name: CI - Perf

# EXPERIMENTAL: This workflow is running with --tolerate-failure flag for phpbench
# This is to gather data for a future historical interleaving of performance benchmarks.

on:
  # Run once per day no matter what
  schedule:
    - cron: '0 0 * * *'
  # Run on push to main, so we get a data point every merge
  push:
    branches:
      - main
  # Allow manual triggering with rebaseline option
  workflow_dispatch:
    inputs:
      baseline:
        description: 'Baseline mode. latest: compare against latest benchmarks; rebaseline: store new baseline.'
        type: choice
        default: 'latest'
        options:
          - 'latest'
          - 'rebaseline'
      pull:
        description: 'Pull request number to benchmark (optional)'
        required: false

jobs:
  pr-benchmarks:
    name: PR Benchmarks
    if: ${{ github.event_name == 'workflow_dispatch' && github.event.inputs.pull }}
    runs-on: ubuntu-latest
    env:
      BENCHMARK_SHA: ${{ github.sha }}

    permissions:
      contents: read

    steps:
      - uses: actions/checkout@v6
        with:
          persist-credentials: false

      - name: Checkout PR head
        run: |
          set -euo pipefail
          PR=${{ github.event.inputs.pull }}
          # Validate that PR is numeric to avoid injection or unexpected ref resolution
          if ! printf '%s\n' "$PR" | grep -Eq '^[0-9]+$'; then
            echo "Invalid pull request number: '$PR'. Expected a numeric value." >&2
            exit 1
          fi
          # fetch the pull request head (works for forks)
          git fetch origin "pull/${PR}/head:pr-${PR}" || git fetch origin "+refs/pull/${PR}/head:pr-${PR}"
          git checkout "pr-${PR}"
          echo "Checked out PR #${PR}"
          echo "BENCHMARK_SHA=$(git rev-parse --verify HEAD)" >> "$GITHUB_ENV"

      - uses: ./.github/actions/setup-action
        with:
          extensions: xdebug

      - name: Fetch Benchmarks
        run: |
          git fetch origin benchmarks
          mkdir -p .phpbench
          git checkout origin/benchmarks -- .phpbench || echo "No previous benchmarks found"
      
      - name: Run Benchmarks
        run: |
          # Baseline does not exist or rebaseline requested. Generate it.
          if [ -z "$(ls -A .phpbench)" ] || [ "${{ github.event.inputs.baseline || 'latest' }}" = "rebaseline" ]; then
            vendor/bin/phpbench run --report=aggregate --progress=plain --store --tag=${BENCHMARK_SHA}

          # Baseline exists. Compare against it.
          else
            vendor/bin/phpbench run --report=aggregate --progress=plain --store --tag=${BENCHMARK_SHA} --ref=latest --tolerate-failure
          fi
          
          # Generate report for human consumption
          vendor/bin/phpbench report --report=aggregate --ref=latest |
            tail -n+2 | head -n-2 | tr '+' '|' > report.md

          cat report.md > "$GITHUB_STEP_SUMMARY"

  historical-benchmarks:
    name: Historical Benchmarks
    if: >-
      github.event_name != 'workflow_dispatch' ||
      !github.event.inputs.pull
    runs-on: ubuntu-latest
    env:
      BENCHMARK_SHA: ${{ github.sha }}

    permissions:
      contents: write

    steps:
      - uses: actions/checkout@v6
        with:
          persist-credentials: true

      - uses: ./.github/actions/setup-action
        with:
          extensions: xdebug

      - name: Fetch Benchmarks
        run: |
          git fetch origin benchmarks
          mkdir -p .phpbench
          git checkout origin/benchmarks -- .phpbench || echo "No previous benchmarks found"

      - name: Run Benchmarks
        run: |
          # Baseline does not exist or rebaseline requested. Generate it.
          if [ -z "$(ls -A .phpbench)" ] || [ "${{ github.event.inputs.baseline || 'latest' }}" = "rebaseline" ]; then
            vendor/bin/phpbench run --report=aggregate --progress=plain --store --tag=${BENCHMARK_SHA}

          # Baseline exists. Compare against it.
          else
            vendor/bin/phpbench run --report=aggregate --progress=plain --store --tag=${BENCHMARK_SHA} --ref=latest --tolerate-failure
          fi

          # Generate report for human consumption
          vendor/bin/phpbench report --report=aggregate --ref=latest |
            tail -n+2 | head -n-2 | tr '+' '|' > report.md

          cat report.md

      - name: Commit Results
        # only on: main push, schedule, workflow_dispatch+rebaseline
        if: >-
          (github.ref == 'refs/heads/main' && github.event_name == 'push') ||
          (github.event_name == 'schedule') ||
          (github.event_name == 'workflow_dispatch' && github.event.inputs.baseline == 'rebaseline')
        run: |
          set -euo pipefail
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git checkout benchmarks
          mv -f report.md latest.md
          git add .phpbench latest.md
          git commit -m "Store benchmark results [skip ci]" || echo "No changes to commit"
          git push origin benchmarks

      - name: Restore workspace
        if: always()
        run: |
          set -euo pipefail
          echo "Restoring workspace to original commit: ${GITHUB_SHA}"
          git fetch origin || true
          git checkout --detach "${GITHUB_SHA}"
          git reset --hard "${GITHUB_SHA}"