Overwrite Rails 3 databases rake task to remove method pollution on Object

databases.rake

# The built-in Rails database rake task is completely crazy, and defines methods on Object. This causes
# problems with Makara, which uses a delegator pattern along with method_missing.

require 'active_support/core_ext/object/inclusion'
require 'active_record'

class Object
  remove_method :configs_for_environment
  remove_method :create_database
  remove_method :current_config
  remove_method :database_url_config
  remove_method :drop_database_and_rescue
  remove_method :drop_database
  remove_method :firebird_db_string
  remove_method :mysql_creation_options
  remove_method :session_table_name
  remove_method :set_firebird_env
  remove_method :set_psql_env
end

Rake::TaskManager.class_eval do
  def remove_task(task_name)
    @tasks.delete(task_name.to_s)
  end
end

Rake.application.remove_task('db:load_config')
Rake.application.remove_task('db:create:all')
Rake.application.remove_task('db:create')
Rake.application.remove_task('db:drop:all')
Rake.application.remove_task('db:drop')
Rake.application.remove_task('db:migrate')
Rake.application.remove_task('db:_dump')
Rake.application.remove_task('db:migrate:redo')
Rake.application.remove_task('db:migrate:reset')
Rake.application.remove_task('db:migrate:up')
Rake.application.remove_task('db:migrate:down')
Rake.application.remove_task('db:migrate:status')
Rake.application.remove_task('db:rollback')
Rake.application.remove_task('db:forward')
Rake.application.remove_task('db:reset')
Rake.application.remove_task('db:charset')
Rake.application.remove_task('db:collation')
Rake.application.remove_task('db:version')
Rake.application.remove_task('db:abort_if_pending_migrations')
Rake.application.remove_task('db:setup')
Rake.application.remove_task('db:seed')
Rake.application.remove_task('db:fixtures:load')
Rake.application.remove_task('db:fixtures:identify')
Rake.application.remove_task('db:schema:dump')
Rake.application.remove_task('db:schema:load')
Rake.application.remove_task('db:schema:load_if_ruby')
Rake.application.remove_task('db:structure:dump')
Rake.application.remove_task('db:structure:load')
Rake.application.remove_task('db:structure:load_if_sql')
Rake.application.remove_task('db:test:load')
Rake.application.remove_task('db:test:load_structure')
Rake.application.remove_task('db:test:clone')
Rake.application.remove_task('db:test:clone_structure')
Rake.application.remove_task('db:test:purge')
Rake.application.remove_task('db:test:prepare')
Rake.application.remove_task('db:sessions:create')
Rake.application.remove_task('db:sessions:clear')
Rake.application.remove_task('railties:install:migrations')

require 'active_support/core_ext/string/filters'

module ActiveRecord
  module Tasks # :nodoc:
    class DatabaseAlreadyExists < StandardError; end # :nodoc:
    class DatabaseNotSupported < StandardError; end # :nodoc:

    class PostgreSQLDatabaseTasks # :nodoc:
      DEFAULT_ENCODING = ENV['CHARSET'] || 'utf8'

      delegate :connection, :establish_connection, :clear_active_connections!,
               to: ActiveRecord::Base

      def initialize(configuration)
        @configuration = configuration
      end

      def create(master_established = false)
        establish_master_connection unless master_established
        connection.create_database configuration['database'],
                                   configuration.merge('encoding' => encoding)
        establish_connection configuration
      rescue ActiveRecord::StatementInvalid => error
        if /database .* already exists/ === error.message
          raise DatabaseAlreadyExists
        else
          raise
        end
      end

      def drop
        establish_master_connection
        connection.drop_database configuration['database']
      end

      def charset
        connection.encoding
      end

      def collation
        connection.collation
      end

      def purge
        clear_active_connections!
        drop
        create true
      end

      def structure_dump(filename)
        set_psql_env

        search_path = case ActiveRecord::Base.dump_schemas
                        when :schema_search_path
                          configuration['schema_search_path']
                        when :all
                          nil
                        when String
                          ActiveRecord::Base.dump_schemas
                      end

