class ActiveRecord::Tasks::MySQLDatabaseTasks

def charset
  connection.charset
end

def collation
  connection.collation
end

def configuration
  @configuration
end

def configuration_without_database
  configuration.merge('database' => nil)
end

def create
  establish_connection configuration_without_database
  connection.create_database configuration['database'], creation_options
  establish_connection configuration
rescue ActiveRecord::StatementInvalid => error
  if /database exists/ === error.message
    raise DatabaseAlreadyExists
  else
    raise
  end
rescue error_class => error
  if error.respond_to?(:errno) && error.errno == ACCESS_DENIED_ERROR
    $stdout.print error.error
    establish_connection root_configuration_without_database
    connection.create_database configuration['database'], creation_options
    if configuration['username'] != 'root'
      connection.execute grant_statement.gsub(/\s+/, ' ').strip
    end
    establish_connection configuration
  else
    $stderr.puts "Couldn't create database for #{configuration.inspect}, #{creation_options.inspect}"
    $stderr.puts "(If you set the charset manually, make sure you have a matching collation)" if configuration['encoding']
  end
end

def creation_options
  Hash.new.tap do |options|
    options[:charset]     = configuration['encoding']   if configuration.include? 'encoding'
    options[:collation]   = configuration['collation']  if configuration.include? 'collation'
    # Set default charset only when collation isn't set.
    options[:charset]   ||= DEFAULT_CHARSET unless options[:collation]
    # Set default collation only when charset is also default.
    options[:collation] ||= DEFAULT_COLLATION if options[:charset] == DEFAULT_CHARSET
  end
end

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

def error_class
  if configuration['adapter'] =~ /jdbc/
    require 'active_record/railties/jdbcmysql_error'
    ArJdbcMySQL::Error
  elsif defined?(Mysql2)
    Mysql2::Error
  elsif defined?(Mysql)
    Mysql::Error
  else
    StandardError
  end
end

def grant_statement
  <<-SQL
ALL PRIVILEGES ON #{configuration['database']}.*
#{configuration['username']}'@'localhost'
FIED BY '#{configuration['password']}' WITH GRANT OPTION;
  SQL
end

def initialize(configuration)
  @configuration = configuration
end

def prepare_command_options(command)
  args = [command]
  args.concat(['--user', configuration['username']]) if configuration['username']
  args << "--password=#{configuration['password']}"  if configuration['password']
  args.concat(['--default-character-set', configuration['encoding']]) if configuration['encoding']
  configuration.slice('host', 'port', 'socket').each do |k, v|
    args.concat([ "--#{k}", v ]) if v
  end
  args
end

def purge
  establish_connection :test
  connection.recreate_database configuration['database'], creation_options
end

def root_configuration_without_database
  configuration_without_database.merge(
    'username' => 'root',
    'password' => root_password
  )
end

def root_password
  $stdout.print "Please provide the root password for your mysql installation\n>"
  $stdin.gets.strip
end

def structure_dump(filename)
  args = prepare_command_options('mysqldump')
  args.concat(["--result-file", "#{filename}"])
  args.concat(["--no-data"])
  args.concat(["#{configuration['database']}"])
  unless Kernel.system(*args)
    $stderr.puts "Could not dump the database structure. "\
                 "Make sure `mysqldump` is in your PATH and check the command output for warnings."
  end
end

def structure_load(filename)
  args = prepare_command_options('mysql')
  args.concat(['--execute', %{SET FOREIGN_KEY_CHECKS = 0; SOURCE #{filename}; SET FOREIGN_KEY_CHECKS = 1}])
  args.concat(["--database", "#{configuration['database']}"])
  Kernel.system(*args)
end