# frozen_string_literal: true

module GitlabQuality
  module TestTooling
    module Report
      # Uses the API to create GitLab issues for slow tests
      #
      # - Takes the JSON test reports like rspec-*.json`
      # - Takes a project where slow issues should be created
      # - Find issue by title (with test description or test file)
      # - Add test metadata, duration to the issue with group and category labels
      class SlowTestIssue < ReportAsIssue
        include Concerns::GroupAndCategoryLabels
        include Concerns::IssueReports

        IDENTITY_LABELS       = ['test', 'rspec:slow test', 'rspec profiling', 'automation:bot-authored'].freeze
        NEW_ISSUE_LABELS      = Set.new(['test', 'type::maintenance', 'maintenance::performance', 'priority::3', 'severity::3']).freeze
        SEARCH_LABELS         = ['test'].freeze
        FOUND_IN_MR_LABEL     = '~"found:in MR"'
        FOUND_IN_MASTER_LABEL = '~"found:master"'
        REPORT_SECTION_HEADER = '### Slowness reports'
        REPORTS_DOCUMENTATION = <<~DOC
          Slow tests were detected, please see the [test speed best practices guide](https://docs.gitlab.com/ee/development/testing_guide/best_practices.html#test-speed)
          to improve them. More context available about this issue in the [top slow tests guide](https://docs.gitlab.com/ee/development/testing_guide/best_practices.html#top-slow-tests).

          Add `allowed_to_be_slow: true` to the RSpec test if this is a legit slow test and close the issue.
        DOC

        private

        def run!
          puts "Reporting slow tests in `#{files.join(',')}` as issues in project `#{project}` via the API at `#{Runtime::Env.gitlab_api_base}`."

          TestResults::Builder.new(files).test_results_per_file do |test_results|
            puts "=> Reporting #{test_results.count} tests in #{test_results.path}"

            process_test_results(test_results)
          end
        end

        def process_test_results(test_results)
          test_results.each do |test|
            next unless test.slow_test?

            puts " => Reporting slowness for test '#{test.name}'..."

            issues = find_issues_by_hash(test_hash(test), state: 'opened', labels: SEARCH_LABELS)
            issues << create_issue(test) if issues.empty?

            update_reports(issues, test)
            collect_issues(test, issues)
          end
        end

        def test_is_applicable?(test)
          test.slow_test?
        end

        def update_reports(issues, test)
          issues.each do |issue|
            puts "   => Adding the slow test to the existing issue: #{issue.web_url}"
            add_report_to_issue(issue: issue, test: test, related_issues: (issues - [issue]))
          end
        end

        def add_report_to_issue(issue:, test:, related_issues:)
          current_reports_note = existing_reports_note(issue: issue)
          new_reports_list = add_report_for_test(current_reports_content: current_reports_note&.body.to_s, test: test)

          note_body = [
            new_reports_list.to_s,
            slowness_status_labels_quick_action(new_reports_list.reports_count),
            identity_labels_quick_action,
            relate_issues_quick_actions(related_issues)
          ].join("\n")

          if current_reports_note
            gitlab.edit_issue_note(
              issue_iid: issue.iid,
              note_id: current_reports_note.id,
              note: note_body
            )
          else
            gitlab.create_issue_note(iid: issue.iid, note: note_body)
          end
        end

        def existing_reports_note(issue:)
          gitlab.find_issue_notes(iid: issue.iid).find do |note|
            note.body.start_with?(REPORT_SECTION_HEADER)
          end
        end

        def add_report_for_test(current_reports_content:, test:)
          increment_reports(
            current_reports_content: current_reports_content,
            test: test,
            reports_section_header: REPORT_SECTION_HEADER,
            item_extra_content: "(#{test.run_time} seconds) #{found_label}",
            reports_extra_content: REPORTS_DOCUMENTATION
          )
        end

        def found_label
          if ENV.key?('CI_MERGE_REQUEST_IID')
            FOUND_IN_MR_LABEL
          else
            FOUND_IN_MASTER_LABEL
          end
        end

        # The report count is based on the percentiles of slowness issues.
        #
        # See https://gitlab.com/gitlab-org/quality/engineering-productivity/team/-/blob/main/scripts/unhealthy_test_issues_statistics.rb
        # to gather these statistics.
        #
        # P75       => slowness::4
        # P90       => slowness::3
        # P95       => slowness::2
        # Above P95 => slowness::1
        def slowness_status_labels_quick_action(reports_count)
          case reports_count
          when 40..Float::INFINITY
            '/label ~"slowness::1"'
          when 28..39
            '/label ~"slowness::2"'
          when 12..27
            '/label ~"slowness::3"'
          else
            '/label ~"slowness::4"'
          end
        end

        def identity_labels_quick_action
          labels_list = IDENTITY_LABELS.map { |label| %(~"#{label}") }.join(' ')
          %(/label #{labels_list})
        end

        def relate_issues_quick_actions(issues)
          issues.map do |issue|
            "/relate #{issue.web_url}"
          end.join("\n")
        end
      end
    end
  end
end