using System;
using System.Text.Json;
using System.Threading.Tasks;
using Gott.Extensions;
using Gott.Services;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;

namespace Gott.Endpoints;

public static class TelegramEndpoint
{
    public static void MapTelegramEndpoints(this IEndpointRouteBuilder app)
    {
        // Webhook pro Bot (von Telegram aufgerufen – keine Cookie-Auth!)
        app.MapPost("/api/telegram/webhook/{botId}", HandleWebhook);

        // ── Telegram Bot CRUD ──
        app.MapGet("/api/telegram/bots", HandleGetBots);
        app.MapGet("/api/telegram/bots/available", HandleGetAvailableBots);
        app.MapPost("/api/telegram/bots", HandleCreateBot);
        app.MapGet("/api/telegram/bots/{botId}", HandleGetBot);
        app.MapPut("/api/telegram/bots/{botId}", HandleUpdateBot);
        app.MapDelete("/api/telegram/bots/{botId}", HandleDeleteBot);

        // ── Webhook-Verwaltung (pro Bot) ──
        app.MapPost("/api/telegram/bots/{botId}/register-webhook", HandleRegisterWebhook);
        app.MapGet("/api/telegram/bots/{botId}/webhook-info", HandleWebhookInfo);
        app.MapDelete("/api/telegram/bots/{botId}/webhook", HandleDeleteWebhook);

        // ── Session Telegram-Config ──
        app.MapGet("/api/sessions/{sessionId}/telegram", HandleGetSessionTelegram);
        app.MapPut("/api/sessions/{sessionId}/telegram", HandleSaveSessionTelegram);
    }

    // ── Webhook Handler ──

    private static async Task HandleWebhook(string botId, HttpRequest req, HttpResponse res, TelegramService telegram, DatabaseService db)
    {
        var bot = await db.GetTelegramBot(botId);
        if (bot == null)
        {
            res.StatusCode = 404;
            return;
        }

        // Secret-Token prüfen
        var secret = req.Headers["X-Telegram-Bot-Api-Secret-Token"].ToString();
        if (!string.IsNullOrEmpty(bot.WebhookSecret) && secret != bot.WebhookSecret)
        {
            res.StatusCode = 403;
            return;
        }

        try
        {
            var body = await JsonSerializer.DeserializeAsync<JsonElement>(req.Body);
            _ = Task.Run(async () =>
            {
                try { await telegram.HandleUpdate(body, bot); }
                catch (Exception ex) { Console.Error.WriteLine($"[Telegram] Fehler für Bot {bot.Name}: {ex.Message}"); }
            });
        }
        catch
        {
            // Malformed JSON – ignorieren
        }

        res.StatusCode = 200;
    }

    // ── Bot CRUD ──

    private static async Task HandleGetBots(HttpRequest req, HttpResponse res, DatabaseService db)
    {
        var userId = req.HttpContext.GetUserId();
        var bots = await db.GetTelegramBots(userId);
        var result = new System.Collections.Generic.List<object>();
        foreach (var bot in bots)
        {
            var sessionCount = await db.GetTelegramBotSessionCount(bot.BotId);
            result.Add(new
            {
                botId = bot.BotId,
                name = bot.Name,
                botToken = bot.BotToken,
                webhookSecret = bot.WebhookSecret,
                isPublic = bot.IsPublic,
                sessionCount,
                createdAt = bot.CreatedAt,
                updatedAt = bot.UpdatedAt
            });
        }
        await res.WriteAsJsonAsync(result);
    }

    private static async Task HandleGetBot(string botId, HttpRequest req, HttpResponse res, DatabaseService db)
    {
        var userId = req.HttpContext.GetUserId();
        var bot = await db.GetTelegramBot(botId);
        if (bot == null || bot.UserId != userId)
        {
            res.StatusCode = 404;
            await res.WriteAsJsonAsync(new { error = "Bot nicht gefunden" });
            return;
        }

        var sessionCount = await db.GetTelegramBotSessionCount(bot.BotId);
        await res.WriteAsJsonAsync(new
        {
            botId = bot.BotId,
            name = bot.Name,
            botToken = bot.BotToken,
            webhookSecret = bot.WebhookSecret,
            isPublic = bot.IsPublic,
            sessionCount,
            createdAt = bot.CreatedAt,
            updatedAt = bot.UpdatedAt
        });
    }

    private static async Task HandleCreateBot(HttpRequest req, HttpResponse res, DatabaseService db)
    {
        var userId = req.HttpContext.GetUserId();
        var body = await JsonSerializer.DeserializeAsync<JsonElement>(req.Body);

        var name = body.TryGetProperty("name", out var n) ? n.GetString()?.Trim() : null;
        var botToken = body.TryGetProperty("botToken", out var t) ? t.GetString()?.Trim() : null;

        if (string.IsNullOrEmpty(name) || string.IsNullOrEmpty(botToken))
        {
            res.StatusCode = 400;
            await res.WriteAsJsonAsync(new { error = "Name und Bot-Token sind erforderlich" });
            return;
        }

        var bot = await db.CreateTelegramBot(userId, name, botToken);
        await res.WriteAsJsonAsync(new
        {
            botId = bot.BotId,
            name = bot.Name,
            botToken = bot.BotToken,
            webhookSecret = bot.WebhookSecret,
            createdAt = bot.CreatedAt
        });
    }

    private static async Task HandleUpdateBot(string botId, HttpRequest req, HttpResponse res, DatabaseService db)
    {
        var userId = req.HttpContext.GetUserId();
        var bot = await db.GetTelegramBot(botId);
        if (bot == null || bot.UserId != userId)
        {
            res.StatusCode = 404;
            await res.WriteAsJsonAsync(new { error = "Bot nicht gefunden" });
            return;
        }

