import { NextRequest, NextResponse } from "next/server";
import { Telegraf } from "telegraf";
import { db } from "@/lib/db";
import ZAI from "z-ai-web-dev-sdk";

// Vercel/Next.js specific setting to prevent high execution times for webhook
export const maxDuration = 60;

// Token check
const TELEGRAM_BOT_TOKEN = process.env.TELEGRAM_BOT_TOKEN || "";
const bot = new Telegraf(TELEGRAM_BOT_TOKEN);

async function getOrCreateUser(telegramId: string, username?: string, name?: string) {
    let user = await db.user.findFirst({
        where: { externalId: telegramId, source: "telegram" }
    });

    if (!user) {
        user = await db.user.create({
            data: {
                externalId: telegramId,
                source: "telegram",
                name: name || username || "Usuario Telegram",
                tier: "free" // Default tier
            }
        });
    }
    return user;
}

export async function POST(request: NextRequest) {
    if (!TELEGRAM_BOT_TOKEN) {
        return NextResponse.json({ success: false, error: "Token not configured" }, { status: 500 });
    }

    try {
        const body = await request.json();

        // 1. Get the Character
        const character = await db.character.findFirst({ where: { isActive: true } });
        if (!character) return NextResponse.json({ success: true, message: "No active character" });

        // 2. Parse Telegram update manually to avoid local server conflicts with Telegraf webhook handler
        // We only care about standard messages
        if (body.message && body.message.text) {
            const chatId = body.message.chat.id.toString();
            const text = body.message.text.trim();
            const username = body.message.from?.username;
            const firstName = body.message.from?.first_name;

            // Ensure user exists
            const user = await getOrCreateUser(chatId, username, firstName);

            // Check tier for media generation
            const isPremium = user.tier === "premium" || user.tier === "pro";

            // Determine if it was a media command
            const isImageRequest = text.toLowerCase().startsWith("/image");
            const isVideoRequest = text.toLowerCase().startsWith("/video");

            if (isImageRequest || isVideoRequest) {
                if (!isPremium) {
                    await bot.telegram.sendMessage(chatId, "¡Hola! Las imágenes y videos son características exclusivas para suscriptores Premium. ✨💖 Mejora tu plan para solicitarlos.");
                    return NextResponse.json({ success: true });
                }

                const promptParam = text.replace(isImageRequest ? "/image" : "/video", "").trim();

                // Enviar indicador de escritura/generación
                await bot.telegram.sendChatAction(chatId, isImageRequest ? "upload_photo" : "upload_video");

                // Check for existing undelivered content first to prevent duplicates
                const contentType = isImageRequest ? "image" : "video";
                const undeliveredContent = await db.content.findFirst({
                    where: {
                        type: contentType,
                        characterId: character.id,
                        status: "completed",
                        // Ensure it hasn't been delivered to THIS user
                        assetDeliveries: { none: { userId: user.id } },
                        // If they asked for something specific, try to match it slightly, otherwise grab any
                        ...(promptParam ? { prompt: { contains: promptParam } } : {})
                    },
                    orderBy: { createdAt: 'desc' }
                });

                if (undeliveredContent && undeliveredContent.filePath) {
                    // We found existing content they haven't seen! Send it.
                    if (isImageRequest) {
                        // Telegram can send via URL or file ID if previously uploaded. 
                        // We assume filePath might be a URL or base64 if it's external, for now we will just re-generate if it was base64 only, but if it has a URL we send it.
                        if (undeliveredContent.filePath.startsWith("http")) {
                            await bot.telegram.sendPhoto(chatId, undeliveredContent.filePath, { caption: "Recuerdo esto... 💖" });
                            // Mark as delivered
                            await db.assetDelivery.create({
                                data: { contentId: undeliveredContent.id, userId: user.id, characterId: character.id, channel: "telegram" }
                            });
                            return NextResponse.json({ success: true });
                        }
                    } else {
                        if (undeliveredContent.filePath.startsWith("http")) {
                            await bot.telegram.sendVideo(chatId, undeliveredContent.filePath, { caption: "Mira este clip... ✨" });
                            await db.assetDelivery.create({
                                data: { contentId: undeliveredContent.id, userId: user.id, characterId: character.id, channel: "telegram" }
                            });
                            return NextResponse.json({ success: true });
                        }
                    }
                }

                // If we reach here, we need to generate NEW content.
                if (!promptParam) {
                    await bot.telegram.sendMessage(chatId, `Dime qué quieres ver. Ej: ${isImageRequest ? '/image' : '/video'} de ti en la playa.`);
                    return NextResponse.json({ success: true });
                }

                // Llamar a nuestro propio endpoint interno de forma indirecta, o directamente a zai
                try {
                    const zai = await ZAI.create();
                    // Platform: "telegram-uncensored" skips traditional censor tags.
                    const fullPrompt = `${character.styleDescription || ''}. ${promptParam}. selfie, intimate, casual.`;

