name: Sync Labels

on:
  workflow_dispatch:
  push:
    paths:
      - ".github/labels.yml"

permissions:
  contents: read
  issues: write

jobs:
  sync:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.11"

      - name: Install dependencies
        run: python -m pip install --disable-pip-version-check pyyaml

      - name: Sync labels
        env:
          GITHUB_TOKEN: ${{ github.token }}
          GITHUB_REPOSITORY: ${{ github.repository }}
        run: |
          python - <<'PY'
          import json
          import os
          import urllib.error
          import urllib.parse
          import urllib.request

          import yaml

          token = os.environ["GITHUB_TOKEN"]
          owner_repo = os.environ["GITHUB_REPOSITORY"]
          base_url = f"https://api.github.com/repos/{owner_repo}"

          with open(".github/labels.yml", "r", encoding="utf-8") as fh:
              config = yaml.safe_load(fh) or {}

          desired_labels = config.get("labels", [])
          desired_by_name = {label["name"]: label for label in desired_labels}

          headers = {
              "Accept": "application/vnd.github+json",
              "Authorization": f"Bearer {token}",
              "X-GitHub-Api-Version": "2022-11-28",
              "User-Agent": "mirofish-label-sync",
          }

          def request(method, url, payload=None):
              data = None
              if payload is not None:
                  data = json.dumps(payload).encode("utf-8")
              req = urllib.request.Request(url, data=data, headers=headers, method=method)
              with urllib.request.urlopen(req) as response:
                  raw = response.read()
                  return json.loads(raw.decode("utf-8")) if raw else None

          existing = []
          page = 1
          while True:
              url = f"{base_url}/labels?per_page=100&page={page}"
              batch = request("GET", url)
              if not batch:
                  break
              existing.extend(batch)
              if len(batch) < 100:
                  break
              page += 1

          existing_by_name = {label["name"]: label for label in existing}

          for name, desired in desired_by_name.items():
              payload = {
                  "new_name": desired["name"],
                  "color": desired["color"],
                  "description": desired["description"],
              }
              if name in existing_by_name:
                  url = f"{base_url}/labels/{urllib.parse.quote(name, safe='')}"
                  request("PATCH", url, payload)
                  print(f"updated {name}")
              else:
                  url = f"{base_url}/labels"
                  request("POST", url, {
                      "name": desired["name"],
                      "color": desired["color"],
                      "description": desired["description"],
                  })
                  print(f"created {name}")

          for name in sorted(existing_by_name):
              if name not in desired_by_name:
                  url = f"{base_url}/labels/{urllib.parse.quote(name, safe='')}"
                  try:
                      request("DELETE", url)
                      print(f"deleted {name}")
                  except urllib.error.HTTPError as exc:
                      raise RuntimeError(f"Failed to delete label '{name}': {exc.read().decode('utf-8')}") from exc
          PY