require 'yaml'
require 'pathname'

Capistrano::Configuration.instance.load do
  #
  # Capistrano sync.rb task for syncing databases and directories between the
  # local development environment and different multi_stage environments. You
  # cannot sync directly between two multi_stage environments, always use your
  # local machine as loop way.
  #
  # Author: Michael Kessler aka netzpirat
  # Gist:   111597
  #
  # Released under the MIT license.
  # Kindly sponsored by Screen Concept, www.screenconcept.ch
  #
  namespace :sync do

    after "deploy:setup", "sync:setup"

    desc <<-DESC
      Creates the sync dir in shared path. The sync directory is used to keep
      backups of database dumps and archives from synced directories. This task will
      be called on 'deploy:setup'
    DESC
    task :setup do
      run "mkdir -p #{shared_path}/sync"
    end

    namespace :down do

      desc <<-DESC
        Syncs the database and declared directories from the selected multi_stage environment
        to the local development environment. This task simply calls both the 'sync:down:db' and
        'sync:down:fs' tasks.
      DESC
      task :default do
        db and fs
      end

      desc <<-DESC
        Syncs database from the selected mutli_stage environement to the local develoment environment.
        The database credentials will be read from your local config/database.yml file and a copy of the
        dump will be kept within the shared sync directory. The amount of backups that will be kept is
        declared in the sync_backups variable and defaults to 5.
      DESC
      task :db, :roles => :db, :only => { :primary => true } do
        # Use production on non-multistage
        set :stage, 'production' unless exists?(:stage)

        filename = "database.#{stage}.#{Time.now.strftime '%Y-%m-%d_%H:%M:%S'}.sql.bz2"
        on_rollback { delete "#{shared_path}/sync/#{filename}" }

        # Remote DB dump
        username, password, database, host = remote_database_config(stage)
        host_option = host ? "--host='#{host}'" : ""
        run "mysqldump -u #{username} --password='#{password}' #{host_option} #{database} | bzip2 -9 > #{shared_path}/sync/#{filename}" do |channel, stream, data|
          puts data
        end
        purge_old_backups "database"

        # Download dump
        download "#{shared_path}/sync/#{filename}", filename

        # Local DB import
        username, password, database, host = database_config('development')
        system "bzip2 -d -c #{filename} | mysql -u #{username} --password='#{password}' #{database}; rm -f #{filename}"

        logger.important "sync database from the stage '#{stage}' to local finished"
        
        # Start db:migrate
        system "rake db:migrate"
      end

      desc <<-DESC
        Sync declared directories from the selected multi_stage environment to the local development
        environment. The synced directories must be declared as an array of Strings with the sync_directories
        variable. The path is relative to the rails root.
      DESC
      task :fs, :roles => :web, :once => true do
        # Use production on non-multistage
        set :stage, 'production' unless exists?(:stage)

        server, port = host_and_port

        Array(fetch(:sync_directories, [])).each do |syncdir|
          unless File.directory? "#{syncdir}"
            logger.info "create local '#{syncdir}' folder"
            Dir.mkdir "#{syncdir}"
          end
          logger.info "sync #{syncdir} from #{server}:#{port} to local"
          destination, base = Pathname.new(syncdir).split
          system "rsync --verbose --archive --compress --copy-links --delete --stats --rsh='ssh -p #{port}' #{user}@#{server}:#{current_path}/#{syncdir} #{destination.to_s}"
        end

        logger.important "sync filesystem from the stage '#{stage}' to local finished"
      end

      namespace :kuhsaft do

        desc <<-DESC
          Syncs the database and declared directories from the selected multi_stage environment
          to the local development environment. This task simply calls both the 'sync:down:kuhsaft:db' and
          'sync:down:kuhsaft:fs' tasks.
        DESC
        task :default do
          db
        end

        desc <<-DESC
          Syncs database from the selected mutli_stage environement to the local develoment environment.
          The database credentials will be read from your local config/database.yml file and a copy of the
          dump will be kept within the shared sync directory. The amount of backups that will be kept is
          declared in the sync_backups variable and defaults to 5.
        DESC
        task :db, :roles => :db, :only => { :primary => true } do
          # Use production on non-multistage
          set :stage, 'production' unless exists?(:stage)

          filename = "database.kuhsaft.#{stage}.#{Time.now.strftime '%Y-%m-%d_%H:%M:%S'}.sql.bz2"
          on_rollback { delete "#{shared_path}/sync/#{filename}" }

