Firebase Preview Channel Clean Up

name: Firebase Preview Channels Cleanup

on:
  workflow_dispatch:        # manual trigger only
    inputs:
      delete_closed:
        description: 'Delete channels whose PR is closed/merged'
        type: boolean
        default: false
  schedule:
    - cron: '0 1 * * 5'     # Friday 09:00 HKT (01:00 UTC) — auto-delete merged/closed

permissions:
  contents: read
  pull-requests: read

jobs:
  list-channels:
    runs-on: ubuntu-latest
    env:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      DELETE_CLOSED: ${{ inputs.delete_closed }}
    steps:
      - name: Checkout
        uses: actions/checkout@v5

      - name: Setup Node
        uses: actions/setup-node@v4
        with:
          node-version: '20'

      - name: Install Firebase CLI
        run: npm install -g firebase-tools

      - name: Authenticate to Firebase
        run: |
          echo '${{ secrets.FIREBASE_SERVICE_ACCOUNT }}' > "$RUNNER_TEMP/sa.json"
          echo "GOOGLE_APPLICATION_CREDENTIALS=$RUNNER_TEMP/sa.json" >> "$GITHUB_ENV"
          PROJECT_ID=$(python3 -c "import json;print(json.load(open('$RUNNER_TEMP/sa.json'))['project_id'])")
          echo "FIREBASE_PROJECT=$PROJECT_ID" >> "$GITHUB_ENV"
          echo "Using Firebase project: $PROJECT_ID"          

      - name: List preview channels (channel, PR id, expire date)
        run: |
          echo "Project: $FIREBASE_PROJECT"
          echo "Creds present: $(test -s "$GOOGLE_APPLICATION_CREDENTIALS" && echo yes || echo no)"
          firebase --version

          # --json writes errors to stdout too, so don't blindly trust exit + redirect
          if ! firebase hosting:channel:list \
                --project "$FIREBASE_PROJECT" \
                --json > channels.json 2> fb_err.txt; then
            echo "::error::firebase hosting:channel:list failed"
            echo "--- stderr ---"; cat fb_err.txt
            echo "--- channels.json (may hold the JSON error) ---"; cat channels.json
            exit 1
          fi

          python3 - <<'PY'
          import json, datetime, re, os, subprocess

          repo = os.environ.get("GITHUB_REPOSITORY", "")

          _status_cache = {}
          def pr_status(pr):
              # open | merged | closed | not-found | unknown
              if pr in _status_cache:
                  return _status_cache[pr]
              status = "unknown"
              if repo:
                  try:
                      out = subprocess.run(
                          ["gh", "api", f"repos/{repo}/pulls/{pr}",
                           "--jq", "[.state, (.merged_at // \"\")] | @tsv"],
                          capture_output=True, text=True, timeout=30,
                      )
                      if out.returncode == 0:
                          state, merged_at = (out.stdout.strip().split("\t") + [""])[:2]
                          status = "merged" if merged_at else state
                      else:
                          status = "not-found"
                  except Exception:
                      status = "unknown"
              _status_cache[pr] = status
              return status

          with open("channels.json") as f:
              data = json.load(f)

          result = data.get("result", data)
          channels = result.get("channels", result) if isinstance(result, dict) else result
          if isinstance(channels, dict):
              channels = channels.get("channels", [])

          rows = []
          now = datetime.datetime.now(datetime.timezone.utc)

          for ch in channels:
              name = ch.get("name", "")
              channel_id = name.rsplit("/", 1)[-1] if name else ch.get("channelId", "")
              expire = ch.get("expireTime", "")
              url = ch.get("url", "")

              m = re.match(r"pr[-_]?(\d+)(?:[-_]|$)", channel_id, re.IGNORECASE)
              pr_id = m.group(1) if m else ""

              days_left = ""
              if expire:
                  try:
                      exp_dt = datetime.datetime.fromisoformat(expire.replace("Z", "+00:00"))
                      days_left = str((exp_dt - now).days)
                  except ValueError:
                      pass

              rows.append({
                  "channel": channel_id,
                  "pr": pr_id or "-",
                  "status": pr_status(pr_id) if pr_id else "-",
                  "expire": expire or "never",
                  "days_left": days_left or "-",
                  "url": url,
              })

          rows.sort(key=lambda r: (r["pr"] == "-", r["expire"]))

          print(f'{"CHANNEL":<22}{"PR":<8}{"STATUS":<11}{"DAYS LEFT":<12}{"EXPIRES":<28}URL')
          print("-" * 120)
          for r in rows:
              print(f'{r["channel"]:<22}{r["pr"]:<8}{r["status"]:<11}{r["days_left"]:<12}{r["expire"]:<28}{r["url"]}')

          if not rows:
              print("No preview channels found.")
          PY          

      - name: Delete channels for closed/merged PRs
        if: ${{ inputs.delete_closed || github.event_name == 'schedule' }}
        run: |
          # Extract PR-style channel ids and their PR numbers from channels.json
          python3 - <<'PY' > to_check.txt
          import json, re

          with open("channels.json") as f:
              data = json.load(f)

          result = data.get("result", data)
          channels = result.get("channels", result) if isinstance(result, dict) else result
          if isinstance(channels, dict):
              channels = channels.get("channels", [])

          for ch in channels:
              name = ch.get("name", "")
              channel_id = name.rsplit("/", 1)[-1] if name else ch.get("channelId", "")
              m = re.match(r"pr[-_]?(\d+)(?:[-_]|$)", channel_id, re.IGNORECASE)
              if m:
                  print(f"{channel_id}\t{m.group(1)}")
          PY

          if [ ! -s to_check.txt ]; then
            echo "No PR-style channels found to evaluate."
            exit 0
          fi

          while IFS=$'\t' read -r channel pr; do
            # GitHub API .state is only "open"|"closed"; merged PRs are "closed" with merged_at set.
            read -r state merged_at < <(
              gh api "repos/${GITHUB_REPOSITORY}/pulls/${pr}" \
                --jq '[.state, (.merged_at // "")] | @tsv' 2>/dev/null || echo "notfound"
            )

            if [ "$state" = "closed" ]; then
              label=$([ -n "$merged_at" ] && echo merged || echo closed)
              echo "PR #${pr} is ${label} -> deleting channel '${channel}'"
              firebase hosting:channel:delete "$channel" \
                --project "$FIREBASE_PROJECT" \
                --force
            elif [ "$state" = "open" ]; then
              echo "PR #${pr} is open -> keeping channel '${channel}'"
            else
              echo "PR #${pr} not found (state=${state}) -> skipping channel '${channel}' (review manually)"
            fi
          done < to_check.txt