require 'apartment/tenant'

module Apartment
  module Migrator

    extend self

    # Migrate to latest
    def migrate(database)
      Tenant.switch(database) do
        version = ENV["VERSION"] ? ENV["VERSION"].to_i : nil

        migration_scope_block = -> (migration) { ENV["SCOPE"].blank? || (ENV["SCOPE"] == migration.scope) }

        if activerecord_below_5_2?
          ActiveRecord::Migrator.migrate(ActiveRecord::Migrator.migrations_paths, version, &migration_scope_block)
        else
          ActiveRecord::Base.connection.migration_context.migrate(version, &migration_scope_block)
        end
      end
    end

    # Migrate up/down to a specific version
    def run(direction, database, version)
      Tenant.switch(database) do
        if activerecord_below_5_2?
          ActiveRecord::Migrator.run(direction, ActiveRecord::Migrator.migrations_paths, version)
        else
          ActiveRecord::Base.connection.migration_context.run(direction, version)
        end
      end
    end

    # rollback latest migration `step` number of times
    def rollback(database, step = 1)
      Tenant.switch(database) do
        if activerecord_below_5_2?
          ActiveRecord::Migrator.rollback(ActiveRecord::Migrator.migrations_paths, step)
        else
          ActiveRecord::Base.connection.migration_context.rollback(step)
        end
      end
    end

    private

    def activerecord_below_5_2?
      ActiveRecord.version.release < Gem::Version.new('5.2.0')
    end
  end
end