#-------------------------------------------------------------------------
# # Copyright (c) Microsoft and contributors. 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/queue/serialization'

module Azure
  module Queue
    class QueueService < Service::StorageService

      def initialize(options = {})
        super(nil, nil, options)
        @host = @client.storage_queue_host
      end

      # Public: Get a list of Queues 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 queue 
      # 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/azure/dd179466 
      #
      # 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_queues(options={})
        query = { }
        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]

        uri = collection_uri(query)
        response = call(:get, uri)

        Serialization.queue_enumeration_results_from_xml(response.body)
      end

      # Public: Clears all messages from the queue.
      # 
      # If a queue contains a large number of messages, Clear Messages may time out 
      # before all messages have been deleted. In this case the Queue service will 
      # return status code 500 (Internal Server Error), with the additional error 
      # code OperationTimedOut. If the operation times out, the client should 
      # continue to retry Clear Messages until it succeeds, to ensure that all 
      # messages have been deleted.
      # 
      # ==== Attributes
      #
      # * +queue_name+ - String. The name of the queue.
      # * +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/azure/dd179454
      # 
      # Returns nil on success
      def clear_messages(queue_name, options={})
        query = { }
        query["timeout"] = options[:timeout].to_s if options[:timeout]
        uri = messages_uri(queue_name, query)
        call(:delete, uri)
        nil
      end
    
      # Public: Creates a new queue under the storage account.
      # 
      # ==== Attributes
      #
      # * +queue_name+     - String. The queue name.
      # * +options+        - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:metadata+      - Hash. A hash of user defined metadata.
      # * +:timeout+       - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/azure/dd179342
      #
      # Returns nil on success
      def create_queue(queue_name, options={})
        query = { }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = queue_uri(queue_name, query)

        headers = { }
        add_metadata_to_headers(options[:metadata] || {}, headers) if options[:metadata]

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

      # Public: Deletes a queue.
      # 
      # ==== Attributes
      #
      # * +queue_name+     - String. The queue name.
      # * +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/azure/dd179436
      #
      # Returns nil on success
      def delete_queue(queue_name, options={})
        query = { }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = queue_uri(queue_name, query)

        call(:delete, uri)
        nil
      end

      # Public: Returns queue properties, including user-defined metadata.
      # 
      # ==== Attributes
      #
      # * +queue_name+     - String. The queue name.
      # * +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/azure/dd179384
      #
      # Returns a tuple of (approximate_message_count, metadata)
      # * approximate_messages_count  - Integer. The approximate number of messages in the queue. This number is not
      #   lower than the actual number of messages in the queue, but could be higher.
      # * metadata                    - Hash. The queue metadata (Default: {})
      #
      def get_queue_metadata(queue_name, options={})
        query = { "comp" => "metadata" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = queue_uri(queue_name, query)

        response = call(:get, uri)

        approximate_messages_count = response.headers["x-ms-approximate-messages-count"]
        metadata = Serialization.metadata_from_headers(response.headers)

        return approximate_messages_count.to_i, metadata
      end

      # Public: Sets user-defined metadata on the queue. To delete queue metadata, call 
      # this API with an empty hash in the metadata parameter.
      # 
      # ==== Attributes
      #
      # * +queue_name+ - String. The queue name.
      # * +metadata+   - Hash. A hash of user defined 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/azure/dd179348
      #
      # Returns nil on success
      def set_queue_metadata(queue_name, metadata, options={})
        query = { "comp" => "metadata" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = queue_uri(queue_name, query)

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

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

      # Public: Gets the access control list (ACL) for the queue.
      #
      # ==== Attributes
      #
      # * +queue_name+ - String. The queue name.
      # * +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/azure/jj159101
      #
      # Returns a list of Azure::Entity::SignedIdentifier instances
      def get_queue_acl(queue_name, options={})
        query = { "comp" => "acl" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        response = call(:get, queue_uri(queue_name, query))

        signed_identifiers = []
        signed_identifiers = Serialization.signed_identifiers_from_xml(response.body) unless response.body == nil or response.body.length < 1
        signed_identifiers
      end

      # Public: Sets the access control list (ACL) for the queue.
      #
      # ==== Attributes
      #
      # * +queue_name+ - String. The queue name.
      # * +options+    - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:signed_identifiers+  - Array. A list of Azure::Entity::SignedIdentifier instances 
      # * +:timeout+             - Integer. A timeout in seconds.
      # 
      # See http://msdn.microsoft.com/en-us/library/azure/jj159099
      #
      # Returns nil on success
      def set_queue_acl(queue_name, options={})
        query = { "comp" => "acl" }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri =queue_uri(queue_name, query)
        body = nil
        body = Serialization.signed_identifiers_to_xml(options[:signed_identifiers]) if options[:signed_identifiers] && options[:signed_identifiers].length > 0

