#!/usr/bin/env python3
"""Read-only PChome mapping backlog reporter with production version guard."""

from __future__ import annotations

import argparse
import json
import sys
import urllib.parse
import urllib.request
from pathlib import Path
from typing import Any


ROOT = Path(__file__).resolve().parents[2]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from scripts.ops import check_production_version_truth as version_guard  # noqa: E402
from services.pchome_mapping_backlog_service import summarize_pchome_mapping_backlog  # noqa: E402


DEFAULT_API_URL = "https://mo.wooo.work/api/ai/pchome-growth/opportunities"
DEFAULT_HEALTH_URL = "https://mo.wooo.work/health"


def with_limit(url: str, limit: int) -> str:
    """Add a clamped limit while preserving existing query parameters."""
    parsed = urllib.parse.urlsplit(url)
    query = urllib.parse.parse_qsl(parsed.query, keep_blank_values=True)
    query = [(key, value) for key, value in query if key != "limit"]
    query.append(("limit", str(max(5, min(int(limit or 20), 50)))))
    return urllib.parse.urlunsplit((
        parsed.scheme,
        parsed.netloc,
        parsed.path,
        urllib.parse.urlencode(query),
        parsed.fragment,
    ))


def fetch_json(url: str, timeout: float) -> dict[str, Any]:
    request = urllib.request.Request(
        url,
        headers={"Accept": "application/json", "User-Agent": "ewoooc-pchome-backlog-report/1"},
    )
    with urllib.request.urlopen(request, timeout=timeout) as response:
        payload = json.loads(response.read().decode("utf-8"))
    if not isinstance(payload, dict):
        raise ValueError("growth API payload must be a JSON object")
    return payload


def summarize_payload(payload: dict[str, Any]) -> dict[str, Any]:
    return summarize_pchome_mapping_backlog(payload)


def build_report(
    *,
    api_url: str,
    limit: int,
    timeout: float,
    health_url: str,
    skip_version_truth: bool,
    allow_local_version_drift: bool = False,
) -> dict[str, Any]:
    target_url = with_limit(api_url, limit)
    guard_report = None
    if not skip_version_truth:
        try:
            guard_report = version_guard.build_report(health_url, timeout)
            guard_ok, guard_errors = version_guard.evaluate(
                guard_report,
                allow_local_version_drift=allow_local_version_drift,
            )
        except Exception as error:
            return {
                "policy": "read_only_production_pchome_mapping_backlog",
                "result": "BLOCKED",
                "api_url": target_url,
                "errors": [f"production version truth unavailable: {error}"],
            }
        if not guard_ok:
            return {
                "policy": "read_only_production_pchome_mapping_backlog",
                "result": "BLOCKED",
                "api_url": target_url,
                "version_truth": guard_report,
                "errors": guard_errors,
            }

    try:
        summary = summarize_payload(fetch_json(target_url, timeout))
    except Exception as error:
        return {
            "policy": "read_only_production_pchome_mapping_backlog",
            "result": "BLOCKED",
            "api_url": target_url,
            "version_truth": guard_report,
            "errors": [f"growth API readback unavailable: {error}"],
        }

    return {
        **summary,
        "policy": "read_only_production_pchome_mapping_backlog",
        "api_url": target_url,
        "version_truth": guard_report,
        "errors": [],
    }


def _render_text(payload: dict[str, Any]) -> str:
    stats = payload.get("stats") or {}
    backlog = payload.get("backlog") or {}
    errors = payload.get("errors") or []
    if errors:
        return "\n".join([f"result={payload.get('result', 'BLOCKED')}", *errors])
    return "\n".join([
        f"result={payload.get('result', 'UNKNOWN')}",
        f"mapping_rate={stats.get('mapping_rate', 0)}%",
        f"needs_mapping={stats.get('needs_mapping_count', 0)}",
        f"direct_mapping={backlog.get('direct_mapping_count', 0)}",
        f"review_candidates={backlog.get('review_candidate_count', 0)}",
    ])


def main(argv: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description="輸出正式 PChome 商品對應 backlog。")
    parser.add_argument("--api-url", default=DEFAULT_API_URL)
    parser.add_argument("--health-url", default=DEFAULT_HEALTH_URL)
    parser.add_argument("--limit", type=int, default=20)
    parser.add_argument("--timeout", type=float, default=12.0)
    parser.add_argument("--skip-version-truth", action="store_true")
    parser.add_argument("--allow-local-version-drift", action="store_true")
    parser.add_argument("--json", action="store_true")
    args = parser.parse_args(argv)

    payload = build_report(
        api_url=args.api_url,
        limit=args.limit,
        timeout=args.timeout,
        health_url=args.health_url,
        skip_version_truth=args.skip_version_truth,
        allow_local_version_drift=args.allow_local_version_drift,
    )
    if args.json:
        print(json.dumps(payload, ensure_ascii=False, indent=2, sort_keys=True))
    else:
        print(_render_text(payload))
    return 1 if payload.get("result") == "BLOCKED" else 0


if __name__ == "__main__":
    raise SystemExit(main())