import json
from typing import Any

import httpx

from app.core.config import settings
from app.domain.schemas.place_search import PlaceSearchItem, ReverseGeocodingRequest
from app.domain.schemas.project_map_config import PlaceSearchConfig
from app.services.place_search import PlaceSearchError, PlaceSearchScopeError, validate_place_scope


async def reverse_geocode_tianditu(
    request: ReverseGeocodingRequest,
    *,
    config: PlaceSearchConfig,
    client: httpx.AsyncClient | None = None,
) -> PlaceSearchItem:
    if not config.enabled:
        raise PlaceSearchError(503, "当前项目暂未配置地名搜索")
    if not settings.TIANDITU_TOKEN:
        raise PlaceSearchError(503, "地名搜索服务未配置")
    params = {
        "postStr": json.dumps({"lon": request.longitude, "lat": request.latitude, "ver": 1}),
        "type": "geocode",
        "tk": settings.TIANDITU_TOKEN,
    }
    try:
        if client is not None:
            response = await client.get(settings.TIANDITU_GEOCODER_URL, params=params)
        else:
            async with httpx.AsyncClient(timeout=settings.TIANDITU_SEARCH_TIMEOUT_SECONDS) as managed:
                response = await managed.get(settings.TIANDITU_GEOCODER_URL, params=params)
        response.raise_for_status()
    except httpx.TimeoutException:
        raise PlaceSearchError(504, "地图取点查询超时，请重新取点") from None
    except httpx.HTTPError:
        raise PlaceSearchError(502, "天地图反编码服务暂不可用，请重新取点") from None
    try:
        return _parse_reverse_response(response.json(), request, config)
    except PlaceSearchScopeError:
        raise PlaceSearchError(422, f"取点位置不在当前项目的地名搜索范围内（{config.region}）") from None
    except (ValueError, TypeError, KeyError, AttributeError):
        raise PlaceSearchError(502, "天地图返回了无效的反编码结果，请重新取点") from None


def _parse_reverse_response(
    payload: dict[str, Any], request: ReverseGeocodingRequest, config: PlaceSearchConfig,
) -> PlaceSearchItem:
    if str(payload.get("status")) != "0":
        raise PlaceSearchError(502, "天地图反编码请求失败，请重新取点")
    result = payload.get("result")
    if not result:
        raise PlaceSearchError(404, "该位置未找到地名或地址，请重新取点")
    address = result.get("formatted_address")
    if not isinstance(address, str) or not address.strip():
        raise PlaceSearchError(404, "该位置未找到地名或地址，请重新取点")
    component = result.get("addressComponent") or {}
    validate_place_scope(
        config, county_code=str(component.get("county_code") or ""),
        county=str(component.get("county") or ""),
        province_code=str(component.get("province_code") or ""),
    )
    name = component.get("poi") or component.get("road") or address
    if not isinstance(name, str) or not name.strip():
        raise ValueError("Invalid place name")
    # A nearby POI can have a different center. Always retain the clicked point.
    return PlaceSearchItem(
        id=f"map:{request.longitude:.8f},{request.latitude:.8f}",
        name=name.strip(), address=address.strip(), longitude=request.longitude, latitude=request.latitude,
        category="附近地名" if component.get("poi") else "地址",
        district=str(component.get("county") or config.region),
    )