module API
  # Build Trigger API
  class Triggers < Grape::API
    resource :projects do
      # Trigger a GitLab CI project build
      #
      # Parameters:
      #   id (required) - The ID of a CI project
      #   ref (required) - The name of project's branch or tag
      #   token (required) - The uniq token of trigger
      # Example Request:
      #   POST /projects/:id/ref/:ref/trigger
      post ":id/refs/:ref/trigger" do
        required_attributes! [:token]

        project = Project.find(params[:id])
        trigger = Trigger.find_by_token(params[:token].to_s)
        not_found! unless project && trigger
        unauthorized! unless trigger.project == project

        # validate variables
        variables = params[:variables]
        if variables
          unless variables.is_a?(Hash)
            render_api_error!('variables needs to be a hash', 400)
          end

          unless variables.all? { |key, value| key.is_a?(String) && value.is_a?(String) }
            render_api_error!('variables needs to be a map of key-valued strings', 400)
          end

          # convert variables from Mash to Hash
          variables = variables.to_h
        end

        # create request and trigger builds
        trigger_request = CreateTriggerRequestService.new.execute(project, trigger, params[:ref].to_s, variables)
        if trigger_request
          present trigger_request, with: Entities::TriggerRequest
        else
          errors = 'No builds created'
          render_api_error!(errors, 400)
        end
      end
    end
  end
end
