module ActiveRecord
  module ConnectionAdapters
    module SchemaStatements
      def quote_column_names(column_name)
        Array(column_name).map { |e| quote_column_name(e) }.join(", ")
      end

      def add_primary_key(table_name, column_name, options = {})
        column_names = Array(column_name)
        quoted_column_names = column_names.map { |e| quote_column_name(e) }.join(", ")
        execute "ALTER TABLE #{table_name} ADD PRIMARY KEY (#{quoted_column_names})"
      end

      def remove_primary_key(table_name)
        execute "ALTER TABLE #{table_name} DROP PRIMARY KEY"
      end

      def add_foreign_key(table_name, column_name, reftbl, refcol = nil)
        execute "ALTER TABLE #{table_name} ADD " +
          "FOREIGN KEY (#{quote_column_names(column_name)}) " +
          "REFERENCES #{reftbl} (#{quote_column_names(refcol || column_name)})"
      end

      def remove_foreign_key(table_name, column_name, reftbl, refcol = nil)
        execute "ALTER TABLE #{table_name} DROP " +
          "CONSTRAINT #{table_name}_#{column_name[0]}_fkey"
      end

      alias_method :old_options_include_default?, :options_include_default?

      def options_include_default?(options)
        return false if options[:options] =~ /AUTO_INCREMENT/i
        return old_options_include_default?(options)
      end

      alias_method :old_add_column_options!, :add_column_options!

      def add_column_options!(sql, options)
        sql << " UNSIGNED" if options[:unsigned]
        old_add_column_options!(sql, options)
        sql << " #{options[:options]}"
      end
    end

    if defined?(ActiveRecord::ConnectionAdapters::MysqlAdapter)
      class MysqlAdapter
        alias_method :old_native_database_types, :native_database_types

        def native_database_types
          types = old_native_database_types
          types[:bigint] = { :name => "bigint", :limit => 20 }
          types[:double] = { :name => "double" }
          types[:integer_pk] = { :name => "integer DEFAULT NULL auto_increment PRIMARY KEY" }
          types[:bigint_pk] = { :name => "bigint(20) DEFAULT NULL auto_increment PRIMARY KEY" }
          types[:bigint_pk_64] = { :name => "bigint(64) DEFAULT NULL auto_increment PRIMARY KEY" }
          types[:bigint_auto_64] = { :name => "bigint(64) DEFAULT NULL auto_increment" }
          types[:bigint_auto_11] = { :name => "bigint(11) DEFAULT NULL auto_increment" }
          types[:bigint_auto_20] = { :name => "bigint(20) DEFAULT NULL auto_increment" }
          types[:four_byte_unsigned] = { :name=> "integer unsigned" }
          types[:inet] = { :name=> "integer unsigned" }

          enumerations.each do |e,v|
            types[e.to_sym]= { :name => "enum('#{v.join '\',\''}')" }
          end

          types
        end

        def change_column(table_name, column_name, type, options = {})
          unless options_include_default?(options)
            options[:default] = select_one("SHOW COLUMNS FROM #{table_name} LIKE '#{column_name}'")["Default"]

            unless type == :string or type == :text
              options.delete(:default) if options[:default] = "";
            end
          end

          change_column_sql = "ALTER TABLE #{table_name} CHANGE #{column_name} #{column_name} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
          add_column_options!(change_column_sql, options)
          execute(change_column_sql)
        end

        def myisam_table
          return { :id => false, :force => true, :options => "ENGINE=MyIsam" }
        end

        def innodb_table
          return { :id => false, :force => true, :options => "ENGINE=InnoDB" }
        end

        def innodb_option
          return "ENGINE=InnoDB"
        end

        def change_engine (table_name, engine)
          execute "ALTER TABLE #{table_name} ENGINE = #{engine}"
        end

        def add_fulltext_index (table_name, column)
          execute "CREATE FULLTEXT INDEX `#{table_name}_#{column}_idx` ON `#{table_name}` (`#{column}`)"
        end

