module ChatMessage
  class MergeMessage < BaseMessage
    attr_reader :merge_request_iid
    attr_reader :source_branch
    attr_reader :target_branch
    attr_reader :state
    attr_reader :title

    def initialize(params)
      super

      @action = params[:object_attributes][:action]

      obj_attr = params[:object_attributes]
      obj_attr = HashWithIndifferentAccess.new(obj_attr)
      @merge_request_iid = obj_attr[:iid]
      @source_branch = obj_attr[:source_branch]
      @target_branch = obj_attr[:target_branch]
      @state = obj_attr[:state]
      @title = format_title(obj_attr[:title])
    end

    def attachments
      []
    end

    def activity
      {
        title: "Merge Request #{state} by #{user_name}",
        subtitle: "in #{project_link}",
        text: merge_request_link,
        image: user_avatar
      }
    end

    private

    def format_title(title)
      '*' + title.lines.first.chomp + '*'
    end

    def message
      merge_request_message
    end

    def project_link
      link(project_name, project_url)
    end

    def merge_request_message
      "#{user_name} #{state_or_action_text} #{merge_request_link} in #{project_link}: #{title}"
    end

    def merge_request_link
      link(merge_request_title, merge_request_url)
    end

    def merge_request_title
      "#{MergeRequest.reference_prefix}#{merge_request_iid} #{title}"
    end

    def merge_request_url
      "#{project_url}/merge_requests/#{merge_request_iid}"
    end

    def state_or_action_text
      @action == 'approved' ? @action : state
    end
  end
end