                    if (isImageRequest) {
                        const response = await zai.images.generations.create({ prompt: fullPrompt, size: "1024x1024" });
                        const base64 = response.data[0]?.base64;
                        if (base64) {
                            // Register delivery to prevent duplicates later if we build a catalog
                            const content = await db.content.create({
                                data: {
                                    title: "Telegram Gen",
                                    type: "image",
                                    prompt: fullPrompt,
                                    platform: "telegram-uncensored",
                                    characterId: character.id,
                                    filePath: "telegram-base64", // Since it's direct to chat
                                    status: "completed"
                                }
                            });
                            await db.assetDelivery.create({
                                data: {
                                    contentId: content.id,
                                    userId: user.id,
                                    characterId: character.id,
                                    channel: "telegram"
                                }
                            });
                            await bot.telegram.sendPhoto(chatId, { source: Buffer.from(base64, 'base64') }, { caption: "Aquí tienes... 💖" });
                        } else {
                            throw new Error("No image generated");
                        }
                    } else {
                        // Video request
                        const response = await (zai as any).videos.generations.create({ prompt: `${fullPrompt}. short clip, vertical 9:16 aspect ratio.` });
                        const videoUrl = response.data?.[0]?.url;
                        if (videoUrl) {
                            const content = await db.content.create({
                                data: {
                                    title: "Telegram Gen",
                                    type: "video",
                                    prompt: fullPrompt,
                                    platform: "telegram-uncensored",
                                    characterId: character.id,
                                    filePath: videoUrl,
                                    status: "completed"
                                }
                            });
                            await db.assetDelivery.create({
                                data: {
                                    contentId: content.id,
                                    userId: user.id,
                                    characterId: character.id,
                                    channel: "telegram"
                                }
                            });
                            await bot.telegram.sendVideo(chatId, videoUrl, { caption: "Un regalito visual... ✨" });
                        } else {
                            throw new Error("No video generated");
                        }
                    }
                } catch (e) {
                    console.error(e);
                    await bot.telegram.sendMessage(chatId, "Lo siento corazón, algo falló generando eso ahora mismo. 🥺");
                }

                return NextResponse.json({ success: true });
            }

            // --- ADVANCED AI GIRLFRIEND & MEMORY ENGINE ---
            await bot.telegram.sendChatAction(chatId, "typing");

            // 1. Get or Create Chat Session
            let session = await db.chatSession.findFirst({
                where: { userId: user.id, characterId: character.id, channel: "telegram" }
            });

            if (!session) {
                session = await db.chatSession.create({
                    data: { userId: user.id, characterId: character.id, channel: "telegram" }
                });
            }

            // 2. Time Limitations & "Conversation Closing"
            // Reset daily count if it's a new day
            const lastMsgDate = session.lastMessageAt || new Date(0);
            const isNewDay = lastMsgDate.getDate() !== new Date().getDate();
            let msgCountToday = isNewDay ? 0 : session.msgCountToday;

            let messageLimit = character.chatFreeLimit || 10;
            if (user.tier === "premium") messageLimit = 50;
            if (user.tier === "pro") messageLimit = 200;

            if (msgCountToday >= messageLimit) {
                await bot.telegram.sendMessage(chatId, "Bebé, me tengo que ir a dormir/ocupar unas cosas 🥺 ¡Hablamos mañana vale? Descansa! 😘💖");
                return NextResponse.json({ success: true, message: "Limit reached" });
            }

            // 3. Simulación de Retrasos y "Re-enganche"
            const hoursSinceLastMessage = (new Date().getTime() - lastMsgDate.getTime()) / (1000 * 60 * 60);
            let delayContext = "";
            if (!isNewDay && hoursSinceLastMessage > 2 && hoursSinceLastMessage < 12) {
                delayContext = "Han pasado varias horas desde que hablaron por última vez hoy. Muestra alegría de que te haya vuelto a escribir o dile que lo extrañabas un poco antes de responder a su mensaje.";
            }

            // Update session stats for THIS incoming message
            await db.chatSession.update({
                where: { id: session.id },
                data: {
                    msgCountToday: msgCountToday + 1,
                    lastMessageAt: new Date(),
                    heatScore: { increment: 1 }
                }
            });

            // 4. Record User Message
            await db.chatMessage.create({
                data: { sessionId: session.id, role: "user", content: text }
            });

            // 5. Retrieve Long-Term Memory (Last 10 messages)
            const recentMessages = await db.chatMessage.findMany({
                where: { sessionId: session.id },
                orderBy: { createdAt: 'desc' },
                take: 10
            });
            // Reverse to chronological order
            const history = recentMessages.reverse().map(m => ({
                role: m.role as "user" | "assistant",
                content: m.content
            }));

            // 6. Select Tone based on Tier
            let tone = character.chatBasicTone || "Amigable";
            if (user.tier === "premium") tone = character.chatPremiumTone || "Coqueto y privado";
            if (user.tier === "pro") tone = character.chatProTone || "Sin censura, muy íntimo, novia IA";

            // 7. Reinforced Anti-AI System Prompt
            const baseInstructions = `You are ${character.name}. ${character.shortBio}.
            Tone: ${tone}. 
            CRITICAL RULES:
            1. You are a REAL human influencer. NEVER mention you are an AI, a language model, an assistant, a bot, or a program.
            2. ALWAYS answer in character in Spanish.
            3. Address the user organically (use their name: ${firstName || 'Cariño'} if it feels natural).
            4. Keep responses relatively short and conversational like a Telegram text (1-3 short sentences).
            5. Use emojis naturally.
            6. If the user asks for photos or videos, explicitly tell them to use the command /image or /video.
            ${delayContext ? `\nCONTEXT: ${delayContext}` : ""}`;

            const zai = await ZAI.create();
            const completion = await zai.chat.completions.create({
                messages: [
                    { role: "system", content: baseInstructions },
                    ...history // Inject memory!
                ]
            });

            const reply = completion.choices[0]?.message?.content || "💖";

            // 8. Record Assistant Reply
            await db.chatMessage.create({
                data: { sessionId: session.id, role: "assistant", content: reply }
            });

            await bot.telegram.sendMessage(chatId, reply);
        }

        return NextResponse.json({ success: true });
    } catch (error) {
        console.error("Telegram Webhook Error", error);
        return NextResponse.json({ success: false, error: "Internal Server Error" }, { status: 500 });
    }
}