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 Session (von Telegram aufgerufen – keine Cookie-Auth!)
        app.MapPost("/api/telegram/webhook/{sessionId}", HandleWebhook);

        // Session Telegram-Config speichern
        app.MapPut("/api/sessions/{sessionId}/telegram", HandleSaveTelegram);

        // Session Telegram-Config abrufen
        app.MapGet("/api/sessions/{sessionId}/telegram", HandleGetTelegram);

        // Webhook registrieren (pro Session)
        app.MapPost("/api/sessions/{sessionId}/telegram/register-webhook", HandleRegisterWebhook);

        // Webhook-Info (pro Session)
        app.MapGet("/api/sessions/{sessionId}/telegram/webhook-info", HandleWebhookInfo);

        // Webhook löschen (pro Session)
        app.MapDelete("/api/sessions/{sessionId}/telegram/webhook", HandleDeleteWebhook);
    }

    private static async Task HandleWebhook(string sessionId, HttpRequest req, HttpResponse res, TelegramService telegram, DatabaseService db)
    {
        var session = await db.GetSession(sessionId);
        if (session == null || string.IsNullOrEmpty(session.TelegramBotToken))
        {
            res.StatusCode = 404;
            return;
        }

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

        try
        {
            var body = await JsonSerializer.DeserializeAsync<JsonElement>(req.Body);
            // Fire-and-forget – Telegram erwartet schnelle 200 OK Antwort
            _ = Task.Run(async () =>
            {
                try { await telegram.HandleUpdate(body, session); }
                catch (Exception ex) { Console.Error.WriteLine($"[Telegram] Fehler für Session {sessionId}: {ex.Message}"); }
            });
        }
        catch
        {
            // Malformed JSON – ignorieren
        }

        res.StatusCode = 200;
    }

    private static async Task HandleSaveTelegram(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 botToken = body.TryGetProperty("botToken", out var t) ? t.GetString() : null;
        var webhookSecret = body.TryGetProperty("webhookSecret", out var s) ? s.GetString() : null;

        await db.UpdateSessionTelegram(sessionId, botToken, webhookSecret, session.TelegramChatId);
        await res.WriteAsJsonAsync(new { ok = true });
    }

    private static async Task HandleGetTelegram(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
        {
            botToken = session.TelegramBotToken ?? "",
            webhookSecret = session.TelegramWebhookSecret ?? "",
            chatId = session.TelegramChatId ?? "",
            configured = !string.IsNullOrEmpty(session.TelegramBotToken)
        });
    }

    private static async Task HandleRegisterWebhook(string sessionId, HttpRequest req, HttpResponse res, DatabaseService db, TelegramService telegram)
    {
        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);
        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(), sessionId);
        res.ContentType = "application/json";
        await res.WriteAsync(result);
    }

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

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

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

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