        args = ['-i', '-s', '-x', '-O', '-f', filename]
        unless search_path.blank?
          args << search_path.split(',').map do |part|
            "--schema=#{part.strip}"
          end.join(' ')
        end
        args << configuration['database']
        run_cmd('pg_dump', args, 'dumping')
        File.open(filename, "a") { |f| f << "SET search_path TO #{connection.schema_search_path};\n\n" }
      end

      def structure_load(filename)
        set_psql_env
        args = ['-q', '-f', filename, configuration['database']]
        run_cmd('psql', args, 'loading')
      end

      private

      def configuration
        @configuration
      end

      def encoding
        configuration['encoding'] || DEFAULT_ENCODING
      end

      def establish_master_connection
        establish_connection configuration.merge(
                                 'database' => 'postgres',
                                 'schema_search_path' => 'public'
                             )
      end

      def set_psql_env
        ENV['PGHOST'] = configuration['host'] if configuration['host']
        ENV['PGPORT'] = configuration['port'].to_s if configuration['port']
        ENV['PGPASSWORD'] = configuration['password'].to_s if configuration['password']
        ENV['PGUSER'] = configuration['username'].to_s if configuration['username']
      end

      def run_cmd(cmd, args, action)
        fail run_cmd_error(cmd, args, action) unless Kernel.system(cmd, *args)
      end

      def run_cmd_error(cmd, args, action)
        msg = "failed to execute:\n"
        msg << "#{cmd} #{args.join(' ')}\n\n"
        msg << "Please check the output above for any errors and make sure that `#{cmd}` is installed in your PATH and has proper permissions.\n\n"
        msg
      end
    end

    # <tt>ActiveRecord::Tasks::DatabaseTasks</tt> is a utility class, which encapsulates
    # logic behind common tasks used to manage database and migrations.
    #
    # The tasks defined here are used with Rake tasks provided by Active Record.
    #
    # In order to use DatabaseTasks, a few config values need to be set. All the needed
    # config values are set by Rails already, so it's necessary to do it only if you
    # want to change the defaults or when you want to use Active Record outside of Rails
    # (in such case after configuring the database tasks, you can also use the rake tasks
    # defined in Active Record).
    #
    # The possible config values are:
    #
    #   * +env+: current environment (like Rails.env).
    #   * +database_configuration+: configuration of your databases (as in +config/database.yml+).
    #   * +db_dir+: your +db+ directory.
    #   * +fixtures_path+: a path to fixtures directory.
    #   * +migrations_paths+: a list of paths to directories with migrations.
    #   * +seed_loader+: an object which will load seeds, it needs to respond to the +load_seed+ method.
    #   * +root+: a path to the root of the application.
    #
    # Example usage of +DatabaseTasks+ outside Rails could look as such:
    #
    #   include ActiveRecord::Tasks
    #   DatabaseTasks.database_configuration = YAML.load_file('my_database_config.yml')
    #   DatabaseTasks.db_dir = 'db'
    #   # other settings...
    #
    #   DatabaseTasks.create_current('production')
    module DatabaseTasks
      extend self

      attr_writer :current_config, :db_dir, :migrations_paths, :fixtures_path, :root, :env, :seed_loader
      attr_accessor :database_configuration

      LOCAL_HOSTS = ['127.0.0.1', 'localhost']

      def register_task(pattern, task)
        @tasks ||= {}
        @tasks[pattern] = task
      end

      register_task(/postgresql/, ActiveRecord::Tasks::PostgreSQLDatabaseTasks)

      def db_dir
        @db_dir ||= Rails.application.config.paths["db"].first
      end

      def migrations_paths
        @migrations_paths ||= Rails.application.paths['db/migrate'].to_a
      end

      def fixtures_path
        @fixtures_path ||= if ENV['FIXTURES_PATH']
                             File.join(root, ENV['FIXTURES_PATH'])
                           else
                             File.join(root, 'test', 'fixtures')
                           end
      end