        call(:put, uri, body, {})
        nil
      end

      # Public: Adds a message to the queue and optionally sets a visibility timeout for the message.
      # 
      # ==== Attributes
      #
      # * +queue_name+   - String. The queue name.
      # * +message_text+ - String. The message contents. Note that the message content must be in a format that may be encoded with UTF-8.
      # * +options+      - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:visibility_timeout+     - Integer. Specifies the new visibility timeout value, in seconds, relative to server 
      #   time. The new value must be larger than or equal to 0, and cannot be larger than 7 
      #   days. The visibility timeout of a message cannot be set to a value later than the 
      #   expiry time. :visibility_timeout should be set to a value smaller than the 
      #   time-to-live value. If not specified, the default value is 0.
      # * +:message_ttl+            - Integer. Specifies the time-to-live interval for the message, in seconds. The maximum 
      #   time-to-live allowed is 7 days. If not specified, the default time-to-live is 7 days.
      # * +:encode+                 - Boolean. If set to true, the message will be base64 encoded.
      # * +:timeout+                - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/azure/dd179346
      #
      # Returns nil on success
      def create_message(queue_name, message_text, options={})
        query = { }

        unless options.empty?
          query["visibilitytimeout"] = options[:visibility_timeout] if options[:visibility_timeout]
          query["messagettl"] = options[:message_ttl] if options[:message_ttl]
          query["timeout"] = options[:timeout].to_s if options[:timeout]
        end

        uri = messages_uri(queue_name, query)
        body = Serialization.message_to_xml(message_text, options[:encode])

        call(:post, uri, body, {})
        nil
      end

      # Public: Deletes a specified message from the queue.
      # 
      # ==== Attributes
      #
      # * +queue_name+   - String. The queue name.
      # * +message_id+   - String. The id of the message.
      # * +pop_receipt+  - String. The valid pop receipt value returned from an earlier call to the Get Messages or 
      #   Update Message operation.
      # * +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/azure/dd179347
      #
      # Returns nil on success
      #
      # Remarks:
      #
      # When a message is successfully deleted, it is immediately marked for deletion and is no longer accessible to 
      # clients. The message is later removed from the queue during garbage collection.
      # 
      # After a client retrieves a message with the Get Messages operation, the client is expected to process and 
      # delete the message. To delete the message, you must have two items of data returned in the response body of 
      # the Get Messages operation:
      # 
      # * The message ID, an opaque GUID value that identifies the message in the queue.
      # 
      # * A valid pop receipt, an opaque value that indicates that the message has been retrieved.
      # 
      # The message ID is returned from the previous Get Messages operation. The pop receipt is returned from the most 
      # recent Get Messages or Update Message operation. In order for the Delete Message operation to succeed, the pop 
      # receipt specified on the request must match the pop receipt returned from the Get Messages or Update Message 
      # operation.
      # 
      # Pop receipts remain valid until one of the following events occurs:
      #
      # * The message has expired.
      #
      # * The message has been deleted using the last pop receipt received either from Get Messages or Update Message. 
      # 
      # * The invisibility time has elapsed and the message has been dequeued by a Get Messages request. When the 
      # invisibility time elapses, the message becomes visible again. If it is retrieved by another Get Messages 
      # request, the returned pop receipt can be used to delete or update the message.
      # 
      # * The message has been updated with a new visibility timeout. When the message is updated, a new pop receipt 
      # will be returned.
      # 
      # If the message has already been deleted when Delete Message is called, the Queue service returns status code 
      # 404 (Not Found).
      # 
      # If a message with a matching pop receipt is not found, the service returns status code 400 (Bad Request), with 
      # additional error information indicating that the cause of the failure was a mismatched pop receipt.
      #
      def delete_message(queue_name, message_id, pop_receipt, options={})
        query = { "popreceipt" => pop_receipt }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = message_uri(queue_name, message_id, query)

        call(:delete, uri)
        nil
      end

      # Public: Retrieves one or more messages from the front of the queue, without changing the message visibility.
      #
      # ==== Attributes
      #
      # * +queue_name+   - String. The queue name.
      # * +options+      - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:number_of_messages+ - Integer. How many messages to return. (optional, Default: 1)
      # * +:decode+             - Boolean. Boolean value indicating if the message should be base64 decoded.
      # * +:timeout+            - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/azure/dd179472
      #
      # Returns a list of Azure::Entity::Queue::Message instances
      def peek_messages(queue_name, options={})
        number_of_messages=1
        number_of_messages = options[:number_of_messages] if options[:number_of_messages]

        query = { "peekonly" => "true", "numofmessages"=> number_of_messages.to_s }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = messages_uri(queue_name, query)
        response = call(:get, uri)

        messages = Serialization.queue_messages_from_xml(response.body, options[:decode])
        messages
      end

      # Public: Retrieves one or more messages from the front of the queue.
      #
      # ==== Attributes
      #
      # * +queue_name+          - String. The queue name.
      # * +visibility_timeout+  - Integer. The new visibility timeout value, in seconds, relative to server time.
      # * +options+             - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:number_of_messages+ - Integer. How many messages to return. (optional, Default: 1)
      # * +:timeout+            - Integer. A timeout in seconds.
      # * +:decode+             - Boolean. Boolean value indicating if the message should be base64 decoded.
      #
      # See http://msdn.microsoft.com/en-us/library/azure/dd179474
      #
      # Returns a list of Azure::Entity::Queue::Message instances
      def list_messages(queue_name, visibility_timeout, options={})
        number_of_messages=1
        number_of_messages = options[:number_of_messages] if options[:number_of_messages]

        query = { "visibilitytimeout" => visibility_timeout.to_s, "numofmessages"=> number_of_messages.to_s }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = messages_uri(queue_name, query)
        response = call(:get, uri)

        messages = Serialization.queue_messages_from_xml(response.body, options[:decode])
        messages
      end

