import { useState, useCallback } from "react";
import { Platform, Alert } from "react-native";
import type { WallpaperConfig } from "@/types/wallpaper";

type ExportStatus = "idle" | "preparing" | "exporting" | "success" | "error";

interface ExportResult {
  status: ExportStatus;
  progress: number;
  error: string | null;
  exportAsWallpaper: (config: WallpaperConfig) => Promise<void>;
}

export function useWallpaperExport(): ExportResult {
  const [status, setStatus] = useState<ExportStatus>("idle");
  const [progress, setProgress] = useState(0);
  const [error, setError] = useState<string | null>(null);

  const exportAsWallpaper = useCallback(async (config: WallpaperConfig) => {
    try {
      setStatus("preparing");
      setProgress(0);
      setError(null);

      if (Platform.OS === "android") {
        await exportAndroid(config, setProgress, setStatus);
      } else if (Platform.OS === "ios") {
        await exportIOS(config, setProgress, setStatus);
      } else {
        throw new Error("Platform non supportée. Utilisez Android ou iOS.");
      }

      setStatus("success");
      setProgress(1);
    } catch (err) {
      const message = err instanceof Error ? err.message : "Échec de l'export";
      setError(message);
      setStatus("error");
      Alert.alert("Erreur d'export", message);
    }
  }, []);

  return { status, progress, error, exportAsWallpaper };
}

async function exportAndroid(
  config: WallpaperConfig,
  onProgress: (p: number) => void,
  onStatus: (s: ExportStatus) => void
) {
  // Lazy-load native module (only available on Android device builds)
  let WallpaperAndroid: typeof import("../../modules/wallpaper-android/src/WallpaperAndroidModule").WallpaperAndroid;
  try {
    WallpaperAndroid =
      require("../../modules/wallpaper-android/src/WallpaperAndroidModule").WallpaperAndroid;
  } catch {
    Alert.alert(
      "Module non disponible",
      "Le module natif Android n'est pas disponible dans Expo Go. Créez un development build avec `npx expo run:android`.",
    );
    return;
  }

  // Check support
  const supported = WallpaperAndroid.isLiveWallpaperSupported();
  if (!supported) {
    throw new Error("Les live wallpapers ne sont pas supportés sur cet appareil.");
  }

  onProgress(0.2);
  onStatus("exporting");

  // Save config to SharedPreferences (read by LiveWallpaperService)
  const configJson = JSON.stringify({
    sourceUri: config.sourceUri,
    depthMapUri: config.depthMapUri ?? "",
    animation: config.animation,
    uniforms: config.uniforms,
    fps: config.fps,
  });

  await WallpaperAndroid.saveConfig(configJson);
  onProgress(0.6);

  // Launch system wallpaper picker
  await WallpaperAndroid.setLiveWallpaper();
  onProgress(1.0);
}

async function exportIOS(
  config: WallpaperConfig,
  onProgress: (p: number) => void,
  onStatus: (s: ExportStatus) => void
) {
  let LivePhoto: typeof import("../../modules/livephoto-ios/src/LivePhotoModule").LivePhoto;
  try {
    LivePhoto =
      require("../../modules/livephoto-ios/src/LivePhotoModule").LivePhoto;
  } catch {
    Alert.alert(
      "Module non disponible",
      "Le module natif iOS n'est pas disponible dans Expo Go. Créez un development build avec `npx expo run:ios`.",
    );
    return;
  }

  // Check/request photo library permission
  let permission = await LivePhoto.checkPermission();
  if (permission === "undetermined") {
    permission = await LivePhoto.requestPermission();
  }
  if (permission !== "granted") {
    throw new Error(
      "Accès à la photothèque refusé. Activez-le dans Réglages > Lively > Photos."
    );
  }

  onProgress(0.1);
  onStatus("exporting");

  const configJson = JSON.stringify({
    sourceUri: config.sourceUri,
    depthMapUri: config.depthMapUri ?? "",
    animation: config.animation,
    uniforms: config.uniforms,
    fps: config.fps,
  });

  onProgress(0.3);

  // Generate Live Photo (HEIC + MOV) and save to photo library
  await LivePhoto.exportLivePhoto(configJson);

  onProgress(0.9);

  // Guide user to apply the wallpaper
  Alert.alert(
    "Live Photo sauvegardée",
    "Pour l'appliquer comme fond d'écran :\n\n" +
      "Réglages > Fond d'écran > Ajouter\n" +
      "> Photos > Sélectionnez votre Live Photo\n" +
      "> Activez « Live Photo »",
    [{ text: "OK" }]
  );

  onProgress(1.0);
}