name: Pacquet Micro-Benchmark

on:
  workflow_dispatch:
  pull_request:
    types: [opened, synchronize]
    paths:
      - 'pacquet/**/*.rs'
      - 'pacquet/**/Cargo.toml'
      - 'Cargo.toml'
      - 'Cargo.lock'
      - 'rust-toolchain.toml'
      - 'pacquet/tasks/micro-benchmark/fixtures/**'
      - '.github/actions/rustup/**'
      - '.github/actions/binstall/**'
      - '.github/workflows/pacquet-micro-benchmark.yml'

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
  cancel-in-progress: true

permissions:
  contents: read

jobs:
  benchmark:
    strategy:
      matrix:
        os: [ubuntu-latest] # `macos-latest` is too unstable to be useful for benchmark, the variance is always huge.
    name: Run benchmark on ${{ matrix.os }}
    runs-on: ${{ matrix.os }}
    steps:
      - name: Checkout Main Branch
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          ref: main # Checkout main first because the cache is warm
          persist-credentials: false

      - name: Install Rust Toolchain
        uses: ./.github/actions/rustup
        with:
          shared-key: micro-benchmark

      - name: Compile
        run: cargo build --release --bin=micro-benchmark

      - name: Sleep for CPU cooldown
        shell: bash
        run: sleep 15s

      - name: Run Bench on Main Branch
        run: cargo run --bin=micro-benchmark --release -- --save-baseline main

      - name: Checkout PR Branch
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          clean: false
          ref: ${{ github.event.pull_request.head.sha }}
          persist-credentials: false

      - name: Compile
        run: cargo build --release --bin=micro-benchmark

      - name: Sleep for CPU cooldown
        shell: bash
        run: sleep 15s

      - name: Run Bench on PR Branch
        run: cargo run --bin=micro-benchmark --release -- --save-baseline pr

      - name: Upload benchmark results
        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
        with:
          name: benchmark-results-${{ matrix.os }}
          path: ./target/criterion

  benchmark-compare:
    runs-on: ubuntu-latest
    name: Compare Benchmarks
    needs:
      - benchmark
    permissions:
      contents: read
      issues: write
      pull-requests: write

    steps:
      - name: Install critcmp
        uses: taiki-e/install-action@e1c4cd42111751368541a7cb5db3522bd1f846a4 # v2.78.0
        with:
          tool: critcmp

      - name: Linux | Download PR benchmark results
        uses: actions/download-artifact@70fc10c6e5e1ce46ad2ea6f2b72d43f7d47b13c3 # v8.0.0
        with:
          name: benchmark-results-ubuntu-latest
          path: ./target/criterion

      - name: Linux | Compare benchmark results
        shell: bash
        run: |
          echo "## Micro-Benchmark Results" >> summary.md
          echo "### Linux" >> summary.md
          echo "\`\`\`" >> summary.md
          critcmp main pr >> summary.md
          echo "\`\`\`" >> summary.md
          echo "" >> summary.md

      - name: Linux | Cleanup benchmark results
        run: rm -rf ./target/criterion

      - name: Find Comment
        # Check if the event is not triggered by a fork
        if: github.event.pull_request.head.repo.full_name == github.repository
        uses: peter-evans/find-comment@b30e6a3c0ed37e7c023ccd3f1db5c6c0b0c23aad # v4.0.0
        id: fc
        with:
          issue-number: ${{ github.event.pull_request.number }}
          comment-author: 'github-actions[bot]'
          body-includes: Micro-Benchmark Results

      - name: Create or update comment
        # Check if the event is not triggered by a fork
        if: github.event.pull_request.head.repo.full_name == github.repository
        uses: peter-evans/create-or-update-comment@e8674b075228eee787fea43ef493e45ece1004c9 # v5.0.0
        with:
          issue-number: ${{ github.event.pull_request.number }}
          edit-mode: replace
          comment-id: ${{ steps.fc.outputs.comment-id }}
          body-file: summary.md