        var body = await JsonSerializer.DeserializeAsync<JsonElement>(req.Body);
        var name = body.TryGetProperty("name", out var n) ? n.GetString()?.Trim() : bot.Name;
        var botToken = body.TryGetProperty("botToken", out var t) ? t.GetString()?.Trim() : bot.BotToken;
        var isPublic = body.TryGetProperty("isPublic", out var p) ? p.GetBoolean() : bot.IsPublic;

        await db.UpdateTelegramBot(botId, name, botToken, isPublic);
        await res.WriteAsJsonAsync(new { ok = true });
    }

    private static async Task HandleDeleteBot(string botId, HttpRequest req, HttpResponse res, DatabaseService db, TelegramService telegram)
    {
        var userId = req.HttpContext.GetUserId();
        var bot = await db.GetTelegramBot(botId);
        if (bot == null || bot.UserId != userId)
        {
            res.StatusCode = 404;
            await res.WriteAsJsonAsync(new { error = "Bot nicht gefunden" });
            return;
        }

        // Webhook bei Telegram löschen
        try { await telegram.DeleteWebhook(bot); } catch { /* ignore */ }

        await db.DeleteTelegramBot(botId);
        await res.WriteAsJsonAsync(new { ok = true });
    }

    // ── Webhook-Verwaltung ──

    private static async Task HandleRegisterWebhook(string botId, HttpRequest req, HttpResponse res, DatabaseService db, TelegramService telegram)
    {
        var userId = req.HttpContext.GetUserId();
        var bot = await db.GetTelegramBot(botId);
        if (bot == null || bot.UserId != userId)
        {
            res.StatusCode = 404;
            await res.WriteAsJsonAsync(new { error = "Bot nicht gefunden" });
            return;
        }

        var body = await JsonSerializer.DeserializeAsync<JsonElement>(req.Body);
        if (!body.TryGetProperty("baseUrl", out var urlEl))
        {
            res.StatusCode = 400;
            await res.WriteAsJsonAsync(new { error = "baseUrl required" });
            return;
        }

        var result = await telegram.RegisterWebhook(urlEl.GetString(), bot);
        res.ContentType = "application/json";
        await res.WriteAsync(result);
    }

    private static async Task HandleWebhookInfo(string botId, HttpRequest req, HttpResponse res, DatabaseService db, TelegramService telegram)
    {
        var userId = req.HttpContext.GetUserId();
        var bot = await db.GetTelegramBot(botId);
        if (bot == null || bot.UserId != userId)
        {
            res.StatusCode = 404;
            return;
        }

        var result = await telegram.GetWebhookInfo(bot);
        res.ContentType = "application/json";
        await res.WriteAsync(result);
    }

    private static async Task HandleDeleteWebhook(string botId, HttpRequest req, HttpResponse res, DatabaseService db, TelegramService telegram)
    {
        var userId = req.HttpContext.GetUserId();
        var bot = await db.GetTelegramBot(botId);
        if (bot == null || bot.UserId != userId)
        {
            res.StatusCode = 404;
            return;
        }

        var result = await telegram.DeleteWebhook(bot);
        res.ContentType = "application/json";
        await res.WriteAsync(result);
    }

    // ── Verfügbare Bots (eigene + public) ──

    private static async Task HandleGetAvailableBots(HttpRequest req, HttpResponse res, DatabaseService db)
    {
        var userId = req.HttpContext.GetUserId();
        var bots = await db.GetAvailableTelegramBots(userId);
        var result = new System.Collections.Generic.List<object>();
        foreach (var bot in bots)
        {
            var isOwner = bot.UserId == userId;
            result.Add(new
            {
                botId = bot.BotId,
                name = bot.Name,
                isOwner,
                isPublic = bot.IsPublic,
                createdAt = bot.CreatedAt,
                // Token nur für eigene Bots anzeigen
                botToken = isOwner ? bot.BotToken : null
            });
        }
        await res.WriteAsJsonAsync(result);
    }

    // ── Session Telegram-Config ──

    private static async Task HandleGetSessionTelegram(string sessionId, HttpRequest req, HttpResponse res, DatabaseService db)
    {
        var userId = req.HttpContext.GetUserId();
        var session = await db.GetSession(sessionId);
        if (session == null || session.UserId != userId)
        {
            res.StatusCode = 404;
            await res.WriteAsJsonAsync(new { error = "Session nicht gefunden" });
            return;
        }

        await res.WriteAsJsonAsync(new
        {
            telegramBotId = session.TelegramBotId ?? "",
            chatId = session.TelegramChatId ?? "",
            configured = !string.IsNullOrEmpty(session.TelegramBotId)
        });
    }

    private static async Task HandleSaveSessionTelegram(string sessionId, HttpRequest req, HttpResponse res, DatabaseService db)
    {
        var userId = req.HttpContext.GetUserId();
        var session = await db.GetSession(sessionId);
        if (session == null || session.UserId != userId)
        {
            res.StatusCode = 404;
            await res.WriteAsJsonAsync(new { error = "Session nicht gefunden" });
            return;
        }

        var body = await JsonSerializer.DeserializeAsync<JsonElement>(req.Body);
        var botId = body.TryGetProperty("telegramBotId", out var b) ? b.GetString() : null;
        var chatId = body.TryGetProperty("chatId", out var c) ? c.GetString() : session.TelegramChatId;

        // Bot-Zuordnung setzen
        if (botId != null)
        {
            await db.SetSessionTelegramBot(sessionId, string.IsNullOrEmpty(botId) ? null : botId);
        }

        // Chat-ID aktualisieren (leerer String → NULL)
        await db.UpdateSessionTelegramChat(sessionId, string.IsNullOrEmpty(chatId) ? null : chatId);

        await res.WriteAsJsonAsync(new { ok = true });
    }
}