import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import '../constants.dart';
import '../enumerations.dart';
import '../models/language.dart';
import '../models/location.dart';
import '../models/user_profile.dart';

class UserService {
  UserService._(); // Private constructor to prevent instantiation

  static Future<void> saveUserData(UserCredential userCredential, String email,
      String firstname, String lastname) async {
    // create full name
    String fullName = (firstname.isNotEmpty && lastname.isNotEmpty)
        ? '$firstname $lastname'
        : (firstname.isNotEmpty
            ? firstname
            : (lastname.isNotEmpty ? lastname : ''));

    // save user info to users document
    await FirebaseFirestore.instance
        .collection(Constants.dbCollectionUsers)
        .doc(userCredential.user!.uid)
        .set(
      {
        Constants.dbFieldUsersID: userCredential.user!.uid,
        Constants.dbFieldUsersEmail: email,
        Constants.dbFieldUsersFirstName: firstname,
        Constants.dbFieldUsersLastName: lastname,
        Constants.dbFieldUsersName: fullName,
      },
    );
  }

  static Future<List<SkillOption>> getSkillsFromFirebase(
      bool skillsSought, String userId) async {
    // Fetch skills from Firestore
    DocumentSnapshot userDoc = await FirebaseFirestore.instance
        .collection(Constants.dbCollectionUsers)
        .doc(userId)
        .get();

    if (userDoc.exists && userDoc.data() != null) {
      Map<String, dynamic> userData =
          userDoc.data()! as Map<String, dynamic>; // Explicit cast

      List<dynamic>? skills;
      if (skillsSought) {
        skills = userData[Constants.dbFieldUsersSkillsSought];
      } else {
        skills = userData[
            Constants.dbFieldUsersSkills]; //as List<dynamic>?; // Explicit cast
      }

      if (skills != null && skills.isNotEmpty) {
        // Convert skills from strings to enum values
        List<SkillOption> userSkills = skills
            .map((skill) => SkillOption.values
                .firstWhere((x) => x.toString() == 'SkillOption.$skill'))
            .toList();
        return userSkills;
      }
    }

    return [];
  }

  static Future<bool> saveSkillsToFirebase(List<SkillOption> selectedOptions,
      bool skillsSought, String userId) async {
    try {
      // Convert enum values to strings, removing leading EnumType with split
      List<String> skills = selectedOptions
          .map((option) => option.toString().split('.').last)
          .toList();

      // Update the corresponding 'skills' field in the user's document
      String keyToUpdate = skillsSought
          ? Constants.dbFieldUsersSkillsSought
          : Constants.dbFieldUsersSkills;

      FirebaseFirestore.instance
          .collection(Constants.dbCollectionUsers)
          .doc(userId)
          .update({keyToUpdate: skills});

      return true;
    } catch (e) {
      return false;
    }
  }

  /// Get UserProfile for given [userId]
  static Future<UserProfile> getUserProfileById(String userId) async {
    DocumentSnapshot doc = await FirebaseFirestore.instance
        .collection(Constants.dbCollectionUsers)
        .doc(userId)
        .get();
    return UserProfile.fromDocument(doc);
  }

  static Future<UserProfile> getDataById(String userId) async {
    FirebaseFirestore firestore = FirebaseFirestore.instance;

    DocumentSnapshot userDoc = await firestore
        .collection(Constants.dbCollectionUsers)
        .doc(userId)
        .get();

    QuerySnapshot languagesSnapshot = await firestore
        .collection(Constants.dbCollectionUsers)
        .doc(userId)
        .collection(Constants.dbCollectionLanguages)
        .get();
    List<Language> languages = languagesSnapshot.docs
        .map((doc) => Language.fromDocument(doc))
        .toList();

    QuerySnapshot locationsSnapshot = await firestore
        .collection(Constants.dbCollectionUsers)
        .doc(userId)
        .collection(Constants.dbCollectionLocations)
        .get();
    Map<String, MyLocation?> locations = {
      for (var doc in locationsSnapshot.docs)
        doc.id: MyLocation.fromDocument(doc)
    };

    // Fill UserProfile including its sub collections
    UserProfile userProfile = UserProfile.fromDocument(userDoc);
    userProfile.languages.addAll(languages);
    userProfile.locations.addAll(locations);

    return userProfile;
  }
}