#!/usr/bin/env python3
"""
backlog_triage.py — Weekly backlog health check for timmy-home.

Queries Gitea API for open issues and reports:
- Unassigned issues
- Issues with no labels
- Batch-pipeline issues (triaged with comments)

Usage:
    python scripts/backlog_triage.py [--token TOKEN] [--repo OWNER/REPO]

Exit codes:
    0 = backlog healthy (no action needed)
    1 = issues found requiring attention
"""

import argparse
import json
import os
import sys
from datetime import datetime, timezone
from urllib.request import Request, urlopen
from urllib.error import URLError

GITEA_BASE = os.environ.get("GITEA_BASE_URL", "https://forge.alexanderwhitestone.com/api/v1")


def fetch_issues(owner: str, repo: str, token: str, state: str = "open") -> list:
    """Fetch all open issues from Gitea."""
    issues = []
    page = 1
    per_page = 50

    while True:
        url = f"{GITEA_BASE}/repos/{owner}/{repo}/issues?state={state}&page={page}&per_page={per_page}&type=issues"
        req = Request(url)
        req.add_header("Authorization", f"token {token}")

        try:
            with urlopen(req) as resp:
                batch = json.loads(resp.read())
        except URLError as e:
            print(f"ERROR: Failed to fetch issues: {e}", file=sys.stderr)
            sys.exit(2)

        if not batch:
            break

        issues.extend(batch)
        page += 1

    return issues


def categorize_issues(issues: list) -> dict:
    """Categorize issues into triage buckets."""
    unassigned = []
    no_labels = []
    batch_pipeline = []

    for issue in issues:
        # Skip pull requests (Gitea includes them in issues endpoint)
        if "pull_request" in issue:
            continue

        number = issue["number"]
        title = issue["title"]
        assignee = issue.get("assignee")
        labels = issue.get("labels", [])

        if not assignee:
            unassigned.append({"number": number, "title": title})

        if not labels:
            no_labels.append({"number": number, "title": title})

        if "batch-pipeline" in title.lower() or any(
            lbl.get("name", "").lower() == "batch-pipeline" for lbl in labels
        ):
            batch_pipeline.append({"number": number, "title": title})

    return {
        "unassigned": unassigned,
        "no_labels": no_labels,
        "batch_pipeline": batch_pipeline,
    }


def print_report(owner: str, repo: str, categories: dict) -> int:
    """Print triage report and return count of issues needing attention."""
    now = datetime.now(timezone.utc).strftime("%Y-%m-%d %H:%M UTC")
    print(f"# Backlog Triage Report — {owner}/{repo}")
    print(f"Generated: {now}\n")

    total_attention = 0

    # Unassigned
    print(f"## Unassigned Issues ({len(categories['unassigned'])})")
    if categories["unassigned"]:
        total_attention += len(categories["unassigned"])
        for item in categories["unassigned"]:
            print(f"  - #{item['number']}: {item['title']}")
    else:
        print("  ✓ None")
    print()

    # No labels
    print(f"## Issues with No Labels ({len(categories['no_labels'])})")
    if categories["no_labels"]:
        total_attention += len(categories["no_labels"])
        for item in categories["no_labels"]:
            print(f"  - #{item['number']}: {item['title']}")
    else:
        print("  ✓ None")
    print()

    # Batch-pipeline
    print(f"## Batch-Pipeline Issues ({len(categories['batch_pipeline'])})")
    if categories["batch_pipeline"]:
        for item in categories["batch_pipeline"]:
            print(f"  - #{item['number']}: {item['title']}")
    else:
        print("  ✓ None")
    print()

    print(f"---\nTotal issues requiring attention: {total_attention}")
    return total_attention


def main():
    parser = argparse.ArgumentParser(description="Weekly backlog triage for timmy-home")
    parser.add_argument("--token", default=os.environ.get("GITEA_TOKEN", ""),
                        help="Gitea API token (or set GITEA_TOKEN env)")
    parser.add_argument("--repo", default="Timmy_Foundation/timmy-home",
                        help="Repository in OWNER/REPO format")
    args = parser.parse_args()

    if not args.token:
        print("ERROR: No Gitea token provided. Set GITEA_TOKEN or use --token.", file=sys.stderr)
        sys.exit(2)

    owner, repo = args.repo.split("/", 1)

    issues = fetch_issues(owner, repo, args.token)
    categories = categorize_issues(issues)
    needs_attention = print_report(owner, repo, categories)

    sys.exit(1 if needs_attention > 0 else 0)


if __name__ == "__main__":
    main()