adding legacy migration rake task

TODO

@@ -3,11 +3,6 @@ Fixes
 - fix image links on contest page
 
 Legacy Migration
-- add rake task to handle switch
-- split episode files into separate download records
-- delete comments marked as spam
-- translate code blocks in episode show notes
-- compare schema files to find other differences
 - fill initial sponsors
 
 Additional Features

lib/tasks/application.rake

@@ -0,0 +1,72 @@
+namespace :legacy do
+  desc "Migrate database from old railscasts site"
+  task :migrate => :environment do
+    require 'mysql'
+    $db = Mysql.connect('localhost', 'root', ENV['DBPW'], 'railscasts_legacy')
+
+    puts "starting episodes"
+    migrate_model Episode, 'episodes' do |row|
+      notes = row[:notes] || ''
+      notes.gsub!(/<code lang="(.+)">/, '@@@ \1')
+      notes.gsub!("</code>", "@@@")
+      row.slice(:id, :name, :published_at, :position, :description, :permalink).merge(:notes => notes)
+    end
+
+    puts "starting tags"
+    migrate_model Tag, 'tags' do |row|
+      row
+    end
+
+    puts "starting taggings"
+    migrate_model Tagging, 'episodes_tags' do |row|
+      row
+    end
+
+    puts "starting downloads"
+    migrate_model Download, 'episodes' do |row|
+      min, sec = *row[:duration].split(':').map(&:to_i)
+      seconds = min*60 + sec
+      [
+        {
+          :episode_id => row[:id],
+          :format => 'mov',
+          :url => "http://media.railscasts.com/videos/#{row[:file_name]}.mov",
+          :seconds => seconds,
+          :bytes => row[:file_size]
+        },
+        {
+          :episode_id => row[:id],
+          :format => 'm4v',
+          :url => "http://media.railscasts.com/ipod_videos/#{row[:file_name]}.m4v",
+          :seconds => seconds,
+          :bytes => row[:ipod_file_size]
+        }
+      ]
+    end
+
+    # puts "starting comments"
+    # migrate_model Comment, "comments WHERE approved='1' AND id NOT IN (39396, 39422)" do |row|
+    #   row.except(:approved)
+    # end
+  end
+
+  def migrate_model(model_class, table_name)
+    model_class.delete_all
+    rows = $db.query("SELECT * FROM #{table_name}")
+    rows.each_hash do |row|
+      insert_row(model_class, yield(row.symbolize_keys))
+    end
+  end
+
+  def insert_row(model_class, row)
+    if row.kind_of? Array
+      row.each { |r| insert_row(model_class, r) }
+    else
+      record = model_class.new
+      row.each do |name, value| # loop so we don't have mass assignment problems
+        record.write_attribute(name, value)
+      end
+      record.save(false) # skips validation
+    end
+  end
+end