name: Check Line Counts
on:
  pull_request_target:

# Cancel the workflow in progress in newer build is about to start.
concurrency:
  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
  cancel-in-progress: true

jobs:
  checkbranch:
    name: Check PR Branch status
    runs-on: ubuntu-latest
    outputs:
      branchstat: ${{ steps.brstat.outputs.stat}}
    steps:
      - name: Check code from PR branch
        uses: actions/checkout@v6
        with:
          repository: ${{ github.event.pull_request.head.repo.full_name }}
          ref: ${{ github.event.pull_request.head.sha }}
          fetch-depth: 0
          # PR code is only inspected with git rev-list, never executed
          allow-unsafe-pr-checkout: true
          persist-credentials: false
      - name: Check whether branch is up-to-date
        id: brstat
        run: |
          # fetch master from the base repo (tinygrad/tinygrad on GitHub, the mirror on Gitea), not the PR head remote
          git fetch "${{ github.event.pull_request.base.repo.clone_url }}" master
          echo "${{ github.event.pull_request.head.sha }}"
          git rev-list --left-right --count FETCH_HEAD...${{ github.event.pull_request.head.sha }} | awk '{print "Behind "$1" - Ahead "$2""}'
          count=$(git rev-list --left-right --count FETCH_HEAD...${{ github.event.pull_request.head.sha }} | awk '{print $1}')
          if [ $count -gt 0 ]
          then
            echo "Current branch is behind ${{ github.event.pull_request.base.repo.full_name }} master branch!"
            echo "stat=true" >> "$GITHUB_OUTPUT"
          else
            echo "stat=false" >> "$GITHUB_OUTPUT"
          fi

  szdiff:
    name: Core Library Line Difference
    permissions:
      contents: read
      pull-requests: write
    runs-on: ubuntu-latest
    needs: checkbranch
    if: needs.checkbranch.outputs.branchstat == 'false'
    steps:
      - name: Checkout code from PR branch
        uses: actions/checkout@v6
        with:
          repository: ${{ github.event.pull_request.head.repo.full_name }}
          ref: ${{ github.event.pull_request.head.sha }}
          path: pr
          # PR code is only line-counted by master's sz.py, never executed
          allow-unsafe-pr-checkout: true
          persist-credentials: false
        # the base default to tinygrad master and cannot be other fork branch for security purpose
      - name: Checkout code from tinygrad master
        uses: actions/checkout@v6
        with:
          path: base
      - name: Set up Python 3.12
        uses: actions/setup-python@v6
        with:
          python-version: '3.12'
      - name: Count Line Diff
        run: |
          BASE="$GITHUB_WORKSPACE/base"
          PR="$GITHUB_WORKSPACE/pr"
          pip install tabulate $BASE
          cp "$BASE/sz.py" .
          python sz.py "$BASE" "$PR" > loc_content.txt
      - name: Comment Code Line Diff
        continue-on-error: false
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
          MARKER: "### Changes"
          BODY_FILE: loc_content.txt
        # note: run the script from the base checkout, never from the PR checkout
        run: python3 "$GITHUB_WORKSPACE/base/.github/workflows/sticky_comment.py"

  rebase:
    name: Core Library Line Difference
    permissions:
      pull-requests: write
    runs-on: ubuntu-latest
    needs: checkbranch
    if: needs.checkbranch.outputs.branchstat == 'true'
    steps:
      # pull_request_target: a plain checkout gets the base repo, so no PR code is executed
      - uses: actions/checkout@v6
      - name: Comment Rebase
        continue-on-error: false
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
          MARKER: "line count difference bot is disabled"
          MESSAGE: |
            This branch currently is behind ${{ github.event.pull_request.base.repo.full_name }} master. The line count difference bot is disabled.
        run: python3 .github/workflows/sticky_comment.py