download.rb in rapidshare-ext-0.1.0

- old
+ new
@@ -1,47 +1,119 @@
 module Rapidshare
   module Ext
 
-    # Note from odiszapc:
+    # Downloads files from Rapidshare. Separate from +Rapidshare::API+ class because
+    # downloading is much more complex than other service calls.
     #
+    # Displays text progress bar during download.
+    #
+    # Note from odiszapc:
     # 1 oct 2012 the Rapidshare download API (http://images.rapidshare.com/apidoc.txt) was changed
     # so the base download function provided by rapidshare gem became broken
     #
     # In the original method the parameter :filename being interpreted incorrectly now.
-    # It's being interpreted like a "save file as" parameter. Actually it must be equal to the file name you want to download
+    # It's being interpreted like a 'save file as' parameter. Actually it must be equal to the file name you want to download
     # So, to download file now you must specify exactly two parameters: file id and file name.
-    class Download < Rapidshare::Download
+    class Download
+      DOWNLOAD_URL = 'https://rs%s%s.rapidshare.com/cgi-bin/rsapi.cgi?%s'
 
+      attr_reader :url, :api, :fileid, :filename, :filesize, :server_id,
+                  :short_host, :downloads_dir, :downloaded, :error
+
       # Options:
       # * *filename* (optional) - specifies filename under which the file will be
       #   saved. Default: filename parsed from Rapidshare link.
       # * *downloads_dir* (optional) - specifies directory into which downloaded files
       #   will be saved. Default: current directory.
       #
       def initialize(url, api, options = {})
-        super
+        @url = url
+        @api = api
+        @filename = options[:save_as]
+        @downloads_dir = options[:downloads_dir] || Dir.pwd
+
+        # OPTIMIZE replace these simple status variables with status codes
+        # and corresponding errors like "File not found"
+        #
+        # set to true when file is successfully downloaded
+        @downloaded = false
+        # non-critical error is stored here, beside being displayed
+        @error = nil
+
         @local_filename = options[:save_as]
         @filename = nil # It will be filled automatically by the #check method of the base class
       end
 
       # Checks if file exists (using checkfiles service) and gets data necessary for download.
       #
       # Returns true or false, which determines whether the file can be downloaded.
       #
       def check
-        res = super
-        if res
+        # PS: Api#checkfiles throws exception when file cannot be found
+        response = @api.checkfiles(@url).first rescue {}
+
+        if response[:file_status] == :ok
+          @fileid = response[:file_id]
+          @filename ||= response[:file_name]
+          @filesize = response[:file_size].to_i
+          @server_id = response[:server_id]
+          @short_host = response[:short_host]
+
           @remote_filename = @filename
           @filename = @local_filename || @remote_filename
+          true
+        else
+          # TODO report errors according to actual file status
+          @error = 'File not found'
+          false
         end
-        res
       end
 
+      # Downloads file. Calls +check+ method first.
+      # When block is given a custom progress bar interpretation can be implemented
+      def perform
+        # before downloading we have to check if file exists. checkfiles service
+        # also gives us information for the download: hostname, file size for
+        # progressbar
+        return self unless self.check
+
+        file = open(File.join(@downloads_dir, @filename), 'wb')
+        block_response = Proc.new do |response|
+          downloaded = 0
+          total = response.header['content-length'].to_i
+
+          unless total == @filesize
+            @error = 'Access denied'
+            return self
+          end
+
+          response.read_body do |chunk|
+            file << chunk
+            downloaded += chunk.size
+            progress = ((downloaded * 100).to_f / total).round(2)
+            yield chunk.size, downloaded, total, progress if block_given?
+          end
+        end
+
+        RestClient::Request.execute(:method => :get,
+                                    :url => self.download_link,
+                                    :block_response => block_response)
+        file.close()
+        @downloaded = true
+        self
+      end
+
       # Generates link which downloads file by Rapidshare API
       #
       def download_link
         download_params = { :sub => 'download', :fileid => @fileid, :filename => @remote_filename, :cookie => @api.cookie }
         DOWNLOAD_URL % [ @server_id, @short_host, download_params.to_query ]
+      end
+
+      # Says whether file has been successfully downloaded.
+      #
+      def downloaded?
+        @downloaded
       end
     end
   end
 end
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