      # Public: Adds a message to the queue and optionally sets a visibility timeout for the message.
      # 
      # ==== Attributes
      #
      # * +queue_name+         - String. The queue name.
      # * +message_id+         - String. The id of the message.
      # * +pop_receipt+        - String. The valid pop receipt value returned from an earlier call to the Get Messages or 
      #   update Message operation.
      # * +message_text+       - String. The message contents. Note that the message content must be in a format that may 
      #   be encoded with UTF-8.
      # * +visibility_timeout+ - Integer. The new visibility timeout value, in seconds, relative to server time.
      # * +options+            - Hash. Optional parameters. 
      #
      # ==== Options
      #
      # Accepted key/value pairs in options parameter are:
      # * +:encode+                 - Boolean. If set to true, the message will be base64 encoded.
      # * +:timeout+           - Integer. A timeout in seconds.
      #
      # See http://msdn.microsoft.com/en-us/library/azure/hh452234
      #
      # Returns a tuple of (pop_receipt, time_next_visible)
      # * pop_receipt        - String. The pop receipt of the queue message.
      # * time_next_visible  - String. A UTC date/time value that represents when the message will be visible on the queue.
      #
      # Remarks:
      #
      # An Update Message operation will fail if the specified message does not exist in the queue, or if the 
      # specified pop receipt does not match the message.
      # 
      # A pop receipt is returned by the Get Messages operation or the Update Message operation. Pop receipts 
      # remain valid until one of the following events occurs:
      # 
      # * The message has expired.
      # 
      # * The message has been deleted using the last pop receipt received either from Get Messages or 
      # Update Message. 
      # 
      # * The invisibility time has elapsed and the message has been dequeued by a Get Messages request. When 
      # the invisibility time elapses, the message becomes visible again. If it is retrieved by another 
      # Get Messages request, the returned pop receipt can be used to delete or update the message.
      # 
      # * The message has been updated with a new visibility timeout. When the message is updated, a new pop 
      # receipt will be returned.
      # 
      # The Update Message operation can be used to continually extend the invisibility of a queue message. This 
      # functionality can be useful if you want a worker role to "lease" a queue message. For example, if a worker 
      # role calls Get Messages and recognizes that it needs more time to process a message, it can continually 
      # extend the message's invisibility until it is processed. If the worker role were to fail during processing, 
      # eventually the message would become visible again and another worker role could process it.
      #
      def update_message(queue_name, message_id, pop_receipt, message_text, visibility_timeout, options={})
        query = { "visibilitytimeout" => visibility_timeout.to_s, "popreceipt" => pop_receipt }
        query["timeout"] = options[:timeout].to_s if options[:timeout]

        uri = message_uri(queue_name, message_id, query)
        body = Serialization.message_to_xml(message_text, options[:encode])

        response = call(:put, uri, body, {})
        new_pop_receipt = response.headers["x-ms-popreceipt"]
        time_next_visible = response.headers["x-ms-time-next-visible"]
        return new_pop_receipt, time_next_visible
      end

      # Protected: Generate the URI for the collection of queues.
      #
      # ==== Attributes
      #
      # * +query+      - A Hash of query parameters (default: {}).
      #
      # Returns a URI.
      protected
      def collection_uri(query={})
        query.update({:comp => 'list', :include => 'metadata'})
        generate_uri("", query)
      end

      # Protected: Generate the URI for a given queue.
      #
      # ==== Attributes
      #
      # * +queue_name+ - The name of the queue.
      # * +query+      - A Hash of query parameters (default: {}).
      #
      # Returns a URI.
      protected
      def queue_uri(queue_name, query={})
        return queue_name if queue_name.kind_of? ::URI
        generate_uri(queue_name, query)
      end

      # Protected: Generate the messages URI for the given queue.
      #
      # ==== Attributes
      #
      # * +queue_name+ - The name of the queue.
      # * +query+      - A Hash of query parameters (default: {}).
      #
      # Returns a URI.
      protected
      def messages_uri(queue_name, query={})
        generate_uri("#{queue_name}/messages", query)
      end

      # Protected: Generate the URI for a given message
      #
      # ==== Attributes
      #
      # * +queue_name+ - The name of the queue.
      # * +message_id+ - The id of the message.
      # * +query+      - A Hash of query parameters (default: {}).
      #
      # Returns a URI.
      protected
      def message_uri(queue_name, message_id, query={})
        generate_uri("#{queue_name}/messages/#{message_id}", query)
      end
    end
  end
end

Azure::QueueService = Azure::Queue::QueueService