      def root
        @root ||= Rails.root
      end

      def env
        @env ||= Rails.env
      end

      def seed_loader
        @seed_loader ||= Rails.application
      end

      def current_config(options = {})
        options.reverse_merge! :env => env
        if options.has_key?(:config)
          @current_config = options[:config]
        else
          @current_config ||= ActiveRecord::Base.configurations[options[:env]]
        end
      end

      def create(*arguments)
        configuration = arguments.first
        class_for_adapter(configuration['adapter']).new(*arguments).create
      rescue DatabaseAlreadyExists
        $stderr.puts "#{configuration['database']} already exists"
      rescue Exception => error
        $stderr.puts error, *(error.backtrace)
        $stderr.puts "Couldn't create database for #{configuration.inspect}"
      end

      def create_all
        each_local_configuration { |configuration| create configuration }
      end

      def create_current(environment = env)
        each_current_configuration(environment) { |configuration|
          create configuration
        }
        ActiveRecord::Base.establish_connection(environment.to_sym)
      end

      def drop(*arguments)
        configuration = arguments.first
        class_for_adapter(configuration['adapter']).new(*arguments).drop
      rescue ActiveRecord::NoDatabaseError
        $stderr.puts "Database '#{configuration['database']}' does not exist"
      rescue Exception => error
        $stderr.puts error, *(error.backtrace)
        $stderr.puts "Couldn't drop #{configuration['database']}"
      end

      def drop_all
        each_local_configuration { |configuration| drop configuration }
      end

      def drop_current(environment = env)
        each_current_configuration(environment) { |configuration|
          drop configuration
        }
      end

      def migrate
        verbose = ENV["VERBOSE"] ? ENV["VERBOSE"] == "true" : true
        version = ENV["VERSION"] ? ENV["VERSION"].to_i : nil
        scope = ENV['SCOPE']
        verbose_was, Migration.verbose = Migration.verbose, verbose
        Migrator.migrate(Migrator.migrations_paths, version) do |migration|
          scope.blank? || scope == migration.scope
        end
      ensure
        Migration.verbose = verbose_was
      end

      def charset_current(environment = env)
        charset ActiveRecord::Base.configurations[environment]
      end

      def charset(*arguments)
        configuration = arguments.first
        class_for_adapter(configuration['adapter']).new(*arguments).charset
      end

      def collation_current(environment = env)
        collation ActiveRecord::Base.configurations[environment]
      end

      def collation(*arguments)
        configuration = arguments.first
        class_for_adapter(configuration['adapter']).new(*arguments).collation
      end

      def purge(configuration)
        class_for_adapter(configuration['adapter']).new(configuration).purge
      end

      def purge_all
        each_local_configuration { |configuration|
          purge configuration
        }
      end

      def purge_current(environment = env)
        each_current_configuration(environment) { |configuration|
          purge configuration
        }
        ActiveRecord::Base.establish_connection(environment.to_sym)
      end

      def structure_dump(*arguments)
        configuration = arguments.first
        filename = arguments.delete_at 1
        class_for_adapter(configuration['adapter']).new(*arguments).structure_dump(filename)
      end

      def structure_load(*arguments)
        configuration = arguments.first
        filename = arguments.delete_at 1
        class_for_adapter(configuration['adapter']).new(*arguments).structure_load(filename)
      end

      def load_schema(configuration, format = ActiveRecord::Base.schema_format, file = nil) # :nodoc:
        file ||= schema_file(format)

        case format
          when :ruby
            check_schema_file(file)
            ActiveRecord::Base.establish_connection(configuration)
            load(file)
          when :sql
            check_schema_file(file)
            structure_load(configuration, file)
          else
            raise ArgumentError, "unknown format #{format.inspect}"
        end
      end

      def load_schema_for(*args)
        ActiveSupport::Deprecation.warn(<<-MSG.squish)
          This method was renamed to `#load_schema` and will be removed in the future.
          Use `#load_schema` instead.
        MSG
        load_schema(*args)
      end

      def schema_file(format = ActiveRecord::Base.schema_format)
        case format
          when :ruby
            File.join(db_dir, "schema.rb")
          when :sql
            File.join(db_dir, "structure.sql")
        end
      end

