import httpx
import logging
import asyncio
import os
from typing import Optional
from schemas import NormalizedVitals
from config import settings

logger = logging.getLogger(__name__)

_http_client: Optional[httpx.AsyncClient] = None

def get_http_client() -> httpx.AsyncClient:
    global _http_client
    if _http_client is None or _http_client.is_closed:
        _http_client = httpx.AsyncClient(
            timeout=httpx.Timeout(connect=5.0, read=5.0, write=5.0, pool=10.0),
            limits=httpx.Limits(max_keepalive_connections=20, max_connections=50)
        )
    return _http_client

def get_cloud_base_url() -> str:
    url = getattr(settings, "cloud_api_url", None) or os.getenv("CLOUD_API_URL") or "https://services-api.a2zhealth.in/v1/contec-monitor"
    return url.rstrip("/")

async def forward_vitals_to_api(vitals: NormalizedVitals) -> bool:
    """
    Attempts to POST the normalized vitals to the configured target API
    and to the Cloud server concurrently.
    Returns True if at least one forward succeeds.
    """
    headers = {"Content-Type": "application/json"}
    
    # Strip heavy wave sample arrays before REST transmission (cloud APIs only ingest vital signs)
    payload = vitals.model_dump(mode="json")
    payload.pop("ecg_wave", None)
    payload.pop("pleth_wave", None)
    
    if not payload.get("patient_id"):
        payload["patient_id"] = "UNKNOWN"
        
    client = get_http_client()
    
    async def _post_target(url: str, label: str) -> bool:
        if not url:
            return False
        curr_port = os.getenv("PORT", "8000")
        if f":{curr_port}" in url and ("localhost" in url or "127.0.0.1" in url):
            return False
        try:
            req_headers = headers.copy()
            if settings.api_token:
                req_headers["Authorization"] = f"Bearer {settings.api_token}"
            url_to_call = url
            if settings.api_token and "?" not in url and "/api/push-vitals" in url:
                url_to_call = f"{url}?api_key={settings.api_token}"
            response = await client.post(url_to_call, json=payload, headers=req_headers)
            response.raise_for_status()
            logger.info(f"Successfully forwarded vitals to {label} ({url}) for device {vitals.device_id}")
            return True
        except Exception as e:
            err_msg = str(e).strip() or "timeout / connection reset"
            logger.warning(f"Error forwarding to {label} ({url}): {type(e).__name__} ({err_msg})")
            return False

    targets = []
    if settings.target_api_url:
        targets.append((settings.target_api_url, "Primary Target API"))

    cloud_base = get_cloud_base_url()
    is_on_cloud = os.getenv("RENDER") is not None or os.getenv("PORT") == "10000" or "render.local" in os.getenv("HOSTNAME", "")
    if not (is_on_cloud and "onrender.com" in cloud_base):
        cloud_push_url = f"{cloud_base}/api/push-vitals" if not cloud_base.endswith("/api/push-vitals") else cloud_base
        if cloud_push_url not in [t[0] for t in targets]:
            targets.append((cloud_push_url, "Cloud Server"))

    for extra_url in getattr(settings, "forward_urls", []):
        if extra_url and extra_url not in [t[0] for t in targets]:
            targets.append((extra_url, "Configured Forward URL"))

    tasks = [_post_target(url, lbl) for url, lbl in targets]
    results = await asyncio.gather(*tasks, return_exceptions=True)
    return any(r is True for r in results if not isinstance(r, Exception))


async def sync_patient_assignment_to_cloud(patient_data: dict, device_id: str) -> bool:
    """
    Synchronizes patient demographics assignment to Cloud and LAN servers.
    Ensures local and remote dashboards always show the exact same patient.
    """
    client = get_http_client()
    payload = {
        "device_id": device_id,
        "mrn": patient_data.get("mrn") or patient_data.get("patient_id") or "",
        "name": patient_data.get("name") or patient_data.get("patient_name") or "Unknown",
        "dob": patient_data.get("dob") or patient_data.get("patient_dob"),
        "gender": patient_data.get("gender") or patient_data.get("patient_gender"),
        "bed_id": patient_data.get("bed_id"),
        "patient_type": patient_data.get("patient_type")
    }

    targets = []
    cloud_base = get_cloud_base_url()
    targets.append(f"{cloud_base}/api/patient/assign")

    for extra_url in getattr(settings, "forward_urls", []):
        if "/api/push-vitals" in extra_url:
            assign_url = extra_url.replace("/api/push-vitals", "/api/patient/assign")
            if assign_url not in targets:
                targets.append(assign_url)

    async def _sync_one(url: str) -> bool:
        try:
            url_with_key = url
            if settings.api_token:
                url_with_key = f"{url}?api_key={settings.api_token}"
            resp = await client.post(url_with_key, json=payload, headers={"Content-Type": "application/json"})
            resp.raise_for_status()
            logger.info(f"Successfully synced patient {payload['mrn']} to {url} for {device_id}")
            return True
        except Exception as e:
            logger.warning(f"Could not sync patient assignment to {url}: {type(e).__name__} ({e})")
            return False

    results = await asyncio.gather(*[_sync_one(u) for u in targets], return_exceptions=True)
    return any(r is True for r in results if not isinstance(r, Exception))