name: Watch Mihomo Meta

on:
  schedule:
    - cron: "0 */6 * * *"
  workflow_dispatch: {}

permissions:
  contents: write

concurrency:
  group: watch-mihomo-meta-dev
  cancel-in-progress: false

env:
  # Scheduled workflows run from the default branch, but the marker belongs to dev.
  TARGET_BRANCH: dev
  MIHOMO_REPO: https://github.com/MetaCubeX/mihomo.git
  MARKER_FILE: .github/mihomo-meta.rev

jobs:
  watch:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout target branch
        uses: actions/checkout@v6
        with:
          ref: ${{ env.TARGET_BRANCH }}
          fetch-depth: 0
          token: ${{ secrets.PAT_TOKEN || github.token }}

      - name: Check Meta updates
        run: |
          set -euo pipefail

          echo "Workflow ref: ${GITHUB_REF}"
          echo "Tracking Meta revision on ${TARGET_BRANCH}"

          latest=$(git ls-remote "$MIHOMO_REPO" Meta | awk '{print $1}')
          if [ -z "$latest" ]; then
            echo "Failed to resolve Meta HEAD"
            exit 1
          fi

          prev=""
          if [ -f "$MARKER_FILE" ]; then
            prev=$(tr -d '[:space:]' < "$MARKER_FILE")
          fi

          if [ "$latest" = "$prev" ]; then
            echo "No upstream changes."
            exit 0
          fi

          tmp=$(mktemp -d)
          trap 'rm -rf "$tmp"' EXIT
          git -C "$tmp" init -q
          git -C "$tmp" remote add origin "$MIHOMO_REPO"
          git -C "$tmp" fetch --no-tags --depth=2000 origin Meta

          if [ -n "$prev" ] && ! git -C "$tmp" cat-file -e "${prev}^{commit}"; then
            git -C "$tmp" fetch --no-tags --unshallow origin Meta || git -C "$tmp" fetch --no-tags origin Meta
          fi

          touched=""
          if [ -n "$prev" ] && git -C "$tmp" merge-base --is-ancestor "$prev" "$latest"; then
            touched=$(git -C "$tmp" log --name-only --pretty="" "$prev..$latest" -- \
              common/convert/converter.go \
              adapter/outbound/base.go \
              adapter/outbound | sort -u | sed '/^$/d' || true)
          else
            touched="unknown"
          fi

          printf '%s\n' "$latest" > "$MARKER_FILE"

          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git add "$MARKER_FILE"

          if [ "$touched" = "unknown" ]; then
            msg="chore(mihomo): update Meta revision"
          elif [ -n "$touched" ]; then
            msg="chore(mihomo): update Meta revision"
          else
            msg="chore(mihomo): update Meta revision [skip ci]"
          fi

          git commit -m "$msg" || exit 0

          git fetch --no-tags origin "refs/heads/$TARGET_BRANCH:refs/remotes/origin/$TARGET_BRANCH"
          git rebase "origin/$TARGET_BRANCH"
          git push origin "HEAD:refs/heads/$TARGET_BRANCH"