module AlsoMigrate
  module Migration
    
    def self.included(base)
      unless base.respond_to?(:method_missing_with_also_migrate)
        base.extend ClassMethods
        base.class_eval do
          class <<self
            alias_method :method_missing_without_also_migrate, :method_missing
            alias_method :method_missing, :method_missing_with_also_migrate
          end
        end
      end
    end

    module ClassMethods

      def method_missing_with_also_migrate(method, *arguments, &block)
        args = Marshal.load(Marshal.dump(arguments))
        method_missing_without_also_migrate(method, *arguments, &block)

        supported = [
          :add_column, :add_index, :add_timestamps, :change_column,
          :change_column_default, :change_table, :create_table,
          :drop_table, :remove_column, :remove_columns,
          :remove_timestamps, :rename_column, :rename_table
        ]

        if !args.empty? && supported.include?(method)
          connection = ActiveRecord::Base.connection
          table_name = ActiveRecord::Migrator.proper_table_name(args[0])
          
          # Find models
          if ::AlsoMigrate.classes
            ::AlsoMigrate.classes.uniq.each do |klass|
              if klass.also_migrate_config
                klass.also_migrate_config.each do |config|
                  options = config[:options]
                  tables = config[:tables]
                  
                  next unless config[:table_name] == table_name
              
                  # Don't change ignored columns
                  options[:ignore].each do |column|
                    next if args.include?(column) || args.include?(column.intern)
                  end

                  # Run migration
                  config[:tables].each do |table|
                    if method == :create_table
                      ActiveRecord::Migrator::AlsoMigrate.create_tables(klass)
                    elsif method == :add_index && !options[:indexes].nil?
                      next
                    elsif connection.table_exists?(table)
                      args[0] = table
                      args[1] = table if method == :rename_table
                      begin
                        connection.send(method, *args, &block)
                      rescue Exception => e
                        puts "(also_migrate warning) #{e.message}"
                      end
                    end
                  end
                end
              end
            end
          end
        end
      end
    end
  end
end