import asyncio
import json
import logging
import uuid
from datetime import datetime, timezone

import httpx

from .endpoint_security import payload_signature
from .models import SmsDeliveryWebhook

logger = logging.getLogger(__name__)


def _event_body(data: dict) -> bytes:
    payload = {
        "id": f"evt_{uuid.uuid4().hex}",
        "event": "message.delivery.updated",
        "created_at": datetime.now(timezone.utc).isoformat(),
        "data": data,
    }
    return json.dumps(payload, separators=(",", ":"), ensure_ascii=False).encode()


async def deliver_report(
    endpoint: SmsDeliveryWebhook,
    data: dict,
    *,
    attempts: int = 3,
) -> int:
    body = _event_body(data)
    headers = {
        "Content-Type": "application/json",
        "User-Agent": "Urmi-Webhooks/1.0",
        "X-Urmi-Event": "message.delivery.updated",
        "X-Urmi-Endpoint-Id": str(endpoint.id),
        "X-Urmi-Signature": payload_signature("webhook", endpoint.id, body),
    }
    last_error: Exception | None = None
    async with httpx.AsyncClient(timeout=10.0, follow_redirects=False) as client:
        for attempt in range(attempts):
            try:
                response = await client.post(endpoint.url, content=body, headers=headers)
                response.raise_for_status()
                return response.status_code
            except (httpx.HTTPError, httpx.TimeoutException) as exc:
                last_error = exc
                if attempt + 1 < attempts:
                    await asyncio.sleep(2**attempt)
    logger.warning("SMS delivery webhook failed endpoint=%s: %s", endpoint.id, last_error)
    raise RuntimeError("Webhook endpoint did not return a successful response") from last_error


async def deliver_test_report(endpoint: SmsDeliveryWebhook) -> int:
    if not endpoint.enabled:
        raise RuntimeError("Webhook is disabled")
    return await deliver_report(
        endpoint,
        {
            "message_id": f"msg_test_{uuid.uuid4().hex[:16]}",
            "to": "+919999999999",
            "from": endpoint.phone_number.phone_number if endpoint.phone_number else "test",
            "status": "delivered",
            "updated_at": datetime.now(timezone.utc).isoformat(),
            "test": True,
        },
        attempts=1,
    )