name: PR Title Check

on:
  pull_request_target:
    types: [opened, edited, reopened, synchronize]

jobs:
  title-format:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
      issues: write

    steps:
      - name: Validate PR title
        uses: actions/github-script@v8
        with:
          script: |
            const title = (context.payload.pull_request.title || "").trim();
            // allow only:
            // feat: xxx
            // feat(scope): xxx
            const pattern = /^(feat)(\([a-z0-9-]+\))?:\s.+$/i;
            const isValid = pattern.test(title);
            const isSameRepo =
              context.payload.pull_request.head.repo.full_name === context.payload.repository.full_name;

            if (!isValid) {
              if (isSameRepo) {
                try {
                  await github.rest.issues.createComment({
                    owner: context.repo.owner,
                    repo: context.repo.repo,
                    issue_number: context.payload.pull_request.number,
                    body: [
                      "⚠️ PR title format check failed.",
                      "Required formats:",
                      "- `feat: xxx`",
                      "- `feat(scope): xxx`",
                      "Please update your PR title and push again."
                    ].join("\n")
                  });
                } catch (e) {
                  core.warning(`Failed to post PR title comment: ${e.message}`);
                }
              } else {
                core.warning("Fork PR: comment permission is restricted; skip posting review comment.");
              }
            }

            if (!isValid) {
              core.setFailed("Invalid PR title. Expected format: feat: xxx or feat(scope): xxx.");
            }