      def load_schema_current_if_exists(format = ActiveRecord::Base.schema_format, file = nil, environment = env)
        if File.exist?(file || schema_file(format))
          load_schema_current(format, file, environment)
        end
      end

      def load_schema_current(format = ActiveRecord::Base.schema_format, file = nil, environment = env)
        each_current_configuration(environment) { |configuration|
          load_schema configuration, format, file
        }
        ActiveRecord::Base.establish_connection(environment.to_sym)
      end

      def check_schema_file(filename)
        unless File.exist?(filename)
          message = %{#{filename} doesn't exist yet. Run `rake db:migrate` to create it, then try again.}
          message << %{ If you do not intend to use a database, you should instead alter #{Rails.root}/config/application.rb to limit the frameworks that will be loaded.} if defined?(::Rails)
          Kernel.abort message
        end
      end

      def load_seed
        if seed_loader
          seed_loader.load_seed
        else
          raise "You tried to load seed data, but no seed loader is specified. Please specify seed " +
                    "loader with ActiveRecord::Tasks::DatabaseTasks.seed_loader = your_seed_loader\n" +
                    "Seed loader should respond to load_seed method"
        end
      end

      private

      def class_for_adapter(adapter)
        key = @tasks.keys.detect { |pattern| adapter[pattern] }
        unless key
          raise DatabaseNotSupported, "Rake tasks not supported by '#{adapter}' adapter"
        end
        @tasks[key]
      end

      def each_current_configuration(environment)
        environments = [environment]
        # add test environment only if no RAILS_ENV was specified.
        environments << 'test' if environment == 'development' && ENV['RAILS_ENV'].nil?

        configurations = ActiveRecord::Base.configurations.values_at(*environments)
        configurations.compact.each do |configuration|
          yield configuration unless configuration['database'].blank?
        end
      end

      def each_local_configuration
        ActiveRecord::Base.configurations.each_value do |configuration|
          next unless configuration['database']

          if local_database?(configuration)
            yield configuration
          else
            $stderr.puts "This task only modifies local databases. #{configuration['database']} is on a remote host."
          end
        end
      end

      def local_database?(configuration)
        configuration['host'].blank? || LOCAL_HOSTS.include?(configuration['host'])
      end
    end
  end
end

db_namespace = namespace :db do
  task :load_config do
    ActiveRecord::Base.configurations       = ActiveRecord::Tasks::DatabaseTasks.database_configuration ||
        YAML.load_file('config/database.yml') || {}
    ActiveRecord::Migrator.migrations_paths = ActiveRecord::Tasks::DatabaseTasks.migrations_paths
  end

  namespace :create do
    task :all => :load_config do
      ActiveRecord::Tasks::DatabaseTasks.create_all
    end
  end

  desc 'Creates the database from DATABASE_URL or config/database.yml for the current RAILS_ENV (use db:create:all to create all databases in the config). Without RAILS_ENV, it defaults to creating the development and test databases.'
  task :create => [:load_config] do
    ActiveRecord::Tasks::DatabaseTasks.create_current
  end

  namespace :drop do
    task :all => :load_config do
      ActiveRecord::Tasks::DatabaseTasks.drop_all
    end
  end

  desc 'Drops the database from DATABASE_URL or config/database.yml for the current RAILS_ENV (use db:drop:all to drop all databases in the config). Without RAILS_ENV, it defaults to dropping the development and test databases.'
  task :drop => [:load_config] do
    ActiveRecord::Tasks::DatabaseTasks.drop_current
  end

  namespace :purge do
    task :all => :load_config do
      ActiveRecord::Tasks::DatabaseTasks.purge_all
    end
  end

  # desc "Empty the database from DATABASE_URL or config/database.yml for the current RAILS_ENV (use db:drop:all to drop all databases in the config). Without RAILS_ENV it defaults to purging the development and test databases."
  task :purge => [:load_config] do
    ActiveRecord::Tasks::DatabaseTasks.purge_current
  end

  desc "Migrate the database (options: VERSION=x, VERBOSE=false, SCOPE=blog)."
  task :migrate => [:environment, :load_config] do
    ActiveRecord::Tasks::DatabaseTasks.migrate
    db_namespace['_dump'].invoke
  end