          # Remote DB dump
          username, password, database, host = remote_database_config(stage)
          host_option = host ? "--host='#{host}'" : ""
          run "mysqldump -u #{username} --password='#{password}' #{host_option} #{database} pages localized_pages contents assets tags taggings | bzip2 -9 > #{shared_path}/sync/#{filename}" do |channel, stream, data|
            puts data
          end
          purge_old_backups "database"

          # Download dump
          download "#{shared_path}/sync/#{filename}", filename

          # Local DB import
          username, password, database, host = database_config('development')
          system "bzip2 -d -c #{filename} | mysql -u #{username} --password='#{password}' #{database}; rm -f #{filename}"

          logger.important "sync database from the stage '#{stage}' to local finished"
        end
      end
    end

    namespace :up do

      desc <<-DESC
        Syncs the database and declared directories from the local development environment
        to the selected multi_stage environment. This task simply calls both the 'sync:up:db' and
        'sync:up:fs' tasks.
      DESC
      task :default do
        db and fs
      end

      desc <<-DESC
        Syncs database from the local develoment environment to the selected mutli_stage environement.
        The database credentials will be read from your local config/database.yml file and a copy of the
        dump will be kept within the shared sync directory. The amount of backups that will be kept is
        declared in the sync_backups variable and defaults to 5.
      DESC
      task :db, :roles => :db, :only => { :primary => true } do
        # Use production on non-multistage
        set :stage, 'production' unless exists?(:stage)

        filename = "database.all.#{stage}.#{Time.now.strftime '%Y-%m-%d_%H:%M:%S'}.sql.bz2"

        on_rollback do
          delete "#{shared_path}/sync/#{filename}"
          system "rm -f #{filename}"
        end

        # Make a backup before importing
        username, password, database, host = remote_database_config(stage)
        host_option = host ? "--host='#{host}'" : ""
        run "mysqldump -u #{username} --password='#{password}' #{host_option} #{database} | bzip2 -9 > #{shared_path}/sync/#{filename}" do |channel, stream, data|
          puts data
        end

        # Local DB export
        filename = "dump.local.#{Time.now.strftime '%Y-%m-%d_%H:%M:%S'}.sql.bz2"
        username, password, database, host = database_config('development')
        host_option = host ? "--host='#{host}'" : ""
        system "mysqldump -u #{username} --password='#{password}' #{host_option} #{database} | bzip2 -9 > #{filename}"
        upload filename, "#{shared_path}/sync/#{filename}"
        system "rm -f #{filename}"

        # Remote DB import
        username, password, database, host = remote_database_config(stage)
        host_option = host ? "--host='#{host}'" : ""
        run "bzip2 -d -c #{shared_path}/sync/#{filename} | mysql -u #{username} --password='#{password}' #{host_option} #{database}; rm -f #{shared_path}/sync/#{filename}"
        purge_old_backups "database.all"

        logger.important "sync database from local to the stage '#{stage}' finished"
      end

      desc <<-DESC
        Sync declared directories from the local development environement to the selected multi_stage
        environment. The synced directories must be declared as an array of Strings with the sync_directories
        variable.  The path is relative to the rails root.
      DESC
      task :fs, :roles => :web, :once => true do
        # Use production on non-multistage
        set :stage, 'production' unless exists?(:stage)

        server, port = host_and_port
        Array(fetch(:sync_directories, [])).each do |syncdir|
          destination, base = Pathname.new(syncdir).split
          if File.directory? "#{syncdir}"
            # Make a backup
            logger.info "backup #{syncdir}"
            run "tar cjf #{shared_path}/sync/#{base}.#{Time.now.strftime '%Y-%m-%d_%H:%M:%S'}.tar.bz2 #{current_path}/#{syncdir}"
            purge_old_backups "#{base}"
          else
            logger.info "Create '#{syncdir}' directory"
            run "mkdir #{current_path}/#{syncdir}"
          end

