import { useCallback, useEffect, useState } from "react";

const STORAGE_KEY = "wuyuanbiaoba_location_config";
const DEFAULT_LOCATION = {
   longitude: 0,
   latitude: 0,
};

const normalizeNumber = (value) => {
   const num = Number(value);
   return Number.isFinite(num) ? num : 0;
};

const normalizeLocation = (data) => ({
   longitude: normalizeNumber(data?.longitude),
   latitude: normalizeNumber(data?.latitude),
});

const readFromLocalStorage = () => {
   try {
      const raw = localStorage.getItem(STORAGE_KEY);
      return raw ? normalizeLocation(JSON.parse(raw)) : DEFAULT_LOCATION;
   } catch (error) {
      console.error("读取本地经纬度配置失败:", error);
      return DEFAULT_LOCATION;
   }
};

const saveToLocalStorage = (location) => {
   try {
      localStorage.setItem(STORAGE_KEY, JSON.stringify(location));
   } catch (error) {
      console.error("保存本地经纬度配置失败:", error);
   }
};

export const useLocationConfig = () => {
   const [location, setLocation] = useState(DEFAULT_LOCATION);
   const [loading, setLoading] = useState(true);
   const [storageMode, setStorageMode] = useState("device");

   const loadLocation = useCallback(async () => {
      setLoading(true);
      try {
         const response = await fetch("/location-config");
         if (!response.ok) {
            throw new Error(`HTTP ${response.status}`);
         }

         const data = normalizeLocation(await response.json());
         setLocation(data);
         saveToLocalStorage(data);
         setStorageMode("device");
         return data;
      } catch (error) {
         console.warn("设备端经纬度配置不可用，回退至浏览器存储:", error);
         const fallback = readFromLocalStorage();
         setLocation(fallback);
         setStorageMode("browser");
         return fallback;
      } finally {
         setLoading(false);
      }
   }, []);

   const saveLocation = useCallback(async (nextLocation) => {
      const normalized = normalizeLocation(nextLocation);

      try {
         const response = await fetch("/location-config", {
            method: "POST",
            headers: {
               "Content-Type": "application/json",
            },
            body: JSON.stringify(normalized),
         });

         if (!response.ok) {
            throw new Error(`HTTP ${response.status}`);
         }

         const saved = normalizeLocation(await response.json());
         setLocation(saved);
         saveToLocalStorage(saved);
         setStorageMode("device");
         return { success: true, data: saved, storageMode: "device" };
      } catch (error) {
         console.warn("设备端保存失败，改为浏览器本地保存:", error);
         saveToLocalStorage(normalized);
         setLocation(normalized);
         setStorageMode("browser");
         return { success: true, data: normalized, storageMode: "browser" };
      }
   }, []);

   useEffect(() => {
      loadLocation();
   }, [loadLocation]);

   return {
      location,
      loading,
      storageMode,
      loadLocation,
      saveLocation,
   };
};

export default useLocationConfig;