#1866: Support twitpic source rewriting

* html work page -> full image
* thumbnail -> full image

app/logical/downloads/file.rb

@@ -69,7 +69,7 @@ module Downloads
                 if limit == 0 then
                   raise Error.new("Too many redirects")
                 end
-                source = res["location"]
+                @source = res["location"]
                 limit -= 1
 
               else

app/logical/downloads/strategies/base.rb

@@ -2,7 +2,7 @@ module Downloads
   module Strategies
     class Base
       def self.strategies
-        [Pixiv]
+        [Pixiv, Twitpic]
       end
 
       def rewrite(url, headers)

app/logical/downloads/strategies/twitpic.rb

@@ -0,0 +1,36 @@
+module Downloads
+  module Strategies
+    class Twitpic < Base
+      def rewrite(url, headers)
+        if url =~ %r{http://twitpic\.com} || url =~ %r{^http://d3j5vwomefv46c\.cloudfront\.net}
+          url, headers = rewrite_html_pages(url, headers)
+          url, headers = rewrite_thumbnails(url, headers)
+        end
+
+        return [url, headers]
+      end
+
+    protected
+      def rewrite_html_pages(url, headers)
+        # example: http://twitpic.com/cpprns
+
+        if url =~ %r{http://twitpic\.com/([a-z0-9]+)$}
+          id = $1
+          url = "http://twitpic.com/show/full/#{id}"
+          return [url, headers]
+        else
+          return [url, headers]
+        end
+      end
+
+      def rewrite_thumbnails(url, headers)
+        if url =~ %r{^http://d3j5vwomefv46c\.cloudfront\.net/photos/thumb/(\d+\..+)$}
+          match = $1
+          url.sub!("/thumb/" + match, "/large/" + match)
+        end
+
+        return [url, headers]
+      end
+    end
+  end
+end

test/unit/downloads/twitpic_test.rb

@@ -0,0 +1,44 @@
+require 'test_helper'
+
+module Downloads
+  class TwitpicTest < ActiveSupport::TestCase
+    context "a download for a twitpic html page" do
+      setup do
+        @source = "http://twitpic.com/cpprns"
+        @tempfile = Tempfile.new("danbooru-test")
+        @download = Downloads::File.new(@source, @tempfile.path)
+        VCR.use_cassette("download-twitpic-html", :record => :new_episodes) do
+          @download.download!
+        end
+      end
+
+      should "set the direct image link as the source" do
+        assert_equal("http://d3j5vwomefv46c.cloudfront.net/photos/large/768786760.jpg?1368245083", @download.source)
+      end
+
+      should "work" do
+        puts ::File.read(@tempfile.path).inspect
+        assert_equal(89_409, ::File.size(@tempfile.path))
+      end
+    end
+
+    context "a download for a twitpic thumbnail" do
+      setup do
+        @source = "http://d3j5vwomefv46c.cloudfront.net/photos/thumb/768786760.jpg?1368245083"
+        @tempfile = Tempfile.new("danbooru-test")
+        @download = Downloads::File.new(@source, @tempfile.path)
+        VCR.use_cassette("download-twitpic-thumb", :record => :new_episodes) do
+          @download.download!
+        end
+      end
+
+      should "instead download the original version" do
+        assert_equal("http://d3j5vwomefv46c.cloudfront.net/photos/large/768786760.jpg?1368245083", @download.source)
+      end
+
+      should "work" do
+        assert_equal(89_409, ::File.size(@tempfile.path))
+      end
+    end
+  end
+end