          # Sync directory up
          logger.info "sync #{syncdir} to #{server}:#{port} from local"
          system "rsync --verbose --archive --compress --keep-dirlinks --delete --stats --rsh='ssh -p #{port}' #{syncdir} #{user}@#{server}:#{current_path}/#{destination.to_s}"
        end
        logger.important "sync filesystem from local to the stage '#{stage}' finished"
      end

      namespace :kuhsaft do

        desc <<-DESC
          Syncs the database and declared directories from the local development environment
          to the selected multi_stage environment. This task simply calls both the 'sync:up:kuhsaft:db' task.
        DESC
        task :default do
          db
        end

        desc <<-DESC
          Syncs database from the local develoment environment to the selected mutli_stage environement.
          The database credentials will be read from your local config/database.yml file and a copy of the
          dump will be kept within the shared sync directory. The amount of backups that will be kept is
          declared in the sync_backups variable and defaults to 5.
        DESC
        task :db, :roles => :db, :only => { :primary => true } do
          # Use production on non-multistage
          set :stage, 'production' unless exists?(:stage)

          filename = "database.kuhsaft.#{stage}.#{Time.now.strftime '%Y-%m-%d_%H:%M:%S'}.sql.bz2"

          on_rollback do
            delete "#{shared_path}/sync/#{filename}"
            system "rm -f #{filename}"
          end

          # Make a backup before importing
          username, password, database, host = remote_database_config(stage)
          host_option = host ? "--host='#{host}'" : ""
          run "mysqldump -u #{username} --password='#{password}' #{host_option} #{database} pages localized_pages contents assets tags taggings | bzip2 -9 > #{shared_path}/sync/#{filename}" do |channel, stream, data|
            puts data
          end

          # Local DB export
          filename = "dump.local.#{Time.now.strftime '%Y-%m-%d_%H:%M:%S'}.sql.bz2"
          username, password, database, host = database_config('development')
          host_option = host ? "--host='#{host}'" : ""
          system "mysqldump -u #{username} --password='#{password}' #{host_option} #{database} | bzip2 -9 > #{filename}"
          upload filename, "#{shared_path}/sync/#{filename}"
          system "rm -f #{filename}"

          # Remote DB import
          username, password, database, host = remote_database_config(stage)
          host_option = host ? "--host='#{host}'" : ""
          run "bzip2 -d -c #{shared_path}/sync/#{filename} | mysql -u #{username} --password='#{password}' #{host_option} #{database}; rm -f #{shared_path}/sync/#{filename}"
          purge_old_backups "database.kuhsaft"

          logger.important "sync database from local to the stage '#{stage}' finished"
        end
      end

    end

    #
    # Reads the database credentials from the local config/database.yml file
    # +db+ the name of the environment to get the credentials for
    # Returns username, password, database
    #
    def database_config(db)
      database = YAML::load_file('config/database.yml')
      return database["#{db}"]['username'], database["#{db}"]['password'], database["#{db}"]['database'], database["#{db}"]['host']
    end

    #
    # Reads the database credentials from the remote config/database.yml file
    # +db+ the name of the environment to get the credentials for
    # Returns username, password, database
    #
    def remote_database_config(db)
      env = rails_env || db
      config = capture "cat #{deploy_to}/current/config/database.yml"
      database = YAML::load(config)
      return database["#{env}"]['username'], database["#{env}"]['password'], database["#{env}"]['database'], database["#{env}"]['host']
    end

    #
    # Returns the actual host name to sync and port
    #
    def host_and_port
      return roles[:web].servers.first.host, ssh_options[:port] || roles[:web].servers.first.port || 22
    end

    #
    # Purge old backups within the shared sync directory
    #
    def purge_old_backups(base)
      count = fetch(:sync_backups, 5).to_i
      backup_files = capture("ls -xt #{shared_path}/sync/#{base}*").split.reverse
      if count >= backup_files.length
        logger.important "no old backups to clean up"
      else
        logger.info "keeping #{count} of #{backup_files.length} sync backups"
        delete_backups = (backup_files - backup_files.last(count)).join(" ")
        try_sudo "rm -rf #{delete_backups}"
      end
    end

  end
end