  # IMPORTANT: This task won't dump the schema if ActiveRecord::Base.dump_schema_after_migration is set to false
  task :_dump do
    # if ActiveRecord::Base.dump_schema_after_migration
    #   case ActiveRecord::Base.schema_format
    #   when :ruby then db_namespace["schema:dump"].invoke
    #   when :sql  then db_namespace["structure:dump"].invoke
    #   else
    #     raise "unknown schema format #{ActiveRecord::Base.schema_format}"
    #   end
    # end
    # Allow this task to be called as many times as required. An example is the
    # migrate:redo task, which calls other two internally that depend on this one.
    db_namespace["structure:dump"].invoke

    db_namespace['_dump'].reenable
  end

  namespace :migrate do
    # desc  'Rollbacks the database one migration and re migrate up (options: STEP=x, VERSION=x).'
    task :redo => [:environment, :load_config] do
      if ENV['VERSION']
        db_namespace['migrate:down'].invoke
        db_namespace['migrate:up'].invoke
      else
        db_namespace['rollback'].invoke
        db_namespace['migrate'].invoke
      end
    end

    # desc 'Resets your database using your migrations for the current environment'
    task :reset => ['db:drop', 'db:create', 'db:migrate']

    # desc 'Runs the "up" for a given migration VERSION.'
    task :up => [:environment, :load_config] do
      version = ENV['VERSION'] ? ENV['VERSION'].to_i : nil
      raise 'VERSION is required' unless version
      ActiveRecord::Migrator.run(:up, ActiveRecord::Migrator.migrations_paths, version)
      db_namespace['_dump'].invoke
    end

    # desc 'Runs the "down" for a given migration VERSION.'
    task :down => [:environment, :load_config] do
      version = ENV['VERSION'] ? ENV['VERSION'].to_i : nil
      raise 'VERSION is required - To go down one migration, run db:rollback' unless version
      ActiveRecord::Migrator.run(:down, ActiveRecord::Migrator.migrations_paths, version)
      db_namespace['_dump'].invoke
    end

    desc 'Display status of migrations'
    task :status => [:environment, :load_config] do
      unless ActiveRecord::SchemaMigration.table_exists?
        abort 'Schema migrations table does not exist yet.'
      end
      db_list = ActiveRecord::SchemaMigration.normalized_versions

      file_list =
          ActiveRecord::Migrator.migrations_paths.flat_map do |path|
            # match "20091231235959_some_name.rb" and "001_some_name.rb" pattern
            Dir.foreach(path).grep(/^(\d{3,})_(.+)\.rb$/) do
              version = ActiveRecord::SchemaMigration.normalize_migration_number($1)
              status = db_list.delete(version) ? 'up' : 'down'
              [status, version, $2.humanize]
            end
          end

      db_list.map! do |version|
        ['up', version, '********** NO FILE **********']
      end
      # output
      puts "\ndatabase: #{ActiveRecord::Base.connection_config[:database]}\n\n"
      puts "#{'Status'.center(8)}  #{'Migration ID'.ljust(14)}  Migration Name"
      puts "-" * 50
      (db_list + file_list).sort_by { |_, version, _| version }.each do |status, version, name|
        puts "#{status.center(8)}  #{version.ljust(14)}  #{name}"
      end
      puts
    end
  end

  desc 'Rolls the schema back to the previous version (specify steps w/ STEP=n).'
  task :rollback => [:environment, :load_config] do
    step = ENV['STEP'] ? ENV['STEP'].to_i : 1
    ActiveRecord::Migrator.rollback(ActiveRecord::Migrator.migrations_paths, step)
    db_namespace['_dump'].invoke
  end

  # desc 'Pushes the schema to the next version (specify steps w/ STEP=n).'
  task :forward => [:environment, :load_config] do
    step = ENV['STEP'] ? ENV['STEP'].to_i : 1
    ActiveRecord::Migrator.forward(ActiveRecord::Migrator.migrations_paths, step)
    db_namespace['_dump'].invoke
  end