        def enumerations
          @enumerations ||= Hash.new
        end

        def create_enumeration (enumeration_name, values)
          enumerations[enumeration_name] = values
        end

        def drop_enumeration (enumeration_name)
          enumerations.delete(enumeration_name)
        end

        def alter_primary_key(table_name, new_columns)
          execute("alter table #{table_name} drop primary key, add primary key (#{new_columns.join(',')})")
        end

        def interval_constant(interval)
          "'#{interval}'"
        end
      end
    end

    if defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
      class PostgreSQLAdapter
        alias_method :old_native_database_types, :native_database_types

        def native_database_types
          types = old_native_database_types
          types[:double] = { :name => "double precision" }
          types[:integer_pk] = { :name => "serial PRIMARY KEY" }
          types[:bigint_pk] = { :name => "bigserial PRIMARY KEY" }
          types[:bigint_pk_64] = { :name => "bigserial PRIMARY KEY" }
          types[:bigint_auto_64] = { :name => "bigint" } #fixme: need autoincrement?
          types[:bigint_auto_11] = { :name => "bigint" } #fixme: need autoincrement?
          types[:bigint_auto_20] = { :name => "bigint" } #fixme: need autoincrement?
          types[:four_byte_unsigned] = { :name => "bigint" } # meh
          types[:inet] = { :name=> "inet" }

          enumerations.each_key do |e|
            types[e.to_sym]= { :name => e }
          end

          types
        end

        def myisam_table
          return { :id => false, :force => true, :options => ""}
        end

        def innodb_table
          return { :id => false, :force => true, :options => ""}
        end

        def innodb_option
          return ""
        end

        def change_engine (table_name, engine)
        end

        def add_fulltext_index (table_name, column)
          execute "CREATE INDEX #{table_name}_#{column}_idx on #{table_name} (#{column})"
        end

        def enumerations
          @enumerations ||= Hash.new
        end

        def create_enumeration(enumeration_name, values)
          enumerations[enumeration_name] = values
          execute "CREATE TYPE #{enumeration_name} AS ENUM ('#{values.join '\',\''}')"
        end

        def drop_enumeration(enumeration_name)
          execute "DROP TYPE #{enumeration_name}"
          enumerations.delete(enumeration_name)
        end

        def rename_enumeration(old_name, new_name)
          execute "ALTER TYPE #{quote_table_name(old_name)} RENAME TO #{quote_table_name(new_name)}"
        end

        def alter_primary_key(table_name, new_columns)
          execute "ALTER TABLE #{table_name} DROP CONSTRAINT #{table_name}_pkey"
          execute "ALTER TABLE #{table_name} ADD PRIMARY KEY (#{new_columns.join(',')})"
        end

        def interval_constant(interval)
          "'#{interval}'::interval"
        end

        def add_index(table_name, column_name, options = {})
          column_names = Array(column_name)
          index_name   = index_name(table_name, :column => column_names)

          if Hash === options # legacy support, since this param was a string
            index_type = options[:unique] ? "UNIQUE" : ""
            index_name = options[:name] || index_name
            index_method = options[:method] || "BTREE"
          else
            index_type = options
          end

          quoted_column_names = column_names.map { |e| quote_column_name(e) }
          if Hash === options and options[:lowercase]
            quoted_column_names = quoted_column_names.map { |e| "LOWER(#{e})" }
          end
          quoted_column_names = quoted_column_names.join(", ")

          execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} USING #{index_method} (#{quoted_column_names})"
        end
      end

      def rename_index(table_name, old_name, new_name)
        execute "ALTER INDEX #{quote_table_name(old_name)} RENAME TO #{quote_table_name(new_name)}"
      end

      def rename_sequence(table_name, old_name, new_name)
        execute "ALTER SEQUENCE #{quote_table_name(old_name)} RENAME TO #{quote_table_name(new_name)}"
      end
    end
  end
end