namespace :shopapp do
  def deployment_settings
    target = ENV['target'] || 'production'
    Rails.configuration.settings['deployment']['default'].to_h.merge(
      Rails.configuration.settings['deployment'][target].to_h
    )
  end

  def deployment_targets
    Rails.configuration.settings['deployment'].to_h.keys - ['default']
  end

  def fetchdb(timestamp)
    user = deployment_settings['dbuser'] || deployment_settings['user']
    server = deployment_settings['dbserver'] || deployment_settings['server']
    db_name = deployment_settings['dbname'] || Rails.configuration.database_configuration['production']['database']
    dump_filename = "#{db_name}_#{timestamp}.dump"

    puts "Creating production db backup from #{db_name} to #{dump_filename}..."
    host_flag = if deployment_settings['dbhost'].present?
      "-h #{deployment_settings['dbhost']}"
    end
    system "ssh #{user}@#{server} 'pg_dump -Fc -c --no-owner #{host_flag} #{db_name} > #{dump_filename}'"
    mkdir_p Rails.root.join('tmp')
    puts "Copying to local..."
    system "scp #{user}@#{server}:#{dump_filename} #{Rails.root.join('tmp')}"
  end

  def restoredb(timestamp)
    db_name = deployment_settings['dbname'] || Rails.configuration.database_configuration['production']['database']
    dump_filename = "#{db_name}_#{timestamp}.dump"
    restoredb_from_file(dump_filename)
  end

  def restoredb_from_file(dump_filepath)
    dev_db_name = Rails.configuration.database_configuration['development']['database']
    puts "Restoring to local development database from #{dump_filepath}..."
    system "pg_restore --no-owner --verbose -c --no-acl -n public --dbname #{dev_db_name} #{Rails.root.join('tmp', dump_filepath)}"
    puts "Done restoring the database from #{dump_filepath} to local development."
  end

  desc 'list existing targets'
  task targets: :environment do
    puts deployment_targets.join(', ')
  end

  desc 'pull prod db to local dev'
  task pulldb: :environment do
    timestamp = Time.now.strftime('%Y%m%d%H%M%S')
    fetchdb(timestamp)
    restoredb(timestamp)
  end

  desc 'fetch prod db to local tmp folder'
  task fetchdb: :environment do
    timestamp = Time.now.strftime('%Y%m%d%H%M%S')
    fetchdb(timestamp)
  end

  desc 'execute command on production server'
  task run: :environment do
    ARGV.each { |a| task a.to_sym do ; end }
    user = deployment_settings['user']
    server = deployment_settings['server']

    deployment_folder_name = (deployment_settings['folder']) ||
                             "#{(Rails.configuration.settings['shopapp_name'] ||
                              Rails.application.class.parent_name).to_s.downcase.parameterize.underscore}/current"

    cmd = %(ssh -t #{user}@#{server} 'cd #{deployment_folder_name}; bash --login -c "#{ARGV[1..-1].join(' ')}"')
    exec cmd
  end

  desc "tails and follows target's log/production.log"
  task :tail do
    exec %(target=#{ENV['target']} rake shopapp:run "tail -f log/production.log")
  end

  desc "opens bash prompt on target"
  task :bash do
    exec %(target=#{ENV['target']} rake shopapp:run "/bin/bash")
  end

  desc "opens rails console on target"
  task :console do
    exec %(target=#{ENV['target']} rake shopapp:run "rails c")
  end

  desc "executes rake task(s) on target"
  task rake: :environment do
    exec %(target=#{ENV['target']} rake shopapp:run "rake #{ARGV[1]}")
  end

  desc 'help about these rakes tasks'
  task :help do
    puts case ENV['cmd']
          when 'console'
            'Opens rails console on the target. No parameters allowed.'
          when 'tail'
            'Tails main production log on target, until CTRL+C. No parameters allowed.'
          when 'bash'
            'Opens the bash terminal on target with application user in the deployment folder. No parameters allowed.'
          when 'run'
            'Executes on target in deployment directory under deployment user arbitrary command specified by parameters.'
          when 'rake'
            "Executes a rake task on target in deployment directory under deployment user.\n" +
            "First parameter is task name (possiblly with namespace(s)), other parameters are passed to rake task."
          when 'pulldb'
            'Dumps target production database and restores it to local development db. No parameters allowed.'
          when 'fetchdb'
            'Dumps target production database and copies it to local tmp folder.'
          when 'restoredb'
            "Restores database dump fetched with fetchdb from tmp folder.\n" +
            "Parameter is the database name without dump suffix). Default is the latest dump."
          when 'help'
            "Com'on, for real!"
          else
            "There is no command #{ENV['cmd']}"
          end
  end

  task restoredb: :environment do
    dump_filepath ||= if ENV['timestamp']
                        Rails.root.join "tmp/#{deployment_settings['dbname']}_#{ENV['timestamp']}.dump"
                      else
                        ENV['filepath'] ||
                          Dir[Rails.root.join("tmp/#{deployment_settings['dbname']}_*.dump")].sort.last
                      end
    restoredb_from_file(dump_filepath)
  end
end