name: Sync Rebuild Triggers

# Rebuilds ride the unattended lane, like track-branches.yml: the pkgrel bump
# PR builds on the droplets, auto-merge lands it once `result`, `self-tests`
# and `build-isolation` are green, and the merge publishes. A rebuild that
# fails stays an unmerged red PR for a maintainer.
#
# The PR and auto-merge use the PAT in PKGS_BOT_TOKEN, because a merge made
# with the built-in GITHUB_TOKEN does not start publish.yml, and its pushes
# are held for approval instead of building.

on:
  schedule:
    # Every 6 hours, off the hour to dodge the scheduling backlog at :00
    - cron: '40 */6 * * *'
  workflow_dispatch:
    inputs:
      packages:
        description: 'Specific packages to update (space-separated, leave empty for all)'
        required: false
        default: ''

jobs:
  sync:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write

    steps:
      - name: Require the bot token
        env:
          PKGS_BOT_TOKEN: ${{ secrets.PKGS_BOT_TOKEN }}
        run: |
          if [[ -z "$PKGS_BOT_TOKEN" ]]; then
            echo "::error::Set PKGS_BOT_TOKEN to a PAT with Contents: write and Pull requests: write on this repository, owned by an account trusted to trigger builds."
            exit 1
          fi

      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          persist-credentials: false

      # A scoped dispatch regenerates only the named packages. Pushed to the
      # shared branch, that would replace every other pending update in its
      # PR, so it gets a branch and PR of its own.
      - name: Choose the PR branch
        id: branch
        env:
          PACKAGES: ${{ github.event.inputs.packages }}
        run: |
          read -r -a package_args <<< "${PACKAGES:-}"
          .github/scripts/sync-pr-branch.sh auto/sync-rebuilds "${package_args[@]}" | tee -a "$GITHUB_OUTPUT"

      # Runs in an Arch container against the mirror the x86_64 builder itself
      # uses, because the question being asked is what that builder will link
      # against and a different mirror can be hours ahead of it. Recording a
      # version the build never saw is the one failure this command must not
      # have: nothing re-fires once the record matches.
      - name: Bump pkgrel for packages whose dependencies moved
        run: |
          docker run --rm \
            -e PACKAGES="$PACKAGES" \
            -e HOST_UID="$(id -u)" \
            -e HOST_GID="$(id -g)" \
            -v "$PWD/bin:/workspace/bin:ro" \
            -v "$PWD/helpers:/workspace/helpers:ro" \
            -v "$PWD/pkgbuilds:/workspace/pkgbuilds" \
            -w /workspace \
            archlinux:base-devel bash -lc '
              set -euo pipefail

              printf "Server = https://mirror.omarchy.org/\$repo/os/\$arch\n" > /etc/pacman.d/mirrorlist
              pacman -Syu --noconfirm jq

              groupadd -g "$HOST_GID" runner
              useradd -m -u "$HOST_UID" -g "$HOST_GID" runner
              chown -R runner:runner /workspace/pkgbuilds

              if [[ -n "${PACKAGES:-}" ]]; then
                read -r -a package_args <<< "$PACKAGES"
                runuser -u runner -- ./bin/sync-rebuilds "${package_args[@]}"
              else
                runuser -u runner -- ./bin/sync-rebuilds
              fi
            '
        env:
          PACKAGES: ${{ github.event.inputs.packages }}

      - name: Check for changes
        id: changes
        run: |
          if [ -z "$(git status --porcelain)" ]; then
            echo "has_changes=false" >> "$GITHUB_OUTPUT"
          else
            echo "has_changes=true" >> "$GITHUB_OUTPUT"
          fi

      - name: Create Pull Request
        if: steps.changes.outputs.has_changes == 'true'
        id: cpr
        uses: peter-evans/create-pull-request@v7
        with:
          token: ${{ secrets.PKGS_BOT_TOKEN }}
          commit-message: 'chore: rebuild against updated dependencies'
          title: "chore: rebuild against updated dependencies${{ steps.branch.outputs.scope && format(' ({0})', steps.branch.outputs.scope) || '' }}"
          body: |
            Automated pkgrel bump for packages that link against a dependency
            which has moved in the official repositories.

            Each package names those dependencies in `rebuild_on` and carries the
            versions its current pkgrel was bumped for in `rebuilt_against`. The
            bump is what makes the rebuilt package an upgrade pacman will offer;
            without it the build produces the version already published and no
            one receives it.

            This PR auto-merges once the build checks pass. A failing rebuild
            leaves it open for a maintainer.
          branch: ${{ steps.branch.outputs.branch }}
          delete-branch: true
          labels: automated

      # Auto-merge, not a direct merge: branch protection still has to see
      # the build checks green before the rebuild lands.
      - name: Enable auto-merge
        if: steps.cpr.outputs.pull-request-number != ''
        env:
          GH_TOKEN: ${{ secrets.PKGS_BOT_TOKEN }}
          PR: ${{ steps.cpr.outputs.pull-request-number }}
        run: |
          # Idempotent across re-runs of an updated PR: enabling twice errors.
          if [[ "$(gh pr view "$PR" -R "${{ github.repository }}" --json autoMergeRequest --jq '.autoMergeRequest != null')" == true ]]; then
            echo "auto-merge already enabled on #$PR"
            exit 0
          fi
          gh pr merge --auto --merge "$PR" -R "${{ github.repository }}"

      - name: Notify Basecamp on failure
        if: failure() && env.BASECAMP_CHATBOT_URL != ''
        env:
          BASECAMP_CHATBOT_URL: ${{ secrets.BASECAMP_CHATBOT_URL }}
        run: |
          curl -s -o /dev/null \
            -H "Content-Type: application/json" \
            -d "$(jq -n --arg content \
              "🔴 <strong>Rebuild trigger sync failed</strong><br><a href=\"${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}\">View run</a>" \
              '{content: $content}')" \
            "$BASECAMP_CHATBOT_URL"