# ============================================================
# MES 集成桩（moduleId: integ-mes-stub, 可重生 ✅）
# EX-05/09 最小切片：进程内 Mock MES，无真实车间接口。
# 下发：创建外部工单（幂等）；报工：进度/完工回写镜像。
# ============================================================
from __future__ import annotations

import json
from datetime import datetime
from pathlib import Path
from typing import Any

_MIRROR_PATH = Path(__file__).resolve().parents[1] / "data" / "mes_mirror.json"


def default_mirror() -> dict[str, Any]:
    return {
        "system": "MES-MOCK",
        "plant": "CNWH",
        "updatedAt": datetime.now().strftime("%Y-%m-%d %H:%M"),
        "workOrders": [],       # 外部工单
        "reports": [],          # 报工流水
        "idempotency": {},      # key → externalWoId
    }


class MockMesClient:
    """进程内 Mock MES：读写本地镜像，模拟下发与报工。"""

    def __init__(self, path: Path | None = None):
        self.path = path or _MIRROR_PATH
        self.path.parent.mkdir(parents=True, exist_ok=True)
        if not self.path.exists():
            self._save(default_mirror())

    def _load(self) -> dict:
        try:
            return json.loads(self.path.read_text(encoding="utf-8"))
        except (OSError, json.JSONDecodeError):
            data = default_mirror()
            self._save(data)
            return data

    def _save(self, data: dict) -> None:
        data["updatedAt"] = datetime.now().strftime("%Y-%m-%d %H:%M")
        self.path.write_text(json.dumps(data, ensure_ascii=False, indent=2), encoding="utf-8")

    def status(self) -> dict:
        m = self._load()
        wos = m.get("workOrders") or []
        return {
            "connected": True,
            "mode": "stub",
            "system": m.get("system"),
            "plant": m.get("plant"),
            "updatedAt": m.get("updatedAt"),
            "woCount": len(wos),
            "openCount": sum(1 for w in wos if w.get("status") != "COMPLETED"),
            "reportCount": len(m.get("reports") or []),
        }

    def create_work_order(self, payload: dict, idem_key: str) -> dict:
        """幂等下发：相同 idem_key 返回原外部工单。"""
        m = self._load()
        existing = (m.get("idempotency") or {}).get(idem_key)
        if existing:
            wo = next((w for w in m.get("workOrders", []) if w["id"] == existing), None)
            return {"duplicate": True, "externalWo": wo or {"id": existing, "idemKey": idem_key}}
        eid = f"MES-WO-{len(m.get('workOrders') or []) + 1:04d}"
        external = {
            "id": eid, "idemKey": idem_key, "plant": m.get("plant"),
            "at": datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
            "status": "RELEASED", "qtyDone": 0, "progressPct": 0,
            **payload,
        }
        m.setdefault("workOrders", []).append(external)
        m.setdefault("idempotency", {})[idem_key] = eid
        self._save(m)
        return {"duplicate": False, "externalWo": external}

    def post_report(self, external_wo_id: str, payload: dict) -> dict:
        """写入报工流水并更新外部工单进度。"""
        m = self._load()
        wo = next((w for w in m.get("workOrders", []) if w["id"] == external_wo_id), None)
        if not wo:
            raise ValueError(f"MES 无外部工单 {external_wo_id}")
        rid = f"MES-RPT-{len(m.get('reports') or []) + 1:04d}"
        report = {
            "id": rid, "externalWoId": external_wo_id,
            "at": datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
            **payload,
        }
        m.setdefault("reports", []).append(report)
        if "qtyDone" in payload:
            wo["qtyDone"] = payload["qtyDone"]
        if "progressPct" in payload:
            wo["progressPct"] = payload["progressPct"]
        if payload.get("status"):
            wo["status"] = payload["status"]
        self._save(m)
        return {"report": report, "externalWo": wo}

    def reset(self) -> dict:
        data = default_mirror()
        self._save(data)
        return self.status()


_client: MockMesClient | None = None


def get_mes_client() -> MockMesClient:
    global _client
    if _client is None:
        _client = MockMesClient()
    return _client


def reset_mes_client(path: Path | None = None) -> MockMesClient:
    global _client
    _client = MockMesClient(path)
    _client.reset()
    return _client