from datetime import datetime
import requests
import urllib3
import os
import json
from typing import Optional, Dict, Any
from dotenv import load_dotenv

from logger_manager import get_logger

logger = get_logger()
# ============================================================================

urllib3.disable_warnings()

load_dotenv(dotenv_path=".env")

SAPB1_URL = os.getenv("SAP_B1_URL", "")
SAPB1_TIMEOUT = float(os.getenv("SAP_B1_TIMEOUT", 15.0))
SAPB1_VERIFY_SSL = os.getenv("SAP_B1_VERIFY_SSL", "False").lower() == "true"

# Almacenamiento global de sesión
_sap_session: dict = {"headers": None, "b1session": None, "routeid": None}
_sap_credentials: dict = {}


# ============================================================================
# LOGIN
# ============================================================================
def login() -> dict:
    if not _sap_credentials:
        raise RuntimeError("No hay credenciales. Asigna sapb1_manager._sap_credentials antes de llamar login().")
    payload = {
        "CompanyDB": _sap_credentials["company"],
        "UserName": _sap_credentials["username"],
        "Password": _sap_credentials["password"],
    }
    logger.info("🔐 Iniciando sesión en SAP B1 Service Layer...")
    resp = requests.post(
        f"{SAPB1_URL}/Login",
        json=payload,
        timeout=SAPB1_TIMEOUT,
        verify=SAPB1_VERIFY_SSL,
    )
    if resp.status_code != 200:
        raise ConnectionError(
            f"Login fallido: HTTP {resp.status_code} - {resp.text}"
        )

    data = resp.json()
    b1session = data["SessionId"]
    routeid = resp.cookies.get("ROUTEID", "")

    headers = {"Cookie": f"B1SESSION={b1session}; ROUTEID={routeid}"}
    _sap_session.update({"headers": headers, "b1session": b1session, "routeid": routeid})
    logger.info(f"✅ Sesión SAP B1 establecida  (B1SESSION: {b1session[:10]}...)")
    return headers


# ============================================================================
# LOGOUT
# ============================================================================
def logout():
    if not _sap_session["b1session"]:
        logger.warning("⚠️ No hay sesión activa para cerrar.")
        return
    logger.info("🔓 Cerrando sesión SAP B1...")
    try:
        resp = requests.post(
            f"{SAPB1_URL}/Logout",
            headers=_sap_session["headers"],
            timeout=SAPB1_TIMEOUT,
            verify=SAPB1_VERIFY_SSL,
        )
        if resp.status_code == 200:
            logger.info("✅ Sesión SAP B1 cerrada correctamente.")
        else:
            logger.warning(f"⚠️ Logout respondió HTTP {resp.status_code}")
    except Exception as exc:
        logger.error(f"❌ Error al cerrar sesión: {exc}")
    finally:
        _sap_session.update({"headers": None, "b1session": None, "routeid": None})
        _sap_credentials.clear()


# ============================================================================
# SESIÓN (interna - lazy login)
# ============================================================================
def _ensure_session() -> dict:
    if _sap_session["headers"]:
        return _sap_session["headers"]
    if _sap_credentials:
        return login()
    raise RuntimeError("No hay sesión ni credenciales para autenticarse en SAP B1.")


# ============================================================================
# LOGGING DE RESPUESTA
# ============================================================================
def _log_response(method: str, endpoint: str, response: requests.Response, payload: Any = None):
    log_line = (
        f"   │ [{method}] {endpoint} → {response.status_code}"
        f" ({len(response.content)} bytes)"
    )
    if response.status_code >= 400:
        logger.warning(f"   │ ⚠️ {log_line} - {response.text[:300]}")
    else:
        logger.info(log_line)


# ============================================================================
# PROXY CENTRALIZADO
# ============================================================================
def forward_to_sapb1(
    method: str,
    endpoint_path: str,
    json_data: Optional[Dict[str, Any]] = None,
    params: Optional[Dict[str, Any]] = None,
) -> requests.Response:
    if not method or not endpoint_path:
        raise ValueError("   │ method y endpoint_path son requeridos")

    method = method.upper()
    headers = _ensure_session()

    url = f"{SAPB1_URL}/{endpoint_path}"
    req_headers = {
        "Content-Type": "application/json",
        "Accept": "application/json",
        **_sap_session["headers"],
    }

    logger.info(f"   │ 🔄 [{method}] {endpoint_path} | {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}")

    try:
        resp = requests.request(
            method=method,
            url=url,
            json=json_data,
            params=params,
            headers=req_headers,
            timeout=SAPB1_TIMEOUT,
            verify=SAPB1_VERIFY_SSL,
        )
    except requests.exceptions.Timeout:
        raise ConnectionError(f"   │ Timeout ({SAPB1_TIMEOUT}s) en {endpoint_path}")
    except requests.exceptions.ConnectionError as exc:
        raise ConnectionError(f"   │ No se pudo conectar con SAP B1: {exc}")
    except requests.RequestException as exc:
        raise ConnectionError(f"   │ Error en solicitud HTTP: {exc}")

    if resp.status_code == 401:
        if not _sap_credentials:
            raise ConnectionError("Sesión expirada (401) y no hay credenciales para re-autenticar.")
        logger.warning("   │ ⚠️ Sesión expirada (401). Reautenticando e intentando una vez...")
        login()
        req_headers["Cookie"] = _sap_session["headers"]["Cookie"]
        resp = requests.request(
            method=method,
            url=url,
            json=json_data,
            params=params,
            headers=req_headers,
            timeout=SAPB1_TIMEOUT,
            verify=SAPB1_VERIFY_SSL,
        )

    _log_response(method, endpoint_path, resp, json_data)
    return resp


# ============================================================================
# SEND MESSAGE (POST /Messages)
# ============================================================================
def send_message(payload: dict) -> dict:
    resp = forward_to_sapb1("POST", "Messages", json_data=payload)
    if resp.status_code not in (200, 201):
        raise ConnectionError(
            f"   │ Error al enviar Mensaje: HTTP {resp.status_code} - {resp.text}"
        )
    result = resp.json()
    logger.info(f"   │ ✅ SAP B1 Service Layer - {resp.status_code}")
    return result