upgrade-llvm.yml

name: Upgrade halide-llvm

on:
  schedule:
    - cron: "0 6 * * *"  # Daily at 1am EST / 2am EDT
  workflow_dispatch:

env:
  BRANCH: automated/upgrade-halide-llvm

jobs:
  upgrade:
    runs-on: ubuntu-slim
    steps:
      - uses: actions/create-github-app-token@v3
        id: app-token
        with:
          app-id: ${{ secrets.LLVM_UPDATER_ID }}
          private-key: ${{ secrets.LLVM_UPDATER_PRIVATE_KEY }}

      - name: Get GitHub App user ID
        id: get-user-id
        run: echo "user-id=$(gh api "/users/${{ steps.app-token.outputs.app-slug }}[bot]" --jq .id)" >> "$GITHUB_OUTPUT"
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}

      - name: Configure git and environment
        run: |
          echo "GH_TOKEN=${{ steps.app-token.outputs.token }}" >> "$GITHUB_ENV"
          git config --global user.name "${{ steps.app-token.outputs.app-slug }}[bot]"
          git config --global user.email "${{ steps.get-user-id.outputs.user-id }}+${{ steps.app-token.outputs.app-slug }}[bot]@users.noreply.github.com"

      - uses: actions/checkout@v6
        with:
          ref: main
          token: ${{ steps.app-token.outputs.token }}

      - name: Switch to existing PR branch if present
        id: branch
        run: |
          if gh pr view "$BRANCH" --json state -q .state 2>/dev/null | grep -q OPEN; then
            echo "pr-exists=true" >> "$GITHUB_OUTPUT"
            git fetch origin "$BRANCH"
            git checkout "$BRANCH"
          else
            echo "pr-exists=false" >> "$GITHUB_OUTPUT"
            # Delete stale remote branch (e.g. leftover from a merged PR)
            git push origin --delete "$BRANCH" 2>/dev/null || true
            git checkout -b "$BRANCH"
          fi

      - uses: astral-sh/setup-uv@v7

      - name: Upgrade halide-llvm
        run: uv lock -P halide-llvm

      - name: Check for changes
        id: diff
        run: |
          if git diff --quiet uv.lock; then
            echo "changed=false" >> "$GITHUB_OUTPUT"
          else
            echo "changed=true" >> "$GITHUB_OUTPUT"

            # Extract new resolved versions from the diff
            VERSIONS=$(git diff uv.lock \
              | grep '^+.*name = "halide-llvm", version' \
              | sed 's/.*version = "\([^"]*\)".*/\1/' \
              | tr '\n' ',' | sed 's/,/, /g; s/, $//')
            echo "versions=$VERSIONS" >> "$GITHUB_OUTPUT"
          fi

      - name: Create or update PR
        if: steps.diff.outputs.changed == 'true'
        run: |
          TITLE="Upgrade halide-llvm to ${{ steps.diff.outputs.versions }}"

          git add uv.lock
          git commit -m "$TITLE"

          if [ "${{ steps.branch.outputs.pr-exists }}" = "true" ]; then
            git push -u origin "$BRANCH"
            gh pr edit "$BRANCH" --title "$TITLE"
          else
            git push -u origin "$BRANCH"
            gh pr create \
              --title "$TITLE" \
              --body "Automated upgrade via \`uv lock -P halide-llvm\`." \
              --head "$BRANCH"
          fi