# -*- encoding : utf-8 -*-

class Card::Migration < ActiveRecord::Migration
  include Card::ActiveRecordHelper
  @type = :deck_cards

  class << self
    # Rake tasks use class methods, migrations use instance methods.
    # To avoid repetition a lot of instance methods here just call class
    # methods.
    # The subclass Card::CoreMigration needs a different @type so we can't use a
    # class variable @@type. It has to be a class instance variable.
    # Migrations are subclasses of Card::Migration or Card::CoreMigration
    # but they don't inherit the @type. The method below solves this problem.
    def type
      @type || (ancestors[1] && ancestors[1].type)
    end

    def find_unused_name base_name
      test_name = base_name
      add = 1
      while Card.exists?(test_name)
        test_name = "#{base_name}#{add}"
        add += 1
      end
      test_name
    end

    def migration_paths mig_type=type
      Cardio.migration_paths mig_type
    end

    def schema mig_type=type
      Cardio.schema mig_type
    end

    def schema_suffix mig_type=type
      Cardio.schema_suffix mig_type
    end

    def schema_mode mig_type=type
      new_suffix = schema_suffix mig_type
      original_suffix = ActiveRecord::Base.table_name_suffix

      ActiveRecord::Base.table_name_suffix = new_suffix
      ActiveRecord::SchemaMigration.reset_table_name
      yield
      ActiveRecord::Base.table_name_suffix = original_suffix
      ActiveRecord::SchemaMigration.reset_table_name
    end

    def assume_migrated_upto_version
      schema_mode do
        ActiveRecord::Schema.assume_migrated_upto_version schema,
                                                          migration_paths
      end
    end

    def data_path filename=nil
      path = migration_paths.first
      File.join([path, 'data', filename].compact)
    end
  end

  def contentedly
    Card::Cache.reset_global
    Cardio.schema_mode '' do
      Card::Auth.as_bot do
        ActiveRecord::Base.transaction do
          begin
            yield
          ensure
            Card::Cache.reset_global
          end
        end
      end
    end
  end

  def import_json filename, merge_opts={}
    Card.config.action_mailer.perform_deliveries = false
    output_file = File.join data_path, "unmerged_#{ filename }"
    merge_opts[:output_file] ||= output_file
    Card.merge_list read_json(filename), merge_opts
  end

  def read_json filename
    raw_json = File.read data_path(filename)
    json = JSON.parse raw_json
    json['card']['value']
  end

  def data_path filename=nil
    self.class.data_path filename
  end

  def schema_mode
    Cardio.schema_mode self.class.type
  end

  def migration_paths
    Cardio.paths self.class.type
  end

  # Execute this migration in the named direction
  # copied from ActiveRecord to wrap 'up' in 'contentendly'
  def exec_migration conn, direction
    @connection = conn
    if respond_to?(:change)
      if direction == :down
        revert { change }
      else
        change
      end
    else
      contentedly { send(direction) }
    end
  ensure
    @connection = nil
  end

  def down
    raise ActiveRecord::IrreversibleMigration
  end
end

require 'card/core_migration'