on:
  push:
    branches:
      - master
      - main
    paths:
      - "**.go"
  pull_request:
    paths:
      - "**.go"

permissions:
  # deployments permission to deploy GitHub pages website
  deployments: write
  # contents permission to update benchmark contents in gh-pages branch
  contents: write
  # allow posting comments to pull request
  pull-requests: write

name: Benchmark
jobs:
  Compare:
    runs-on: ubuntu-latest
    steps:
      - name: Fetch Repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0 # to be able to retrieve the last commit in main

      - name: Install Go
        uses: actions/setup-go@v5
        with:
          # NOTE: Keep this in sync with the version from go.mod
          go-version: "1.23.x"

      - name: Run Benchmark
        run: set -o pipefail; go test ./... -benchmem -run=^$ -bench . | tee output.txt
      ### hack because of the problem with duplicated benchmark names - https://github.com/benchmark-action/github-action-benchmark/issues/264
      - name: Extract Module Name
        id: extract-module
        run: |
          MODULE_NAME=$(awk '/^module / {print $2}' go.mod)
          echo "MODULE_NAME=$MODULE_NAME" >> $GITHUB_ENV

      - name: Identify Duplicate Benchmark Names
        run: |
          awk '/^Benchmark/ {print $1}' output.txt | sort | uniq -d > duplicate_benchmarks.txt

      - name: Add Normalized Package Prefix to Duplicate Benchmark Names
        run: |
          awk -v MODULE_NAME="$MODULE_NAME" '
            FNR==NR {duplicates[$1]; next}
            /^pkg: / { package=$2 }
            /^Benchmark/ {
              if ($1 in duplicates) {
                sub("^" MODULE_NAME "/?", "", package)
                gsub("/", "_", package)
                print $1 "_" package substr($0, length($1) + 1)
              } else {
                print $0
              }
              next
            }
            { print }
          ' duplicate_benchmarks.txt output.txt > output_prefixed.txt
          mv output_prefixed.txt output.txt
      ### end

      # NOTE: Benchmarks could change with different CPU types
      - name: Get GitHub Runner System Information
        uses: kenchan0130/actions-system-info@v1.3.0
        id: system-info

      - name: Get Main branch SHA
        id: get-main-branch-sha
        run: |
          SHA=$(git rev-parse origin/main)
          echo "sha=$SHA" >> $GITHUB_OUTPUT

      - name: Get Benchmark Results from main branch
        id: cache
        uses: actions/cache/restore@v4
        with:
          path: ./cache
          key: ${{ steps.get-main-branch-sha.outputs.sha }}-${{ runner.os }}-${{ steps.system-info.outputs.cpu-model }}-benchmark

      # This will only run if we have Benchmark Results from main branch
      - name: Compare PR Benchmark Results with main branch
        uses: benchmark-action/github-action-benchmark@v1.20.4
        if: steps.cache.outputs.cache-hit == 'true'
        with:
          tool: 'go'
          output-file-path: output.txt
          external-data-json-path: ./cache/benchmark-data.json
          # Do not save the data (This allows comparing benchmarks)
          save-data-file: false
          fail-on-alert: true
          # Comment on the PR if the branch is not a fork
          comment-on-alert: ${{ github.event.pull_request.head.repo.fork == false }}
          github-token: ${{ secrets.GITHUB_TOKEN }}
          summary-always: true
          alert-threshold: "150%"

      - name: Store Benchmark Results for main branch
        uses: benchmark-action/github-action-benchmark@v1.20.4
        if: ${{ github.ref_name == 'main' }}
        with:
          tool: 'go'
          output-file-path: output.txt
          external-data-json-path: ./cache/benchmark-data.json
          # Save the data to external file (cache)
          save-data-file: true
          fail-on-alert: false
          github-token: ${{ secrets.GITHUB_TOKEN }}
          summary-always: true
          alert-threshold: "150%"

      - name: Publish Benchmark Results to GitHub Pages
        uses: benchmark-action/github-action-benchmark@v1.20.4
        if: ${{ github.ref_name == 'main' }}
        with:
          tool: 'go'
          output-file-path: output.txt
          benchmark-data-dir-path: "benchmarks"
          fail-on-alert: false
          github-token: ${{ secrets.GITHUB_TOKEN }}
          comment-on-alert: true
          summary-always: true
          # Save the data to external file (GitHub Pages)
          save-data-file: true
          alert-threshold: "150%"
          # TODO: reactivate it later -> when v3 is the stable one
          #auto-push: ${{ github.event_name == 'push' || github.event_name == 'workflow_dispatch' }}
          auto-push: false

      - name: Update Benchmark Results cache
        uses: actions/cache/save@v4
        if: ${{ github.ref_name == 'main' }}
        with:
          path: ./cache
          key: ${{ steps.get-main-branch-sha.outputs.sha }}-${{ runner.os }}-${{ steps.system-info.outputs.cpu-model }}-benchmark