import 'dart:convert';
import 'dart:io';
import 'dart:math';

import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_facebook_auth/flutter_facebook_auth.dart';
import 'package:get/get.dart';
import 'package:crypto/crypto.dart';

class Facebook {
  String? token = '';

  String name = '';
  String email = '';
  String pictureurl = '';
  String id = '';
  String generateNonce([int length = 32]) {
    const charset =
        '0123456789ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz-._';
    final random = Random.secure();
    return List.generate(length, (_) => charset[random.nextInt(charset.length)])
        .join();
  }

  /// Returns the sha256 hash of [input] in hex notation.
  String sha256ofString(String input) {
    final bytes = utf8.encode(input);
    final digest = sha256.convert(bytes);
    return digest.toString();
  }

  Future<bool> signInWithFacebook() async {
    try {
      UserCredential userCredential = await loginFacebook();
      //UserCredential userCredential = await loginGoogle();
      token = await userCredential.user?.getIdToken();
      print('facebook响应数据userCredential: $token');
      if (token != "") {
        return true;
      } else {
        return false;
      }
    } catch (e) {
      print(e);
      return false;
    }
  }

  // FaceBook登录
  // 修改后的 signInWithFacebook
  Future<UserCredential> loginFacebook() async {
    //try {
    final rawNonce = generateNonce();
    final nonce = sha256ofString(rawNonce);
    final LoginResult loginResult = await FacebookAuth.instance
        .login(
      loginTracking: LoginTracking.limited, // 改为limited，禁用用户跟踪
      nonce: nonce,
    )
        .catchError((onError) {
      if (kDebugMode) {
        //print(onError);
      }
      throw Exception(onError.message);
    });
    if (loginResult.accessToken == null) {
      throw Exception(loginResult.message);
    }
    // Create a credential from the access token
    OAuthCredential facebookAuthCredential;

    print("tokenType${loginResult.accessToken!.type}");

    if (Platform.isIOS) {
      // Create a credential from the access token
      switch (loginResult.accessToken!.type) {
        case AccessTokenType.classic:
          final classicToken = loginResult.accessToken as ClassicToken;
          // token = classicToken.tokenString;
          print('Token 字符串: ${classicToken.tokenString}');
          print('classicToken值: ${classicToken}');
          facebookAuthCredential = FacebookAuthProvider.credential(
            classicToken.authenticationToken!,
          );
          break;
        case AccessTokenType.limited:
          final limitedToken = loginResult.accessToken as LimitedToken;
          //token = limitedToken.tokenString;
          print('Token 字符串: ${limitedToken.tokenString}');
          print('LimitedToken值: ${limitedToken}');
          facebookAuthCredential = OAuthCredential(
            providerId: 'facebook.com',
            signInMethod: 'oauth',
            idToken: limitedToken.tokenString,
            rawNonce: rawNonce,
          );
          break;
      }
    } else {
      facebookAuthCredential = FacebookAuthProvider.credential(
        loginResult.accessToken!.tokenString,
      );
      //token = loginResult.accessToken!.tokenString;
    }
    print('facebookAuthCredential值: ${facebookAuthCredential}');
    if (facebookAuthCredential == null) {
      throw Exception("Facebook Login Fail.");
    }
    final userData = await FacebookAuth.instance.getUserData();
    name = userData["name"].toString();

    email = userData["email"].toString();
    pictureurl = userData["picture"]["data"]["url"].toString();
    id = userData["id"].toString();
    print("user login facebook ${email}${pictureurl}${name}${id}");
    return FirebaseAuth.instance.signInWithCredential(facebookAuthCredential);

    //  final User? user = userCredential.user; // 获取用户信息
    //   token = await userCredential.user?.getIdToken();
    //   print("irebaseAuth.instance.signInWithCredential ${token}");

    //   return true;
    // } catch (e) {
    //   print("Facebook 登录异常：$e");
    //   return false;
    // }
  }

  // 退出Google登录
  Future<void> signOutFacebook() async {
    await FacebookAuth.instance.logOut();
  }
}