name: rustc-pull

on:
  workflow_dispatch:
  schedule:
    # Run at 04:00 UTC every Monday
    - cron: '0 4 * * 1'

jobs:
  pull:
    if: github.repository == 'rust-lang/rustc-dev-guide'
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
    steps:
      - uses: actions/checkout@v4
        with:
          # We need the full history for josh to work
          fetch-depth: '0'
      - name: Install stable Rust toolchain
        run: rustup update stable
      - uses: Swatinem/rust-cache@v2
        with:
          workspaces: "josh-sync"
          # Cache the josh directory with checked out rustc
          cache-directories: "/home/runner/.cache/rustc-dev-guide-josh"
      - name: Install josh
        run: RUSTFLAGS="--cap-lints warn" cargo +stable install josh-proxy --git https://github.com/josh-project/josh --tag r24.10.04
      - name: Setup bot git name and email
        run: |
          git config --global user.name 'The rustc-dev-guide Cronjob Bot'
          git config --global user.email 'github-actions@github.com'
      - name: Perform rustc-pull
        run: cargo run --manifest-path josh-sync/Cargo.toml -- rustc-pull
      - name: Push changes to a branch
        run: |
          # Update a sticky branch that is used only for rustc pulls
          BRANCH="rustc-pull"
          git switch -c $BRANCH
          git push -u origin $BRANCH --force
      - name: Create pull request
        run: |
          # Check if an open pull request for an rustc pull update already exists
          # If it does, the previous push has just updated it
          # If not, we create it now
          RESULT=`gh pr list --author github-actions[bot] --state open -q 'map(select(.title=="Rustc pull update")) | length' --json title`
          if [[ "$RESULT" -eq 0 ]]; then
            echo "Creating new pull request"
            gh pr create -B master --title 'Rustc pull update' --body 'Latest update from rustc.'
          else
            echo "Updated existing pull request"
          fi
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}