module Jarl
  class Application
    attr_reader :group, :name, :image, :volumes, :ports, :environment, :entrypoint, :command

    # Create Application object from application definition:
    #
    # app_name:
    #   image: blabla
    #   volumes:
    #     - /host/path:/container/path
    #   ports:
    #     - 1234:5678
    #   command: blabla
    #
    def initialize(group, name, params)
      @group = group
      @name = name
      @image = params['image'] || fail("Application '#{self}' has no 'image' defined")
      unless @image.is_a?(String)
        fail "Application '#{self}' has invalid 'image' definition, String is expected"
      end
      @volumes = params['volumes'] || []
      unless @volumes.is_a?(Array)
        fail "Application '#{self}' has invalid 'volumes' definition, Array is expected"
      end
      @ports = params['ports'] || []
      unless @ports.is_a?(Array)
        fail "Application '#{self}' has invalid 'ports' definition, Array is expected"
      end
      @environment = params['environment'] || {}
      unless @environment.is_a?(Hash)
        fail "Application '#{self}' has invalid 'environment' definition, Hash is expected"
      end
      @entrypoint = params['entrypoint']
      if @entrypoint && !@entrypoint.is_a?(String)
        fail "Application '#{self}' has invalid 'entrypoint' definition, String is expected"
      end
      @command = params['command']
      if @command && !@command.is_a?(String)
        fail "Application '#{self}' has invalid 'command' definition, String is expected"
      end
    end

    def full_name
      "#{group}.#{name}"
    end

    def image_is_a_path?
      image =~ /^[~\.\/]/
    end

    def running?
      running_container
    end

    def running_container
      Docker.containers_running.find { |c| c.name == full_name }
    end

    def start
      running_container.stop! if running?
      Docker.start(
        name: full_name,
        image: image_name,
        volumes: volumes,
        ports: ports,
        environment: environment,
        command: command
      )
    end

    def build
      fail 'Not a file based image' unless image_is_a_path?
      Docker::Image.new(image_name, image_path).build!
    end

    def image_name
      image_is_a_path? ? name : image
    end

    def image_path
      image_is_a_path? ? image : nil
    end

    def show_log(*_args)
      return unless running?
      begin
        IO.popen "docker logs -f #{running_container.id}", 'r' do |p|
          str = '<<< STARTED >>>'
          puts "#{esc_yellow full_name}: #{str}" while str = p.gets
        end
      rescue Interrupt
        #
      end
    end

    def to_s
      full_name
    end
  end # class Application
end # module Jarl