module API
  module V3
    class Issues < Grape::API
      include PaginationParams

      before { authenticate! }

      helpers do
        def find_issues(args = {})
          args = params.merge(args)

          args.delete(:id)
          args[:milestone_title] = args.delete(:milestone)

          match_all_labels = args.delete(:match_all_labels)
          labels = args.delete(:labels)
          args[:label_name] = labels if match_all_labels

          args[:search] = "#{Issue.reference_prefix}#{args.delete(:iid)}" if args.key?(:iid)

          issues = IssuesFinder.new(current_user, args).execute.inc_notes_with_associations

          if !match_all_labels && labels.present?
            issues = issues.includes(:labels).where('labels.title' => labels.split(','))
          end

          issues.reorder(args[:order_by] => args[:sort])
        end

        params :issues_params do
          optional :labels, type: String, desc: 'Comma-separated list of label names'
          optional :milestone, type: String, desc: 'Milestone title'
          optional :order_by, type: String, values: %w[created_at updated_at], default: 'created_at',
                              desc: 'Return issues ordered by `created_at` or `updated_at` fields.'
          optional :sort, type: String, values: %w[asc desc], default: 'desc',
                          desc: 'Return issues sorted in `asc` or `desc` order.'
          optional :milestone, type: String, desc: 'Return issues for a specific milestone'
          use :pagination
        end

        params :issue_params do
          optional :description, type: String, desc: 'The description of an issue'
          optional :assignee_id, type: Integer, desc: 'The ID of a user to assign issue'
          optional :milestone_id, type: Integer, desc: 'The ID of a milestone to assign issue'
          optional :labels, type: String, desc: 'Comma-separated list of label names'
          optional :due_date, type: String, desc: 'Date time string in the format YEAR-MONTH-DAY'
          optional :confidential, type: Boolean, desc: 'Boolean parameter if the issue should be confidential'
        end
      end

      resource :issues do
        desc "Get currently authenticated user's issues" do
          success ::API::Entities::Issue
        end
        params do
          optional :state, type: String, values: %w[opened closed all], default: 'all',
                           desc: 'Return opened, closed, or all issues'
          use :issues_params
        end
        get do
          issues = find_issues(scope: 'authored')

          present paginate(issues), with: ::API::Entities::Issue, current_user: current_user
        end
      end

      params do
        requires :id, type: String, desc: 'The ID of a group'
      end
      resource :groups do
        desc 'Get a list of group issues' do
          success ::API::Entities::Issue
        end
        params do
          optional :state, type: String, values: %w[opened closed all], default: 'opened',
                           desc: 'Return opened, closed, or all issues'
          use :issues_params
        end
        get ":id/issues" do
          group = find_group!(params[:id])

          issues = find_issues(group_id: group.id, state: params[:state] || 'opened', match_all_labels: true)

          present paginate(issues), with: ::API::Entities::Issue, current_user: current_user
        end
      end

      params do
        requires :id, type: String, desc: 'The ID of a project'
      end
      resource :projects do
        include TimeTrackingEndpoints

        desc 'Get a list of project issues' do
          detail 'iid filter is deprecated have been removed on V4'
          success ::API::Entities::Issue
        end
        params do
          optional :state, type: String, values: %w[opened closed all], default: 'all',
                           desc: 'Return opened, closed, or all issues'
          optional :iid, type: Integer, desc: 'Return the issue having the given `iid`'
          use :issues_params
        end
        get ":id/issues" do
          project = find_project(params[:id])

          issues = find_issues(project_id: project.id)

          present paginate(issues), with: ::API::Entities::Issue, current_user: current_user, project: user_project
        end

        desc 'Get a single project issue' do
          success ::API::Entities::Issue
        end
        params do
          requires :issue_id, type: Integer, desc: 'The ID of a project issue'
        end
        get ":id/issues/:issue_id" do
          issue = find_project_issue(params[:issue_id])
          present issue, with: ::API::Entities::Issue, current_user: current_user, project: user_project
        end

        desc 'Create a new project issue' do
          success ::API::Entities::Issue
        end
        params do
          requires :title, type: String, desc: 'The title of an issue'
          optional :created_at, type: DateTime,
                                desc: 'Date time when the issue was created. Available only for admins and project owners.'
          optional :merge_request_for_resolving_discussions, type: Integer,
                                                             desc: 'The IID of a merge request for which to resolve discussions'
          use :issue_params
        end
        post ':id/issues' do
          # Setting created_at time only allowed for admins and project owners
          unless current_user.admin? || user_project.owner == current_user
            params.delete(:created_at)
          end

          issue_params = declared_params(include_missing: false)

          if merge_request_iid = params[:merge_request_for_resolving_discussions]
            issue_params[:merge_request_for_resolving_discussions] = MergeRequestsFinder.new(current_user, project_id: user_project.id).
              execute.
              find_by(iid: merge_request_iid)
          end

          issue = ::Issues::CreateService.new(user_project,
                                              current_user,
                                              issue_params.merge(request: request, api: true)).execute
          render_spam_error! if issue.spam?

          if issue.valid?
            present issue, with: ::API::Entities::Issue, current_user: current_user, project: user_project
          else
            render_validation_error!(issue)
          end
        end

        desc 'Update an existing issue' do
          success ::API::Entities::Issue
        end
        params do
          requires :issue_id, type: Integer, desc: 'The ID of a project issue'
          optional :title, type: String, desc: 'The title of an issue'
          optional :updated_at, type: DateTime,
                                desc: 'Date time when the issue was updated. Available only for admins and project owners.'
          optional :state_event, type: String, values: %w[reopen close], desc: 'State of the issue'
          use :issue_params
          at_least_one_of :title, :description, :assignee_id, :milestone_id,
                          :labels, :created_at, :due_date, :confidential, :state_event
        end
        put ':id/issues/:issue_id' do
          issue = user_project.issues.find(params.delete(:issue_id))
          authorize! :update_issue, issue

          # Setting created_at time only allowed for admins and project owners
          unless current_user.admin? || user_project.owner == current_user
            params.delete(:updated_at)
          end

          update_params = declared_params(include_missing: false).merge(request: request, api: true)

          issue = ::Issues::UpdateService.new(user_project,
                                              current_user,
                                              update_params).execute(issue)

          render_spam_error! if issue.spam?

          if issue.valid?
            present issue, with: ::API::Entities::Issue, current_user: current_user, project: user_project
          else
            render_validation_error!(issue)
          end
        end

        desc 'Move an existing issue' do
          success ::API::Entities::Issue
        end
        params do
          requires :issue_id, type: Integer, desc: 'The ID of a project issue'
          requires :to_project_id, type: Integer, desc: 'The ID of the new project'
        end
        post ':id/issues/:issue_id/move' do
          issue = user_project.issues.find_by(id: params[:issue_id])
          not_found!('Issue') unless issue

          new_project = Project.find_by(id: params[:to_project_id])
          not_found!('Project') unless new_project

          begin
            issue = ::Issues::MoveService.new(user_project, current_user).execute(issue, new_project)
            present issue, with: ::API::Entities::Issue, current_user: current_user, project: user_project
          rescue ::Issues::MoveService::MoveError => error
            render_api_error!(error.message, 400)
          end
        end

        desc 'Delete a project issue'
        params do
          requires :issue_id, type: Integer, desc: 'The ID of a project issue'
        end
        delete ":id/issues/:issue_id" do
          issue = user_project.issues.find_by(id: params[:issue_id])
          not_found!('Issue') unless issue

          authorize!(:destroy_issue, issue)
          issue.destroy
        end
      end
    end
  end
end
