# app/routes/wa_gateway.py
from fastapi import APIRouter, Request
import os, requests, asyncio
from dotenv import load_dotenv
from fastapi.responses import PlainTextResponse, JSONResponse

# ----- import the Q&A logic -----
from routes.question import ask_question, QuestionInput   # ← new

load_dotenv()

wa_router = APIRouter()

VERIFY_TOKEN      = os.getenv("VERIFY_TOKEN")
ACCESS_TOKEN      = os.getenv("WHATSAPP_ACCESS_TOKEN")
PHONE_NUMBER_ID   = os.getenv("WHATSAPP_PHONE_NUMBER_ID")

def send_whatsapp_text(to: str, text: str) -> dict:
    """
    Send a plain text message (max 4096 chars per WhatsApp limits).
    Returns {'status': 'sent' | 'failed', ... } for easy logging.
    """
    url = f"https://graph.facebook.com/v17.0/{PHONE_NUMBER_ID}/messages"
    headers = {
        "Authorization": f"Bearer {ACCESS_TOKEN}",
        "Content-Type":  "application/json",
    }
    payload = {
        "messaging_product": "whatsapp",
        "to":   to,
        "type": "text",
        "text": {"body": text[:4096]},
    }

    try:
        r = requests.post(url, headers=headers, json=payload)
        r.raise_for_status()
        return {"status": "sent", "response": r.json()}
    except Exception as e:
        return {"status": "failed", "error": str(e)}

async def nuse_interact(to: str, name: str, prompt: str) -> dict:
    """
    1. Call ask_question() directly (no HTTP round-trip);
    2. Extract the answer text (+sources or headlines);
    3. Push it back to the user via WhatsApp API using link previews.
    """
    qa_result = await ask_question(QuestionInput(question=prompt))
    answer_text = qa_result["answer"]

    # If headlines were returned (qid == 13)
    if "headlines" in qa_result:
        headlines = qa_result["headlines"]
        if not headlines:
            return send_whatsapp_text(to, "Sorry, no headlines found today.")

        # Build preview message
        preview_msgs = []
        for h in headlines:
            preview_msgs.append(
                f"🗞️ *{h['title']}* ({h.get('category', '').title()})\n{h['summary']}\n🔗 {h['url']}"
            )

        message = f"{answer_text}\n\n" + "\n\n".join(preview_msgs[:10])  # show up to 10
        return send_whatsapp_text(to, message)

    # Fallback: regular Q&A with optional sources
    if qa_result.get("sources"):
        bullet_list = "\n".join(f"• {s['title']} – {s['url']}" for s in qa_result["sources"])
        answer_text = f"{answer_text}\n\nSources:\n{bullet_list}"

    return send_whatsapp_text(to, answer_text)

@wa_router.get("/webhook")
async def verify_webhook(request: Request):
    params = request.query_params
    if params.get("hub.mode") == "subscribe" and params.get("hub.verify_token") == VERIFY_TOKEN:
        return PlainTextResponse(content=params.get("hub.challenge"))
    return JSONResponse(status_code=403, content={"error": "Verification failed"})

@wa_router.post("/webhook")
async def receive_whatsapp_event(request: Request):
    body = await request.json()
    print("[WEBHOOK] Incoming:", body)

    try:
        entry    = body["entry"][0]
        changes  = entry["changes"][0]
        value    = changes["value"]
        messages = value.get("messages")
        contacts = value.get("contacts")

        if messages and contacts:
            msg     = messages[0]
            contact = contacts[0]

            from_number  = msg["from"]
            sender_name  = contact["profile"]["name"]
            incoming_txt = msg["text"]["body"]

            print(f"[INFO] {sender_name} ({from_number}): {incoming_txt}")

            # Hand off to Q&A -> WhatsApp reply
            result = await nuse_interact(from_number, sender_name, incoming_txt)
            print("[INFO] Reply status:", result)

    except Exception as e:
        print("[ERROR] Webhook processing failed:", str(e))

    return JSONResponse(content={"status": "received"})