - String. A snapshot id for the source blob
      # * +:metadata+                   - Hash. Custom metadata values to store with the copy. If this parameter is not 
      #   specified, the operation will copy the source blob metadata to the destination 
      #   blob. If this parameter is specified, the destination blob is created with the 
      #   specified metadata, and metadata is not copied from the source blob.
      # * +:source_if_modified_since+   - A DateTime value. Specify this option to write the page only if the source blob 
      #   has been modified since the specified date/time. If the blob has not been 
      #   modified, the Blob service returns status code 412 (Precondition Failed).
      # * +:source_if_unmodified_since+ - A DateTime value. Specify this option to write the page only if the source blob
      #   has not been modified since the specified date/time. If the blob has been 
      #   modified, the Blob service returns status code 412 (Precondition Failed).
      # * +:source_if_match+            - An ETag value. Specify an ETag value to write the page only if the source blob's 
      #   ETag value matches the value specified. If the values do not match, the Blob 
      #   service returns status code 412 (Precondition Failed).
      # * +:source_if_none_match+       - An ETag value. Specify an ETag value to write the page only if the source blob's 
      #   ETag value does not match the value specified. If the values are identical, the 
      #   Blob service returns status code 412 (Precondition Failed).
      # * +:dest_if_modified_since+     - A DateTime value. Specify this option to write the page only if the destination 
      #   blob has been modified since the specified date/time. If the blob has not been 
      #   modified, the Blob service returns status code 412 (Precondition Failed).
      # * +:dest_if_unmodified_since+   - A DateTime value. Specify this option to write the page only if the destination 
      #   blob has not been modified since the specified date/time. If the blob has been 
      #   modified, the Blob service returns status code 412 (Precondition Failed).
      # * +:dest_if_match+              - An ETag value. Specify an ETag value to write the page only if the destination 
      #   blob's ETag value matches the value specified. If the values do not match, the 
      #   Blob service returns status code 412 (Precondition Failed).
      # * +:dest_if_none_match+         - An ETag value. Specify an ETag value to write the page only if the destination 
      #   blob's ETag value does not match the value specified. If the values are 
      #   identical, the Blob service returns status code 412 (Precondition Failed).
      # * +:timeout+                    - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/dd894037.aspx
      #
      # Returns a tuple of (copy_id, copy_status). 
      #
      # * +copy_id+     - String identifier for this copy operation. Use with get_blob or get_blob_properties to check 
      #   the status of this copy operation, or pass to abort_copy_blob to abort a pending copy.
      # * +copy_status+ - String. The state of the copy operation, with these values:
      #   "success" - The copy completed successfully.
      #   "pending" - The copy is in progress. 
      #
      def copy_blob(destination_container, destination_blob, source_container, source_blob, options={})
        query = { }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(destination_container, destination_blob, query)
        headers = { }
        headers["x-ms-copy-source"] = blob_uri(source_container, source_blob, options[:source_snapshot] ? { "snapshot" => options[:source_snapshot] } : {}).to_s

        unless options.empty?
          headers["If-Modified-Since"] = options[:dest_if_modified_since] if options[:dest_if_modified_since]
          headers["If-Unmodified-Since"] = options[:dest_if_unmodified_since] if options[:dest_if_unmodified_since]
          headers["If-Match"] = options[:dest_if_match] if options[:dest_if_match]
          headers["If-None-Match"] = options[:dest_if_none_match] if options[:dest_if_none_match]
          headers["x-ms-source-if-modified-since"] = options[:source_if_modified_since] if options[:source_if_modified_since]
          headers["x-ms-source-if-unmodified-since"] = options[:source_if_unmodified_since] if options[:source_if_unmodified_since]
          headers["x-ms-source-if-match"] = options[:source_if_match] if options[:source_if_match]
          headers["x-ms-source-if-none-match"] = options[:source_if_none_match] if options[:source_if_none_match]

          add_metadata_to_headers(options[:metadata], headers) if options[:metadata]
        end

        response = call(:put, uri, nil, headers)
        return response.headers["x-ms-copy-id"], response.headers["x-ms-copy-status"]
      end

      # Public: Establishes an exclusive one-minute write lock on a blob. To write to a locked
      # blob, a client must provide a lease ID.
      #
      # ==== Attributes
      #
      # * +container+          - String. The container name.
      # * +blob+               - String. The blob name.     
      # * +options+            - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are: 
      # * +:duration+          - Integer. Default -1. Specifies the duration of the lease, in seconds, or negative one (-1) 
      #   for a lease that never expires. A non-infinite lease can be between 15 and 60 seconds. (optional)
      # * +:proposed_lease_id+ - String. Proposed lease ID, in a GUID string format. The Blob service returns 400 (Invalid request)
      #   if the proposed lease ID is not in the correct format. (optional)
      # * +:timeout+           - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691972.aspx
      #
      # Returns a String of the new unique lease id. While the lease is active, you must include the lease ID with any request 
      # to write to the blob, or to renew, change, or release the lease. A successful renew operation also returns the lease id
      # for the active lease.
      #
      def acquire_lease(container, blob, options={})
        query = { "comp" => "lease" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        duration = -1
        duration = options[:duration] if options[:duration]

        headers = { }
        headers["x-ms-lease-action"] = "acquire"
        headers["x-ms-lease-duration"] = duration.to_s if duration
        headers["x-ms-proposed-lease-id"] = options[:proposed_lease_id] if options[:proposed_lease_id]

        response = call(:put, uri, nil, headers)
        response.headers["x-ms-lease-id"]
      end

