gistfile1.txt

namespace :db do 
  desc 'Dumps your current schema and data from the database into a timestamped .sql dumpfile'
  task :dump => :environment do
    puts "Dumping schema and data from #{@data_reload_helper.db_name} to #{@data_reload_helper.dump_path}"
    # -c Includes the column names in the insert statement. Important when rails reorders your columns on different machines
    @data_reload_helper.mysqldump('--add-drop-table -c')
  end

  desc 'Dumps your current schema and data from the database into a timestamped, gzipped .sql dumpfile'
  task :dump_deflated => ['dump', 'dump:deflate']

  namespace :dump do
    desc 'Dumps your current data from the database into a timestamped .sql dumpfile'
    task :data => :environment do
      puts "Dumping data from #{@data_reload_helper.db_name} to #{@data_reload_helper.dump_path}"
      # -c Includes the column names in the insert statement. Important when rails reorders your columns on different machines
      # -n Drops the 'create db' portions of the dump file
      # -t Drops creation info from the dump
      @data_reload_helper.mysqldump('-n -t -c')
    end

    desc 'Dumps your current data from the database into a timestamped, gzipped .sql dumpfile'
    task :data_deflated => [:data, :deflate]

    desc "Gzip's your most recent dump"
    task :deflate => :environment do
      latest = @data_reload_helper.latest_dump_file_name
      compressed_latest = @data_reload_helper.gzipify(latest)

      if latest.nil?
        puts "No files to compress"
      elsif File.exists?(compressed_latest)
        puts "#{latest} already compressed to #{compressed_latest}"
      else
        puts "Compressing #{latest} to #{compressed_latest}"
        writer = Zlib::GzipWriter.open(compressed_latest)
        writer.write File.read(latest)
        writer.close
      end
    end
  end

  desc 'Reloads your database from dump file dump.out if it exists, and migrates up'
  task :reload => [:drop, :create] do
    @data_reload_helper.do_reload { |latest_file_name| @data_reload_helper.mysql("#{@data_reload_helper.db_name} < #{latest_file_name}") }
  end

  desc 'Reloads your database data from a dump file'
  task :reload_data => :environment do
    @data_reload_helper.do_reload { |latest_file_name| @data_reload_helper.mysql("#{@data_reload_helper.db_name} < #{latest_file_name}") }
  end
end

class DataReloadHelper
  def db; ActiveRecord::Base.configurations[RAILS_ENV] end

  def db_name; db["database"] end
  def db_user; db["username"] end
  def db_pass; db["password"] end

  def gzipify(name)
    "#{name}.gz"
  end

  # Get the file name as blah_dev_dump_YYYYMMDDHHMMSS
  def dump_path; File.join("db", "#{db_name}_dump_#{Time.now.strftime('%Y%m%d%H%M%S')}.sql"); end
  def compressed_dump_path; gzipify(dump_path); end
  def dump_query(path=nil, name_format=nil)
    path ||= 'db'
    name_format ||= "#{db_name}_dump"

    File.join(path, "#{name_format}*.sql")
  end

  def mysql(arg_string)
    system("mysql #{credential_args} #{arg_string}")
  end

  def mysqldump(options='')
    system("mysqldump #{db_name} #{options} #{credential_args} > #{dump_path}")
    dump_path
  end

  def credential_args
    "-u #{db_user} --password=#{db_pass}"
  end

  def latest_dump_file_name(path=nil, name_format=nil)
    Dir[dump_query(path, name_format)].sort.last
  end

  def do_reload(path=nil, file_name_format=nil, &block)
    latest = ENV['dump_file'] || latest_dump_file_name(path, file_name_format)
    unless latest.blank?
      puts "Reloading #{db_name} from #{latest}"
      block.call(latest)
    else
      puts "Dump file for #{db_name} not found at #{dump_query(path, file_name_format)}"
    end
  end

end

@data_reload_helper = DataReloadHelper.new