name: Sync upstream & merge-forward skill branches

on:
  # Triggered by upstream repo via repository_dispatch
  repository_dispatch:
    types: [upstream-main-updated]
  # Fallback: run on schedule in case dispatch isn't configured
  schedule:
    - cron: '0 */6 * * *'  # every 6 hours
  # Also run when fork's main is pushed directly
  push:
    branches: [main]
  workflow_dispatch:

permissions:
  contents: write
  issues: write

jobs:
  sync-and-merge:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
          token: ${{ secrets.GITHUB_TOKEN }}

      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: npm

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

      - name: Sync with upstream main
        id: sync
        run: |
          # Add upstream remote
          git remote add upstream https://github.com/qwibitai/nanoclaw.git
          git fetch upstream main

          # Check if upstream has new commits
          if git merge-base --is-ancestor upstream/main HEAD; then
            echo "Already up to date with upstream main."
            echo "synced=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          # Merge upstream main into fork's main
          if ! git merge upstream/main --no-edit; then
            echo "::error::Failed to merge upstream/main into fork main — conflicts detected"
            git merge --abort
            echo "synced=false" >> "$GITHUB_OUTPUT"
            echo "sync_failed=true" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          # Validate build
          npm ci
          if ! npm run build; then
            echo "::error::Build failed after merging upstream/main"
            git reset --hard "origin/main"
            echo "synced=false" >> "$GITHUB_OUTPUT"
            echo "sync_failed=true" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          if ! npm test 2>/dev/null; then
            echo "::error::Tests failed after merging upstream/main"
            git reset --hard "origin/main"
            echo "synced=false" >> "$GITHUB_OUTPUT"
            echo "sync_failed=true" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          git push origin main
          echo "synced=true" >> "$GITHUB_OUTPUT"

      - name: Merge main into skill branches
        id: merge
        run: |
          FAILED=""
          SUCCEEDED=""

          # List all remote skill branches
          SKILL_BRANCHES=$(git branch -r --list 'origin/skill/*' | sed 's|origin/||' | xargs)

          if [ -z "$SKILL_BRANCHES" ]; then
            echo "No skill branches found."
            exit 0
          fi

          for BRANCH in $SKILL_BRANCHES; do
            SKILL_NAME=$(echo "$BRANCH" | sed 's|skill/||')
            echo ""
            echo "=== Processing $BRANCH ==="

            git checkout -B "$BRANCH" "origin/$BRANCH"

            if ! git merge main --no-edit; then
              echo "::warning::Merge conflict in $BRANCH"
              git merge --abort
              FAILED="$FAILED $SKILL_NAME"
              continue
            fi

            # Check if there's anything new to push
            if git diff --quiet "origin/$BRANCH"; then
              echo "$BRANCH is already up to date with main."
              SUCCEEDED="$SUCCEEDED $SKILL_NAME"
              continue
            fi

            npm ci

            if ! npm run build; then
              echo "::warning::Build failed for $BRANCH"
              git reset --hard "origin/$BRANCH"
              FAILED="$FAILED $SKILL_NAME"
              continue
            fi

            if ! npm test 2>/dev/null; then
              echo "::warning::Tests failed for $BRANCH"
              git reset --hard "origin/$BRANCH"
              FAILED="$FAILED $SKILL_NAME"
              continue
            fi

            git push origin "$BRANCH"
            SUCCEEDED="$SUCCEEDED $SKILL_NAME"
            echo "$BRANCH merged and pushed successfully."
          done

          echo ""
          echo "=== Results ==="
          echo "Succeeded: $SUCCEEDED"
          echo "Failed: $FAILED"

          echo "failed=$FAILED" >> "$GITHUB_OUTPUT"
          echo "succeeded=$SUCCEEDED" >> "$GITHUB_OUTPUT"

      - name: Open issue for upstream sync failure
        if: steps.sync.outputs.sync_failed == 'true'
        uses: actions/github-script@v7
        with:
          script: |
            await github.rest.issues.create({
              owner: context.repo.owner,
              repo: context.repo.repo,
              title: `Upstream sync failed — merge conflict or build failure`,
              body: [
                'The automated sync with `qwibitai/nanoclaw` main failed.',
                '',
                'This usually means upstream made changes that conflict with this fork\'s channel code.',
                '',
                'To resolve manually:',
                '```bash',
                'git fetch upstream main',
                'git merge upstream/main',
                '# resolve conflicts',
                'npm run build && npm test',
                'git push',
                '```',
              ].join('\n'),
              labels: ['upstream-sync']
            });

      - name: Open issue for failed skill merges
        if: steps.merge.outputs.failed != ''
        uses: actions/github-script@v7
        with:
          script: |
            const failed = '${{ steps.merge.outputs.failed }}'.trim().split(/\s+/);
            const body = [
              `The merge-forward workflow failed to merge \`main\` into the following skill branches:`,
              '',
              ...failed.map(s => `- \`skill/${s}\`: merge conflict, build failure, or test failure`),
              '',
              'Please resolve manually:',
              '```bash',
              ...failed.map(s => [
                `git checkout skill/${s}`,
                `git merge main`,
                `# resolve conflicts, then: git push`,
                ''
              ]).flat(),
              '```',
            ].join('\n');

            await github.rest.issues.create({
              owner: context.repo.owner,
              repo: context.repo.repo,
              title: `Merge-forward failed for ${failed.length} skill branch(es)`,
              body,
              labels: ['skill-maintenance']
            });