      # Public: Renews the lease. The lease can be renewed if the lease ID specified on the request matches that 
      # associated with the blob. Note that the lease may be renewed even if it has expired as long as the blob 
      # has not been modified or leased again since the expiration of that lease. When you renew a lease, the 
      # lease duration clock resets.
      #
      # ==== Attributes
      #
      # * +container+         - String. The container name.
      # * +blob+              - String. The blob name.
      # * +lease+             - String. The lease id
      # * +options+           - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are: 
      # * +:timeout+          - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691972.aspx
      #
      # Returns the renewed lease id
      def renew_lease(container, blob, lease, options={})
        query = { "comp" => "lease" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        headers = { }
        headers["x-ms-lease-action"] = "renew"
        headers["x-ms-lease-id"] = lease

        response = call(:put, uri, nil, headers)
        response.headers["x-ms-lease-id"]
      end

      # Public: Releases the lease. The lease may be released if the lease ID specified on the request matches that 
      # associated with the blob. Releasing the lease allows another client to immediately acquire the lease for 
      # the blob as soon as the release is complete.
      #
      # ==== Attributes
      #
      # * +container+         - String. The container name.
      # * +blob+              - String. The blob name.
      # * +lease+             - String. The lease id.
      # * +options+           - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are: 
      # * +:timeout+          - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691972.aspx
      #
      # Returns nil on success
      def release_lease(container, blob, lease, options={})
        query = { "comp" => "lease" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        headers = { }
        headers["x-ms-lease-action"] = "release"
        headers["x-ms-lease-id"] = lease

        call(:put, uri, nil, headers)
        nil
      end

      # Public: Breaks the lease, if the blob has an active lease. Once a lease is broken, it cannot be renewed. Any 
      # authorized request can break the lease; the request is not required to specify a matching lease ID. When a 
      # lease is broken, the lease break period is allowed to elapse, during which time no lease operation except 
      # break and release can be performed on the blob. When a lease is successfully broken, the response indicates 
      # the interval in seconds until a new lease can be acquired.
      #
      # A lease that has been broken can also be released, in which case another client may immediately acquire the 
      # lease on the blob.
      #
      # ==== Attributes
      #
      # * +container+         - String. The container name.
      # * +blob+              - String. The blob name.
      # * +options+           - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are: 
      # * +:break_period+     - Integer. The proposed duration of seconds that the lease should continue before it is 
      #   broken, between 0 and 60 seconds. This break period is only used if it is shorter than 
      #   the time remaining on the lease. If longer, the time remaining on the lease is used. A 
      #   new lease will not be available before the break period has expired, but the lease may 
      #   be held for longer than the break period.
      #
      #   If this option is not used, a fixed-duration lease breaks after the remaining lease 
      #   period elapses, and an infinite lease breaks immediately.
      # * +:timeout+          - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/windowsazure/ee691972.aspx
      #
      # Returns an Integer of the remaining lease time. This value is the approximate time remaining in the lease 
      # period, in seconds. This header is returned only for a successful request to break the lease. If the break 
      # is immediate, 0 is returned.
      def break_lease(container, blob, options={})
        query = { "comp" => "lease" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = blob_uri(container, blob, query)

        headers = { }
        headers["x-ms-lease-action"] = "break"
        headers["x-ms-lease-break-period"] = options[:break_period].to_s if options[:break_period]

        response = call(:put, uri, nil, headers)
        response.headers["x-ms-lease-time"].to_i
      end

      # Protected: Generate the URI for the collection of containers.
      #
      # ==== Attributes
      #
      # * +query+ - A Hash of key => value query parameters.
      # * +host+  - The host of the API.
      #
      # Returns a URI.
      protected
      def containers_uri(query={})
        query = { "comp" => "list" }.merge(query)
        generate_uri("/", query)
      end

      # Protected: Generate the URI for a specific container.
      #
      # ==== Attributes
      #
      # * +name+  - The container name. If this is a URI, we just return this.
      # * +query+ - A Hash of key => value query parameters.
      # * +host+  - The host of the API.
      #
      # Returns a URI.
      protected
      def container_uri(name, query={})
        return name if name.kind_of? ::URI
        query = { "restype" => "container" }.merge(query)
        generate_uri(name, query)
      end

      # Protected: Generate the URI for a specific Blob.
      #
      # ==== Attributes
      #
      # * +container_name+ - String representing the name of the container.
      # * +blob_name+      - String representing the name of the blob.
      # * +query+          - A Hash of key => value query parameters.
      # * +host+           - The host of the API.
      #
      # Returns a URI.
      protected
      def blob_uri(container_name, blob_name, query={})
        blob_name = CGI.escape(blob_name)

        # Unencode the forward slashes to match what the server expects.
        blob_name = blob_name.gsub(/%2F/, '/')
        # Unencode the backward slashes to match what the server expects.
        blob_name = blob_name.gsub(/%5C/, '/')
        # Re-encode the spaces (encoded as space) to the % encoding.
        blob_name = blob_name.gsub(/\+/, '%20')

        if container_name.nil? || container_name.empty?
          path = blob_name
        else
          path = File.join(container_name, blob_name)
        end

        generate_uri(path, query)
      end
    end
  end
end