sync-preview.yml

name: Sync Preview with Main

on:
  workflow_dispatch:
  push:
    branches: [main]

concurrency:
  group: sync-preview
  cancel-in-progress: false

permissions:
  contents: write
  pull-requests: write

jobs:
  sync:
    name: Merge main into preview
    runs-on: ubuntu-latest
    steps:
      - name: Generate GitHub App Token
        id: app-token
        uses: actions/create-github-app-token@v1
        with:
          app-id: ${{ vars.APP_ID }}
          private-key: ${{ secrets.APP_PRIVATE_KEY }}

      - name: Checkout preview
        uses: actions/checkout@v6
        with:
          ref: preview
          fetch-depth: 0
          token: ${{ steps.app-token.outputs.token }}

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

      - name: Check if sync needed
        id: check
        run: |
          git fetch origin main
          MAIN_SHA=$(git rev-parse origin/main)
          MERGE_BASE=$(git merge-base HEAD origin/main)

          if [[ "$MAIN_SHA" == "$MERGE_BASE" ]]; then
            echo "✅ preview already contains all of main"
            echo "needed=false" >> $GITHUB_OUTPUT
          else
            echo "needed=true" >> $GITHUB_OUTPUT
          fi

      - name: Skip if already synced
        if: steps.check.outputs.needed == 'false'
        run: echo "Nothing to sync."

      - name: Merge main into preview
        if: steps.check.outputs.needed == 'true'
        id: merge
        run: |
          # Save preview's version before merge so we can restore it after
          PREVIEW_VERSION=$(node -p "require('./package.json').version")
          echo "preview_version=$PREVIEW_VERSION" >> $GITHUB_OUTPUT

          if git merge origin/main --no-edit -m "chore: merge main into preview"; then
            echo "status=clean" >> $GITHUB_OUTPUT
          else
            # preview carries a higher version string than main (e.g. 1.0.0-preview.X vs 0.13.X).
            # This means package.json/package-lock.json almost always conflict on the version field.
            # Accept main's content here; the version is restored in the next step.
            for f in package.json package-lock.json; do
              if git diff --name-only --diff-filter=U | grep -qx "$f"; then
                git checkout --theirs "$f"
                git add "$f"
                echo "  ↳ resolved $f conflict (accepted main, will restore version)"
              fi
            done

            # Check if all conflicts are now resolved
            if [[ -z "$(git diff --name-only --diff-filter=U)" ]]; then
              git commit --no-edit -m "chore: merge main into preview"
              echo "status=clean" >> $GITHUB_OUTPUT
            else
              echo "status=conflict" >> $GITHUB_OUTPUT
            fi
          fi

      - name: Restore preview-owned files
        if: steps.merge.outputs.status == 'clean'
        run: |
          # These files are auto-generated during preview releases and must not
          # be overwritten by main's versions (schema-check CI will reject changes
          # to schemas/, and CHANGELOG.md tracks preview releases separately).
          PREVIEW_HEAD=$(git rev-parse HEAD^1)
          for f in schemas/agentcore.schema.v1.json CHANGELOG.md; do
            if git show "$PREVIEW_HEAD:$f" > /dev/null 2>&1; then
              git show "$PREVIEW_HEAD:$f" > "$f"
              git add "$f"
              echo "  ↳ restored preview's $f"
            fi
          done
          if ! git diff --cached --quiet; then
            git commit -m "chore: restore preview-owned files (schema, changelog)"
          fi

      - name: Restore preview version and push
        if: steps.merge.outputs.status == 'clean'
        run: |
          PREVIEW_VERSION="${{ steps.merge.outputs.preview_version }}"
          CURRENT_VERSION=$(node -p "require('./package.json').version")

          if [[ "$CURRENT_VERSION" != "$PREVIEW_VERSION" ]]; then
            PREVIEW_VERSION="$PREVIEW_VERSION" node -e "
              const fs = require('fs');
              const pkg = JSON.parse(fs.readFileSync('package.json', 'utf8'));
              pkg.version = process.env.PREVIEW_VERSION;
              fs.writeFileSync('package.json', JSON.stringify(pkg, null, 2) + '\n');
            "
            if [[ -f package-lock.json ]]; then
              PREVIEW_VERSION="$PREVIEW_VERSION" node -e "
                const fs = require('fs');
                const lock = JSON.parse(fs.readFileSync('package-lock.json', 'utf8'));
                lock.version = process.env.PREVIEW_VERSION;
                if (lock.packages && lock.packages['']) {
                  lock.packages[''].version = process.env.PREVIEW_VERSION;
                }
                fs.writeFileSync('package-lock.json', JSON.stringify(lock, null, 2) + '\n');
              "
            fi
            git add package.json
            [[ -f package-lock.json ]] && git add package-lock.json
            git commit -m "chore: restore preview version ($PREVIEW_VERSION)"
          fi

          git push origin HEAD:preview
          echo "✅ main merged into preview and pushed"

      - name: Create PR for conflict resolution
        if: steps.merge.outputs.status == 'conflict'
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}
        run: |
          # Check if there's already an open sync PR (match by branch prefix, not title search)
          COUNT=$(gh pr list --base preview --state open --json headRefName \
            --jq '[.[] | select(.headRefName | startswith("sync-preview/"))] | length')
          if [[ "$COUNT" != "0" ]]; then
            echo "ℹ️  Sync PR already open — skipping duplicate."
            exit 0
          fi

          # Abort the failed merge and redo on a branch for the PR
          git merge --abort

          BRANCH="sync-preview/merge-main-$(date +%Y%m%d-%H%M%S)"
          git checkout -b "$BRANCH"
          git merge origin/main --no-edit -m "chore: merge main into preview (conflicts need resolution)" || true
          git add -A
          git commit --no-edit -m "chore: merge main into preview (conflicts need resolution)" || true
          git push origin "$BRANCH"

          GH_USER=$(gh api "/repos/${{ github.repository }}/commits/$(git rev-parse origin/main)" --jq '.author.login // empty' 2>/dev/null || echo "")
          MENTION=""
          if [[ -n "$GH_USER" ]]; then
            MENTION="cc @${GH_USER}"
          fi

          gh pr create \
            --base preview \
            --head "$BRANCH" \
            --title "sync-preview: merge main into preview (conflicts)" \
            --body "$(cat <<BODY
          The automated sync could not cleanly merge \`main\` into \`preview\`.

          **This PR contains conflict markers.** To resolve:

          1. Check out this branch locally:
             \`\`\`bash
             gh pr checkout <this-pr-number>
             \`\`\`
          2. Search for conflict markers and resolve them:
             \`\`\`bash
             grep -rn '<<<<<<< HEAD' .
             \`\`\`
          3. Keep preview-specific values (package version, preview tests, etc.) — accept main's changes for everything else.
          4. Commit and push, then merge this PR.

          ${MENTION}

          _Opened automatically by the sync-preview workflow._
          BODY
          )"