using SQLite;
using Phonebook.Models;
using System.Collections.ObjectModel;
using Contact = Phonebook.Models.Contact;
using System.Diagnostics;
using System.Globalization;

namespace Phonebook.Services
{
    public class DatabaseService
    {
        private SQLiteAsyncConnection _database;

        public DatabaseService()
        {
            Initialize();
        }

        private async void Initialize()
        {
            if (_database != null)
                return;

            _database = new SQLiteAsyncConnection(Path.Combine(FileSystem.AppDataDirectory, "contacts.db3"),
                SQLiteOpenFlags.Create | SQLiteOpenFlags.ReadWrite | SQLiteOpenFlags.SharedCache);

            await _database.CreateTableAsync<Contact>();
        }

        public async Task<List<Contact>> GetContactsAsync()
        {
            return await _database.Table<Contact>().ToListAsync();
        }

        public async Task<List<Contact>> SearchContactsAsync(string searchTerm)
        {
            if (string.IsNullOrWhiteSpace(searchTerm))
                return await GetContactsAsync();

            // Всегда получаем все контакты и фильтруем в памяти
            // Это обеспечит одинаковое поведение для всех языков
            var allContacts = await GetContactsAsync();
            var compareInfo = CultureInfo.CurrentCulture.CompareInfo;

            return allContacts?
                .Where(c =>
                    compareInfo.IndexOf(c.Name ?? "", searchTerm, CompareOptions.IgnoreCase) >= 0 ||
                    compareInfo.IndexOf(c.PhoneNumber ?? "", searchTerm, CompareOptions.IgnoreCase) >= 0 ||
                    compareInfo.IndexOf(c.Email ?? "", searchTerm, CompareOptions.IgnoreCase) >= 0 ||
                    compareInfo.IndexOf(c.Address ?? "", searchTerm, CompareOptions.IgnoreCase) >= 0 ||
                    compareInfo.IndexOf(c.Description ?? "", searchTerm, CompareOptions.IgnoreCase) >= 0)
                .DistinctBy(c => c.Id)
                .ToList() ?? new List<Contact>();
        }

        private bool ContainsCyrillic(string text)
        {
            return text.Any(c => c >= 'а' && c <= 'я' || c >= 'А' && c <= 'Я');
        }

        public async Task<Contact> GetContactAsync(int id)
        {
            return await _database.Table<Contact>().Where(c => c.Id == id).FirstOrDefaultAsync();
        }

        public async Task<Contact> SearchIdByNameOrDefault(Contact contact)
        {
            var dataList = await _database.Table<Contact>().Where(c => c.Name == contact.Name).ToListAsync();
            if(dataList.Count == 0) return contact;
            return dataList[0];
        }

        public async Task<int> SaveContactAsync(Contact contact)
        {
            if (contact.Id != 0)
            {
                return await _database.UpdateAsync(contact);
            }
            else
            {
                return await _database.InsertAsync(contact);
            }
        }

        public async Task SaveContactsAsync(List<Contact> contacts)
        {
            var insertList = new List<Contact>();
            var updateList = new List<Contact>();
            
            foreach (var contact in contacts)
            {
                if(contact.Id != 0)
                    updateList.Add(contact);
                else
                    insertList.Add(contact);
            }
            
            await _database.UpdateAllAsync(updateList);
            await _database.InsertAllAsync(insertList);
        }

        public async Task<int> DeleteContactAsync(Contact contact)
        {
            return await _database.DeleteAsync(contact);
        }

        public async Task ClearAll()
        {
            await _database.DeleteAllAsync<Contact>();
        }
    }
}