  # desc 'Drops and recreates the database from db/schema.rb for the current environment and loads the seeds.'
  task :reset => [ 'db:drop', 'db:setup' ]

  # desc "Retrieves the charset for the current environment's database"
  task :charset => [:environment, :load_config] do
    puts ActiveRecord::Tasks::DatabaseTasks.charset_current
  end

  # desc "Retrieves the collation for the current environment's database"
  task :collation => [:environment, :load_config] do
    begin
      puts ActiveRecord::Tasks::DatabaseTasks.collation_current
    rescue NoMethodError
      $stderr.puts 'Sorry, your database adapter is not supported yet. Feel free to submit a patch.'
    end
  end

  desc 'Retrieves the current schema version number'
  task :version => [:environment, :load_config] do
    puts "Current version: #{ActiveRecord::Migrator.current_version}"
  end

  # desc "Raises an error if there are pending migrations"
  task :abort_if_pending_migrations => [:environment, :load_config] do
    pending_migrations = ActiveRecord::Migrator.open(ActiveRecord::Migrator.migrations_paths).pending_migrations

    if pending_migrations.any?
      puts "You have #{pending_migrations.size} pending #{pending_migrations.size > 1 ? 'migrations:' : 'migration:'}"
      pending_migrations.each do |pending_migration|
        puts '  %4d %s' % [pending_migration.version, pending_migration.name]
      end
      abort %{Run `rake db:migrate` to update your database then try again.}
    end
  end

  desc 'Creates the database, loads the schema, and initializes with the seed data (use db:reset to also drop the database first)'
  task :setup => ['db:schema:load_if_ruby', 'db:structure:load_if_sql', :seed]

  desc 'Loads the seed data from db/seeds.rb'
  task :seed do
    db_namespace['abort_if_pending_migrations'].invoke
    ActiveRecord::Tasks::DatabaseTasks.load_seed
  end

  namespace :fixtures do
    desc "Loads fixtures into the current environment's database. Load specific fixtures using FIXTURES=x,y. Load from subdirectory in test/fixtures using FIXTURES_DIR=z. Specify an alternative path (eg. spec/fixtures) using FIXTURES_PATH=spec/fixtures."
    task :load => [:environment, :load_config] do
      require 'active_record/fixtures'

      base_dir = ActiveRecord::Tasks::DatabaseTasks.fixtures_path

      fixtures_dir = if ENV['FIXTURES_DIR']
                       File.join base_dir, ENV['FIXTURES_DIR']
                     else
                       base_dir
                     end

      fixture_files = if ENV['FIXTURES']
                        ENV['FIXTURES'].split(',')
                      else
                        # The use of String#[] here is to support namespaced fixtures
                        Dir["#{fixtures_dir}/**/*.yml"].map {|f| f[(fixtures_dir.size + 1)..-5] }
                      end

      ActiveRecord::FixtureSet.create_fixtures(fixtures_dir, fixture_files)
    end

    # desc "Search for a fixture given a LABEL or ID. Specify an alternative path (eg. spec/fixtures) using FIXTURES_PATH=spec/fixtures."
    task :identify => [:environment, :load_config] do
      require 'active_record/fixtures'

      label, id = ENV['LABEL'], ENV['ID']
      raise 'LABEL or ID required' if label.blank? && id.blank?

      puts %Q(The fixture ID for "#{label}" is #{ActiveRecord::FixtureSet.identify(label)}.) if label

      base_dir = ActiveRecord::Tasks::DatabaseTasks.fixtures_path

      Dir["#{base_dir}/**/*.yml"].each do |file|
        if data = YAML::load(ERB.new(IO.read(file)).result)
          data.each_key do |key|
            key_id = ActiveRecord::FixtureSet.identify(key)

            if key == label || key_id == id.to_i
              puts "#{file}: #{key} (#{key_id})"
            end
          end
        end
      end
    end
  end

