def origin_branches
  `git branch -a`.
    split("\n").
    reject{|line| line =~ /HEAD/}.
    reject{|line| line =~ /master/}.
    select{|line| line =~ /remotes\/origin\//}.
    map{|line| line.sub(/.*remotes\/origin\//, '')}
end

def instance_deploy_tasks(prefix, instance, &block)
  namespace instance do
    namespace :deploy do
      origin_branches.each do |branch|
        desc "Deploy '#{prefix}_#{instance}' from branch '#{branch}'"
        task branch do
          set :revision, branch
          set :deploy_to, "/opt/www/#{prefix}_#{instance}"
          set :instance, instance
          set :prefix, prefix
          deploy do
            block.call(prefix, instance)
          end
          invoke :__stop
          queue 'sleep 5'
          invoke :__start
          invoke 'deploy:cleanup'
        end
      end
    end

    desc "Deploy '#{prefix}_#{instance}' from master"
    task :deploy do
      set :revision, 'master'
      set :deploy_to, "/opt/www/#{prefix}_#{instance}"
      set :instance, instance
      set :prefix, prefix
      deploy do
        block.call(prefix, instance)
      end
      invoke :__stop
      queue 'sleep 5'
      invoke :__start
      invoke 'deploy:cleanup'
    end
  end
end

def instance_setup_task(prefix, instance)
  namespace instance do
    desc "Setup '#{prefix}_#{instance}'"
    task :setup do
      set :revision, 'master'
      set :deploy_to, "/opt/www/#{prefix}_#{instance}"
      set :instance, instance
      set :prefix, prefix
      invoke :setup
    end
  end
end

def instance_manage_tasks(prefix, instance)
  namespace instance do
    desc "Start '#{prefix}_#{instance}'"
    task :start do
      set :deploy_to, "/opt/www/#{prefix}_#{instance}"
      set :instance, instance
      set :prefix, prefix
      invoke :__start
    end

    desc "Restart '#{prefix}_#{instance}'"
    task :restart do
      set :deploy_to, "/opt/www/#{prefix}_#{instance}"
      set :instance, instance
      set :prefix, prefix
      invoke :__stop
      queue 'sleep 5'
      invoke :__start
    end

    desc "Stop '#{prefix}_#{instance}'"
    task :stop do
      set :deploy_to, "/opt/www/#{prefix}_#{instance}"
      set :instance, instance
      set :prefix, prefix
      invoke :__stop
    end

    desc "Tail Log '#{prefix}_#{instance}'"
    task :log do
      set :deploy_to, "/opt/www/#{prefix}_#{instance}"
      set :instance, instance
      set :prefix, prefix
      invoke :__log
    end
  end
end

task :__git_clone do
  queue %{
    echo "-----> Cloning the Git repository"
    #{echo_cmd %[git clone "#{repository!}" .]}
  }

  if revision != 'master'
    queue %{
      echo "-----> Using revision #{revision}" &&
      #{echo_cmd %[git checkout "#{revision}"]}
    }
  end
end

task :__start do
  queue %{
    cd #{deploy_to}/current && bundle exec unicorn_rails -c /opt/unicorn-conf/#{prefix}_#{instance}.rb -E production -D &&
    echo "-----> #{instance} Started"
  }
end

task :__stop do
  queue %{
    kill -QUIT `cat /opt/unicorn-pids/#{prefix}_#{instance}.pid`; true
    echo "----->  #{instance} Stopped"
  }
end

task :__log do
  queue %{
    cd #{deploy_to}/current && tail -400 log/production.log
  }
end