sync-upstream.yml

name: Sync Fork With Upstream

on:
  schedule:
    - cron: '0 7 * * *' # Every day at 07:00 UTC
  workflow_dispatch:
    inputs:
      upstream_branch:
        description: 'Upstream branch to sync from (default: main)'
        required: false
        default: 'main'
        type: string

permissions:
  contents: write
  pull-requests: write

concurrency:
  group: sync-upstream-${{ github.repository }}
  cancel-in-progress: true

jobs:
  sync:
    runs-on: ubuntu-latest
    env:
      UPSTREAM_REPO: https://github.com/garrytan/gstack.git
      UPSTREAM_BRANCH: ${{ inputs.upstream_branch || 'main' }}
      SYNC_BRANCH: sync/upstream-main
      BASE_BRANCH: ${{ github.event.repository.default_branch }}

    steps:
      - name: Checkout fork repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Configure Git identity
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"

      - name: Fetch upstream and push sync branch
        run: |
          git remote add upstream "$UPSTREAM_REPO" || git remote set-url upstream "$UPSTREAM_REPO"
          git fetch upstream "$UPSTREAM_BRANCH"
          git checkout -B "$SYNC_BRANCH" "upstream/$UPSTREAM_BRANCH"
          git push origin "$SYNC_BRANCH" --force

      - name: Create or update sync PR
        uses: actions/github-script@v7
        with:
          script: |
            const owner = context.repo.owner;
            const repo = context.repo.repo;
            const head = `${owner}:${process.env.SYNC_BRANCH}`;
            const base = process.env.BASE_BRANCH || 'main';
            const labels = ['upstream-sync', 'dependencies'];

            const compare = await github.rest.repos.compareCommitsWithBasehead({
              owner,
              repo,
              basehead: `${base}...${process.env.SYNC_BRANCH}`
            });

            if (compare.data.total_commits === 0) {
              core.info(`No new commits to sync from upstream into ${base}.`);
              return;
            }

            const open = await github.rest.pulls.list({
              owner,
              repo,
              state: 'open',
              head,
              base
            });

            if (open.data.length > 0) {
              const pr = open.data[0];
              await github.rest.issues.addLabels({
                owner,
                repo,
                issue_number: pr.number,
                labels
              });
              await github.rest.pulls.update({
                owner,
                repo,
                pull_number: pr.number,
                title: `chore: sync upstream (${process.env.UPSTREAM_BRANCH} -> ${base})`
              });
              core.info(`Sync PR already exists: #${pr.number}`);
              return;
            }

            const created = await github.rest.pulls.create({
              owner,
              repo,
              title: `chore: sync upstream (${process.env.UPSTREAM_BRANCH} -> ${base})`,
              head: process.env.SYNC_BRANCH,
              base,
              body: [
                'Automated upstream sync PR.',
                '',
                `- Upstream: ${process.env.UPSTREAM_REPO}`,
                `- Upstream branch: ${process.env.UPSTREAM_BRANCH}`,
                `- Base branch: ${base}`,
                '',
                'Please review and merge when checks pass.'
              ].join('\n')
            });

            await github.rest.issues.addLabels({
              owner,
              repo,
              issue_number: created.data.number,
              labels
            });

            core.info(`Created PR #${created.data.number}: ${created.data.html_url}`);