/**
 * @license Copyright 2021 The Lighthouse Authors. All Rights Reserved.
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
 */

import {FunctionComponent} from 'preact';

import {ReportUtils} from '../../../report/renderer/report-utils.js';
import {Separator} from '../common';
import {CategoryScore} from '../wrappers/category-score';
import {useI18n, useStringFormatter, useLocalizedStrings} from '../i18n/i18n';
import {Markdown} from '../wrappers/markdown';

import type {UIStringsType} from '../i18n/ui-strings';

const MAX_TOOLTIP_AUDITS = 2;

type ScoredAuditRef = LH.ReportResult.AuditRef & {result: {score: number}};

function getGatherModeLabel(gatherMode: LH.Result.GatherMode, strings: UIStringsType) {
  switch (gatherMode) {
    case 'navigation': return strings.navigationReport;
    case 'timespan': return strings.timespanReport;
    case 'snapshot': return strings.snapshotReport;
  }
}

function getCategoryRating(rating: string, strings: UIStringsType) {
  switch (rating) {
    case 'pass': return strings.ratingPass;
    case 'average': return strings.ratingAverage;
    case 'fail': return strings.ratingFail;
    case 'error': return strings.ratingError;
  }
}

function getScoreToBeGained(audit: ScoredAuditRef): number {
  return audit.weight * (1 - audit.result.score);
}

function getOverallSavings(audit: LH.ReportResult.AuditRef): number {
  return (
    audit.result.details &&
    audit.result.details.overallSavingsMs
  ) || 0;
}

const SummaryTooltipAudit: FunctionComponent<{audit: LH.ReportResult.AuditRef}> = ({audit}) => {
  const rating = ReportUtils.calculateRating(audit.result.score, audit.result.scoreDisplayMode);
  return (
    <div className={`SummaryTooltipAudit SummaryTooltipAudit--${rating}`}>
      <Markdown text={audit.result.title}/>
    </div>
  );
};

const SummaryTooltipAudits: FunctionComponent<{category: LH.ReportResult.Category}> =
({category}) => {
  const strings = useLocalizedStrings();

  function isRelevantAudit(audit: LH.ReportResult.AuditRef): audit is ScoredAuditRef {
    return audit.result.score !== null &&
      // Metrics should not be displayed in this group.
      audit.group !== 'metrics' &&
      // Audits in performance group "hidden" should not be counted.
      (audit.group !== 'hidden' || category.id !== 'performance') &&
      // We don't want unweighted audits except for opportunities with potential savings.
      (audit.weight > 0 || getOverallSavings(audit) > 0) &&
      // Passing audits should never be high impact.
      !ReportUtils.showAsPassed(audit.result);
  }

  const audits = category.auditRefs
    .filter(isRelevantAudit)
    .sort((a, b) => {
      // Remaining score should always be 0 for perf opportunities because weight is 0.
      // In that case, we want to sort by `overallSavingsMs`.
      const remainingScoreA = getScoreToBeGained(a);
      const remainingScoreB = getScoreToBeGained(b);
      if (remainingScoreA !== remainingScoreB) return remainingScoreB - remainingScoreA;
      return getOverallSavings(b) - getOverallSavings(a);
    })
    .splice(0, MAX_TOOLTIP_AUDITS);
  if (!audits.length) return null;

  return (
    <div className="SummaryTooltipAudits">
      <div className="SummaryTooltipAudits__title">{strings.highestImpact}</div>
      {
        audits.map(audit => <SummaryTooltipAudit key={audit.id} audit={audit}/>)
      }
    </div>
  );
};

const SummaryTooltip: FunctionComponent<{
  category: LH.ReportResult.Category,
  gatherMode: LH.Result.GatherMode,
  url: string,
}> = ({category, gatherMode, url}) => {
  const strings = useLocalizedStrings();
  const str_ = useStringFormatter();
  const {
    numPassed,
    numPassableAudits,
    numInformative,
    totalWeight,
  } = ReportUtils.calculateCategoryFraction(category);

  const i18n = useI18n();
  const displayAsFraction = ReportUtils.shouldDisplayAsFraction(gatherMode);
  const score = displayAsFraction ?
    numPassed / numPassableAudits :
    category.score;
  const rating = score === null ? 'error' : ReportUtils.calculateRating(score);

  return (
    <div className="SummaryTooltip">
      <div className="SummaryTooltip__title">{getGatherModeLabel(gatherMode, strings)}</div>
      <div className="SummaryTooltip__url">{url}</div>
      <Separator/>
      <div className="SummaryTooltip__category">
        <div className="SummaryTooltip__category-title">
          {category.title}
        </div>
        {
          totalWeight !== 0 &&
            <div className={`SummaryTooltip__rating SummaryTooltip__rating--${rating}`}>
              <span>{getCategoryRating(rating, strings)}</span>
              {
                !displayAsFraction && category.score !== null && <>
                  <span> · </span>
                  <span>{i18n.formatter.formatInteger(category.score * 100)}</span>
                </>
              }
            </div>
        }
      </div>
      <div className="SummaryTooltip__fraction">
        <span>{str_(strings.passedAuditCount, {numPassed})}</span>
        <span> / </span>
        <span>{str_(strings.passableAuditCount, {numPassableAudits})}</span>
      </div>
      {numInformative !== 0 &&
        <div className="SummaryTooltip__informative">
          {str_(strings.informativeAuditCount, {numInformative})}
        </div>
      }
      <SummaryTooltipAudits category={category}/>
    </div>
  );
};

const SummaryCategory: FunctionComponent<{
  category: LH.ReportResult.Category|undefined,
  href: string,
  gatherMode: LH.Result.GatherMode,
  finalDisplayedUrl: string,
}> = ({category, href, gatherMode, finalDisplayedUrl}) => {
  return (
    <div className="SummaryCategory">
      {
        category ?
          <div className="SummaryCategory__content">
            <CategoryScore
              category={category}
              href={href}
              gatherMode={gatherMode}
            />
            <SummaryTooltip category={category} gatherMode={gatherMode} url={finalDisplayedUrl}/>
          </div> :
          <div className="SummaryCategory__null" data-testid="SummaryCategory__null"/>
      }
    </div>
  );
};

export {
  SummaryTooltip,
  SummaryCategory,
};