  namespace :schema do
    desc 'Creates a db/schema.rb file that is portable against any DB supported by AR'
    task :dump => [:environment, :load_config] do
      require 'active_record/schema_dumper'
      filename = ENV['SCHEMA'] || File.join(ActiveRecord::Tasks::DatabaseTasks.db_dir, 'schema.rb')
      File.open(filename, "w:utf-8") do |file|
        ActiveRecord::SchemaDumper.dump(ActiveRecord::Base.connection, file)
      end
      db_namespace['schema:dump'].reenable
    end

    desc 'Loads a schema.rb file into the database'
    task :load => [:environment, :load_config] do
      ActiveRecord::Tasks::DatabaseTasks.load_schema_current(:ruby, ENV['SCHEMA'])
    end

    task :load_if_ruby => ['db:create', :environment] do
      db_namespace["schema:load"].invoke if ActiveRecord::Base.schema_format == :ruby
    end

    namespace :cache do
      desc 'Creates a db/schema_cache.dump file.'
      task :dump => [:environment, :load_config] do
        con = ActiveRecord::Base.connection
        filename = File.join(ActiveRecord::Tasks::DatabaseTasks.db_dir, "schema_cache.dump")

        con.schema_cache.clear!
        con.tables.each { |table| con.schema_cache.add(table) }
        open(filename, 'wb') { |f| f.write(Marshal.dump(con.schema_cache)) }
      end

      desc 'Clears a db/schema_cache.dump file.'
      task :clear => [:environment, :load_config] do
        filename = File.join(ActiveRecord::Tasks::DatabaseTasks.db_dir, "schema_cache.dump")
        FileUtils.rm(filename) if File.exist?(filename)
      end
    end

  end

  namespace :structure do

    def database_url_config
      @database_url_config ||=
          ActiveRecord::Base::ConnectionSpecification::Resolver.new(ENV["DATABASE_URL"], {}).spec.config.stringify_keys
    end

    def current_config(options = {})
      options = { :env => Rails.env }.merge! options

      if options[:config]
        @current_config = options[:config]
      else
        @current_config ||= if ENV['DATABASE_URL']
                              database_url_config
                            else
                              ActiveRecord::Base.configurations[options[:env]]
                            end
      end
    end

    def set_psql_env(config)
      ENV['PGHOST']     = config['host']          if config['host']
      ENV['PGPORT']     = config['port'].to_s     if config['port']
      ENV['PGPASSWORD'] = config['password'].to_s if config['password']
      ENV['PGUSER']     = config['username'].to_s if config['username']
    end

    desc 'Dumps the database structure to db/structure.sql. Specify another file with SCHEMA=db/my_structure.sql'
    task :dump => [:environment, :load_config] do
      next if %w(production demo staging).include?(Rails.env)

      config = current_config
      filename = ENV['DB_STRUCTURE'] || File.join(Rails.root, "db", "structure.sql")
      case config['adapter']
      when /mysql/, 'oci', 'oracle'
        ActiveRecord::Base.establish_connection(config)
        File.open(filename, "w:utf-8") { |f| f << ActiveRecord::Base.connection.structure_dump }
      when /postgresql/
        set_psql_env(config)
        search_path = config['schema_search_path']
        unless search_path.blank?
          search_path = search_path.split(",").map{|search_path_part| "--schema=#{Shellwords.escape(search_path_part.strip)}" }.join(" ")
        end
        `pg_dump -i -s -x -O -f #{Shellwords.escape(filename)} #{search_path} #{Shellwords.escape(config['database'])}`
        raise 'Error dumping database' if $?.exitstatus == 1
        File.open(filename, "a") { |f| f << "SET search_path TO #{ActiveRecord::Base.connection.schema_search_path};\n\n" }
      when /sqlite/
        dbfile = config['database']
        `sqlite3 #{dbfile} .schema > #{filename}`
      when 'sqlserver'
        `smoscript -s #{config['host']} -d #{config['database']} -u #{config['username']} -p #{config['password']} -f #{filename} -A -U`
      when "firebird"
        set_firebird_env(config)
        db_string = firebird_db_string(config)
        sh "isql -a #{db_string} > #{filename}"
      else
        raise "Task not supported by '#{config['adapter']}'"
      end

