import json
from typing import List, Dict, Any, Optional

from fastapi.encoders import jsonable_encoder

from schemas.reslevis import ZoneAreaDefinitionItem
from .config import ZONE_AREA_DEFINITION_JSON_PATH
from .gateway import _LockedFile, _atomic_write, _norm_str


class ZoneAreaDefinitionJsonRepository:
    def __init__(self, json_path: str = ZONE_AREA_DEFINITION_JSON_PATH):
        self.path = json_path

    def _read_all(self) -> List[Dict[str, Any]]:
        with _LockedFile(self.path, "r") as fp:
            try:
                fp.seek(0)
                data = fp.read().strip()
                return json.loads(data) if data else []
            except json.JSONDecodeError:
                return []

    def _write_all(self, rows: List[Dict[str, Any]]) -> None:
        payload = json.dumps(rows, ensure_ascii=False, indent=2)
        _atomic_write(self.path, payload)

    def _index_by_uuid(self, rows: List[Dict[str, Any]], item_uuid: str) -> Optional[int]:
        target = _norm_str(item_uuid)
        for idx, row in enumerate(rows):
            if _norm_str(row.get("UUID")) == target:
                return idx
        return None

    def list(self, item_uuid: Optional[str] = None) -> List[Dict[str, Any]]:
        rows = self._read_all()
        if item_uuid:
            idx = self._index_by_uuid(rows, item_uuid)
            return [rows[idx]] if idx is not None else []
        return rows

    def add(self, item: ZoneAreaDefinitionItem) -> None:
        rows = self._read_all()
        obj = jsonable_encoder(item)
        obj_uuid = _norm_str(obj.get("UUID"))

        if self._index_by_uuid(rows, obj_uuid) is not None:
            raise ValueError(f"ZoneAreaDefinition con UUID '{obj_uuid}' già presente")

        rows.append(obj)
        self._write_all(rows)

    def update(self, item: ZoneAreaDefinitionItem) -> None:
        rows = self._read_all()
        obj = jsonable_encoder(item)
        obj_uuid = _norm_str(obj.get("UUID"))

        idx = self._index_by_uuid(rows, obj_uuid)
        if idx is None:
            raise ValueError(f"ZoneAreaDefinition con UUID '{obj_uuid}' non trovato")

        rows[idx] = obj
        self._write_all(rows)

    def remove(self, item_uuid: str) -> None:
        rows = self._read_all()
        idx = self._index_by_uuid(rows, item_uuid)
        if idx is None:
            raise ValueError(f"ZoneAreaDefinition con UUID '{item_uuid}' non trovato")

        del rows[idx]
        self._write_all(rows)