import logging
import random
import time

import httpx

from app.config import settings
from app.utils.redis import get_redis

logger = logging.getLogger("videogen")

# In-memory fallback for verification codes
_sms_code_store: dict[str, tuple[str, float]] = {}


def _generate_code(length: int = 6) -> str:
    return "".join(random.choices("0123456789", k=length))


async def send_sms(phone: str, code: str) -> bool:
    """Send SMS verification code. Supports mock mode and real HTTP gateway."""
    if settings.SMS_MOCK or not settings.SMS_API_URL:
        logger.info(f"[SMS MOCK] To={phone}, Code={code}")
        return True

    try:
        payload = {
            "phone": phone,
            "code": code,
            "sign_name": settings.SMS_SIGN_NAME,
            "template_code": settings.SMS_TEMPLATE_CODE,
        }
        headers = {
            "Authorization": f"Bearer {settings.SMS_API_KEY}",
            "Content-Type": "application/json",
        }
        async with httpx.AsyncClient(timeout=10) as client:
            resp = await client.post(settings.SMS_API_URL, json=payload, headers=headers)
            resp.raise_for_status()
            return True
    except Exception:
        logger.exception(f"SMS send failed for {phone}")
        return False


async def store_sms_code(phone: str, code: str, ttl: int = 300) -> None:
    """Store SMS verification code with TTL (default 5 minutes)."""
    redis = get_redis()
    if redis:
        await redis.setex(f"sms_code:{phone}", ttl, code)
    else:
        _sms_code_store[phone] = (code, time.time() + ttl)


async def generate_and_send_sms(phone: str) -> bool:
    """Generate a code, store it, and send it via SMS."""
    code = _generate_code()
    ok = await send_sms(phone, code)
    if ok:
        await store_sms_code(phone, code)
    return ok


async def verify_sms_code(phone: str, code: str) -> bool:
    """Verify an SMS verification code."""
    redis = get_redis()
    if redis:
        stored = await redis.get(f"sms_code:{phone}")
        if stored and stored == code:
            await redis.delete(f"sms_code:{phone}")
            return True
        return False
    else:
        entry = _sms_code_store.pop(phone, None)
        if entry:
            stored_code, expires = entry
            if time.time() < expires and stored_code == code:
                return True
        return False