      if ActiveRecord::Base.connection.supports_migrations?
        File.open(filename, "a") { |f| f << ActiveRecord::Base.connection.dump_schema_information }
      end
      db_namespace['structure:dump'].reenable
    end

    desc "Recreates the databases from the structure.sql file"
    task :load => [:load_config] do
      ActiveRecord::Tasks::DatabaseTasks.load_schema_current(:sql, ENV['SCHEMA'])
    end

    task :load_if_sql => ['db:create', :environment] do
      db_namespace["structure:load"].invoke if ActiveRecord::Base.schema_format == :sql
    end
  end

  namespace :test do

    task :deprecated do
      Rake.application.top_level_tasks.grep(/^db:test:/).each do |task|
        $stderr.puts "WARNING: #{task} is deprecated. The Rails test helper now maintains " \
                     "your test schema automatically, see the release notes for details."
      end
    end

    # desc "Recreate the test database from the current schema"
    task :load => %w(db:test:purge) do
      case ActiveRecord::Base.schema_format
        when :ruby
          db_namespace["test:load_schema"].invoke
        when :sql
          db_namespace["test:load_structure"].invoke
      end
    end

    # desc "Recreate the test database from an existent schema.rb file"
    task :load_schema => %w(db:test:purge) do
      begin
        should_reconnect = ActiveRecord::Base.connection_pool.active_connection?
        ActiveRecord::Schema.verbose = false
        ActiveRecord::Tasks::DatabaseTasks.load_schema ActiveRecord::Base.configurations['test'], :ruby, ENV['SCHEMA']
      ensure
        if should_reconnect
          ActiveRecord::Base.establish_connection(ActiveRecord::Base.configurations[ActiveRecord::Tasks::DatabaseTasks.env])
        end
      end
    end

    # desc "Recreate the test database from an existent structure.sql file"
    task :load_structure => %w(db:test:purge) do
      ActiveRecord::Tasks::DatabaseTasks.load_schema ActiveRecord::Base.configurations['test'], :sql, ENV['SCHEMA']
    end

    # desc "Recreate the test database from a fresh schema"
    task :clone => %w(db:test:deprecated environment) do
      case ActiveRecord::Base.schema_format
        when :ruby
          db_namespace["test:clone_schema"].invoke
        when :sql
          db_namespace["test:clone_structure"].invoke
      end
    end

    # desc "Recreate the test database from a fresh schema.rb file"
    task :clone_schema => %w(db:test:deprecated db:schema:dump db:test:load_schema)

    # desc "Recreate the test database from a fresh structure.sql file"
    task :clone_structure => %w(db:test:deprecated db:structure:dump db:test:load_structure)

    # desc "Empty the test database"
    task :purge => %w(environment load_config) do
      ActiveRecord::Tasks::DatabaseTasks.purge ActiveRecord::Base.configurations['test']
    end

    # desc 'Check for pending migrations and load the test schema'
    task :prepare => %w(environment load_config) do
      unless ActiveRecord::Base.configurations.blank?
        db_namespace['test:load'].invoke
      end
    end
  end
end

namespace :railties do
  namespace :install do
    # desc "Copies missing migrations from Railties (e.g. engines). You can specify Railties to use with FROM=railtie1,railtie2"
    task :migrations => :'db:load_config' do
      to_load = ENV['FROM'].blank? ? :all : ENV['FROM'].split(",").map(&:strip)
      railties = {}
      Rails.application.migration_railties.each do |railtie|
        next unless to_load == :all || to_load.include?(railtie.railtie_name)

        if railtie.respond_to?(:paths) && (path = railtie.paths['db/migrate'].first)
          railties[railtie.railtie_name] = path
        end
      end

      on_skip = Proc.new do |name, migration|
        puts "NOTE: Migration #{migration.basename} from #{name} has been skipped. Migration with the same name already exists."
      end

      on_copy = Proc.new do |name, migration|
        puts "Copied migration #{migration.basename} from #{name}"
      end

      ActiveRecord::Migration.copy(ActiveRecord::Migrator.migrations_paths.first, railties,
                                    :on_skip => on_skip, :on_copy => on_copy)
    end
  end
end