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();
  }

  // FaceBook登录
  // 修改后的 signInWithFacebook
  Future<bool> signInWithFacebook() async {
    try {
      final rawNonce = generateNonce();
      final nonce = sha256ofString(rawNonce);
      final LoginResult loginResult = await FacebookAuth.instance
          .login(
        loginTracking: LoginTracking.enabled,
        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 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();
  }
}