using System.Net.Http.Json;
using System.Text;
using System.Text.Json;
using KronaStaffTerminal.Models;

namespace KronaStaffTerminal.Services;

public sealed class NotificationService
{
    private readonly HttpClient _httpClient = new() { Timeout = TimeSpan.FromSeconds(15) };

    public async Task<(bool Delivered, string? Error)> SendAttendanceAsync(TerminalSettings settings, EmployeeRecord employee, string eventType, DateTimeOffset localTime)
    {
        var action = eventType.StartsWith("Уход", StringComparison.Ordinal) ? "уход" : "приход";
        return await SendAsync(settings, employee,
            $"Krona Staff: ваш {action} зарегистрирован {localTime:dd.MM.yyyy} в {localTime:HH:mm}.");
    }

    public async Task<(bool Delivered, string? Error)> SendTestAsync(TerminalSettings settings, EmployeeRecord employee)
    {
        return await SendAsync(settings, employee, "Krona Staff: личные уведомления подключены.");
    }

    private async Task<(bool Delivered, string? Error)> SendAsync(TerminalSettings settings, EmployeeRecord employee, string text)
    {
        if (employee.IsBlocked) return (false, "Сотрудник заблокирован.");
        var errors = new List<string>();
        var sent = false;

        var telegramConfigured = settings.TelegramEnabled &&
                                 !string.IsNullOrWhiteSpace(settings.TelegramBotToken) &&
                                 !string.IsNullOrWhiteSpace(employee.TelegramChatId);
        if (telegramConfigured)
        {
            try
            {
                var url = $"https://api.telegram.org/bot{settings.TelegramBotToken}/sendMessage";
                using var response = await _httpClient.PostAsJsonAsync(url, new { chat_id = employee.TelegramChatId, text });
                if (!response.IsSuccessStatusCode)
                {
                    errors.Add($"Telegram: HTTP {(int)response.StatusCode}");
                }
                else
                {
                    sent = true;
                }
            }
            catch (Exception exception)
            {
                errors.Add($"Telegram: {exception.Message}");
            }
        }

        var vkConfigured = settings.VkEnabled &&
                           !string.IsNullOrWhiteSpace(settings.VkGroupToken) &&
                           !string.IsNullOrWhiteSpace(employee.VkPeerId);
        if (vkConfigured)
        {
            try
            {
                var values = new Dictionary<string, string>
                {
                    ["access_token"] = settings.VkGroupToken,
                    ["v"] = "5.199",
                    ["peer_id"] = employee.VkPeerId,
                    ["random_id"] = Random.Shared.Next(1, int.MaxValue).ToString(),
                    ["message"] = text
                };
                using var response = await _httpClient.PostAsync(
                    "https://api.vk.com/method/messages.send",
                    new FormUrlEncodedContent(values));
                var responseText = await response.Content.ReadAsStringAsync();
                if (!response.IsSuccessStatusCode || responseText.Contains("\"error\"", StringComparison.OrdinalIgnoreCase))
                {
                    errors.Add($"VK: HTTP {(int)response.StatusCode}");
                }
                else
                {
                    sent = true;
                }
            }
            catch (Exception exception)
            {
                errors.Add($"VK: {exception.Message}");
            }
        }

        var maxConfigured = settings.MaxEnabled &&
                            !string.IsNullOrWhiteSpace(settings.MaxBotToken) &&
                            !string.IsNullOrWhiteSpace(employee.MaxUserId);
        if (maxConfigured)
        {
            try
            {
                var url = $"https://platform-api2.max.ru/messages?user_id={Uri.EscapeDataString(employee.MaxUserId)}";
                using var request = new HttpRequestMessage(HttpMethod.Post, url);
                request.Headers.TryAddWithoutValidation("Authorization", settings.MaxBotToken);
                request.Content = new StringContent(JsonSerializer.Serialize(new { text }), Encoding.UTF8, "application/json");
                using var response = await _httpClient.SendAsync(request);
                if (!response.IsSuccessStatusCode)
                {
                    errors.Add($"MAX: HTTP {(int)response.StatusCode}");
                }
                else
                {
                    sent = true;
                }
            }
            catch (Exception exception)
            {
                errors.Add($"MAX: {exception.Message}");
            }
        }

        if (!telegramConfigured && !vkConfigured && !maxConfigured)
        {
            return (false, null);
        }

        return (sent && errors.Count == 0, errors.Count == 0 ? null : string.Join("; ", errors));
    }
}