#nullable enable

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using BotFramework.Abstractions;
using Kruzya.TelegramBot.Core.Cache;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using Telegram.Bot;
using Telegram.Bot.Types;

namespace Kruzya.TelegramBot.Core.Service;

public class UserService
{
    private readonly IEnumerable<long> _superUsers;
    private readonly IEnumerable<long> _badLuckUsers;
    private readonly Dictionary<long, string?> _statusMap;
    private readonly ICacheStorage<long, User> _userCache;
    private readonly ITelegramBotClient _bot;
    private readonly ILogger<UserService> _logger;


    public UserService(
        IConfiguration configuration, 
        IBotInstance bot, 
        ICacheStorage<long, User> userCache,
        ILogger<UserService> logger)
    {
        _superUsers = configuration.GetSection("SuperUsers").Get<List<long>>() ?? new List<long>();
        _badLuckUsers = configuration.GetSection("BadLuckUsers").Get<List<long>>() ?? new List<long>();

        _statusMap = configuration.GetSection("CustomMemberStatus")
            .GetChildren()
            .ToDictionary(x => Convert.ToInt64(x.Key), x => x.Value);
        
        _userCache = userCache;
        _bot = bot.BotClient;
        _logger = logger;
    }

    public async Task<User> GetUser(long userId, long chatId, bool bypassCache = false)
    {
        if (bypassCache || !_userCache.TryGetValue(userId, out var user))
        {
            if (bypassCache)
            {
                _logger.LogDebug("Bypassing cache for {UserId}.", userId);
            }
            else
            {
                _logger.LogDebug("User {UserId} is not found in cache. Fetching from Telegram API.", userId);
            }

            user = await GetUserByChat(chatId, userId);
            CacheUser(user);
        }
         
        return user;
    }

    private void CacheUser(User user)
    {
        // TODO: config entry for TTL
        _userCache.SetValue(user.Id, user, Convert.ToInt32(TimeSpan.FromHours(1).TotalSeconds));
    }
        
    private async Task<User> GetUserByChat(long chatId, long userId)
    {
        return (await _bot.GetChatMember(chatId, userId)).User;
    }

    public bool IsUserSuper(User user)
    {
        return IsUserSuper(user.Id);
    }
        
    public bool IsUserSuper(long userId)
    {
        return _superUsers.Contains(userId);
    }

    public bool IsUserUnlucky(long userId) 
    {
        return _badLuckUsers.Contains(userId);
    }

    public string? GetUserCustomStatus(long userId)
    {
        return _statusMap.ContainsKey(userId) ? _statusMap[userId] : null;
    }
}