require "cases/helper"

module ActiveRecord
  class InvertibleMigrationTest < ActiveRecord::TestCase
    class SilentMigration < ActiveRecord::Migration
      def write(text = '')
        # sssshhhhh!!
      end
    end

    class InvertibleMigration < SilentMigration
      def change
        create_table("horses") do |t|
          t.column :content, :text
          t.column :remind_at, :datetime
        end
      end
    end

    class InvertibleRevertMigration < SilentMigration
      def change
        revert do
          create_table("horses") do |t|
            t.column :content, :text
            t.column :remind_at, :datetime
          end
        end
      end
    end

    class NonInvertibleMigration < SilentMigration
      def change
        create_table("horses") do |t|
          t.column :content, :text
          t.column :remind_at, :datetime
        end
        remove_column "horses", :content
      end
    end

    class LegacyMigration < ActiveRecord::Migration
      def self.up
        create_table("horses") do |t|
          t.column :content, :text
          t.column :remind_at, :datetime
        end
      end

      def self.down
        drop_table("horses")
      end
    end

    class RevertWholeMigration < SilentMigration
      def initialize(name = self.class.name, version = nil, migration)
        @migration = migration
        super(name, version)
      end

      def change
        revert @migration
      end
    end

    class NestedRevertWholeMigration < RevertWholeMigration
      def change
        revert { super }
      end
    end

    def teardown
      if ActiveRecord::Base.connection.table_exists?("horses")
        ActiveRecord::Base.connection.drop_table("horses")
      end
    end

    def test_no_reverse
      migration = NonInvertibleMigration.new
      migration.migrate(:up)
      assert_raises(IrreversibleMigration) do
        migration.migrate(:down)
      end
    end

    def test_migrate_up
      migration = InvertibleMigration.new
      migration.migrate(:up)
      assert migration.connection.table_exists?("horses"), "horses should exist"
    end

    def test_migrate_down
      migration = InvertibleMigration.new
      migration.migrate :up
      migration.migrate :down
      assert !migration.connection.table_exists?("horses")
    end

    def test_migrate_revert
      migration = InvertibleMigration.new
      revert = InvertibleRevertMigration.new
      migration.migrate :up
      revert.migrate :up
      assert !migration.connection.table_exists?("horses")
      revert.migrate :down
      assert migration.connection.table_exists?("horses")
      migration.migrate :down
      assert !migration.connection.table_exists?("horses")
    end

    def test_migrate_revert_whole_migration
      migration = InvertibleMigration.new
      [LegacyMigration, InvertibleMigration].each do |klass|
        revert = RevertWholeMigration.new(klass)
        migration.migrate :up
        revert.migrate :up
        assert !migration.connection.table_exists?("horses")
        revert.migrate :down
        assert migration.connection.table_exists?("horses")
        migration.migrate :down
        assert !migration.connection.table_exists?("horses")
      end
    end

    def test_migrate_nested_revert_whole_migration
      revert = NestedRevertWholeMigration.new(InvertibleRevertMigration)
      revert.migrate :down
      assert revert.connection.table_exists?("horses")
      revert.migrate :up
      assert !revert.connection.table_exists?("horses")
    end

    def test_revert_order
      block = Proc.new{|t| t.string :name }
      recorder = ActiveRecord::Migration::CommandRecorder.new(ActiveRecord::Base.connection)
      recorder.instance_eval do
        create_table("apples", &block)
        revert do
          create_table("bananas", &block)
          revert do
            create_table("clementines")
            create_table("dates")
          end
          create_table("elderberries")
        end
        revert do
          create_table("figs")
          create_table("grapes")
        end
      end
      assert_equal [[:create_table, ["apples"], block], [:drop_table, ["elderberries"]],
                    [:create_table, ["clementines"], nil], [:create_table, ["dates"], nil],
                    [:drop_table, ["bananas"]], [:drop_table, ["grapes"]],
                    [:drop_table, ["figs"]]], recorder.commands
    end

    def test_legacy_up
      LegacyMigration.migrate :up
      assert ActiveRecord::Base.connection.table_exists?("horses"), "horses should exist"
    end

    def test_legacy_down
      LegacyMigration.migrate :up
      LegacyMigration.migrate :down
      assert !ActiveRecord::Base.connection.table_exists?("horses"), "horses should not exist"
    end

    def test_up
      LegacyMigration.up
      assert ActiveRecord::Base.connection.table_exists?("horses"), "horses should exist"
    end

    def test_down
      LegacyMigration.up
      LegacyMigration.down
      assert !ActiveRecord::Base.connection.table_exists?("horses"), "horses should not exist"
    end

    def test_migrate_down_with_table_name_prefix
      ActiveRecord::Base.table_name_prefix = 'p_'
      ActiveRecord::Base.table_name_suffix = '_s'
      migration = InvertibleMigration.new
      migration.migrate(:up)
      assert_nothing_raised { migration.migrate(:down) }
      assert !ActiveRecord::Base.connection.table_exists?("p_horses_s"), "p_horses_s should not exist"
    ensure
      ActiveRecord::Base.table_name_prefix = ActiveRecord::Base.table_name_suffix = ''
    end

  end
end