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


# ============================================================================
# CONFIGURACIÓN
# ============================================================================

urllib3.disable_warnings()

load_dotenv(dotenv_path=".env.dev")

SAPB1_URL = os.getenv("SAP_B1_URL", "")
SAPB1_USER = os.getenv("SAP_B1_USER", "")
SAPB1_PASSWORD = os.getenv("SAP_B1_PASSWORD", "")
SAPB1_COMPANY = os.getenv("SAP_B1_COMPANY", "")
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}


# ============================================================================
# LOGIN
# ============================================================================
def login() -> dict:
    payload = {
        "CompanyDB": SAPB1_COMPANY,
        "UserName": SAPB1_USER,
        "Password": SAPB1_PASSWORD,
    }
    print("🔐 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})
    print(f"✅ Sesión SAP B1 establecida (B1SESSION: {b1session[:10]}...)")
    return headers


# ============================================================================
# LOGOUT
# ============================================================================
def logout() -> None:
    if not _sap_session["b1session"]:
        print("⚠️ No hay sesión activa para cerrar.")
        return
    print("🔓 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:
            print("✅ Sesión SAP B1 cerrada correctamente.")
        else:
            print(f"⚠️ Logout respondió HTTP {resp.status_code}")
    except Exception as exc:
        print(f"❌ Error al cerrar sesión: {exc}")
    finally:
        _sap_session.update({"headers": None, "b1session": None, "routeid": None})


# ============================================================================
# SESIÓN (interna - lazy login)
# ============================================================================
def _ensure_session() -> dict:
    if _sap_session["headers"]:
        return _sap_session["headers"]
    return login()


# ============================================================================
# LOGGING DE RESPUESTA
# ============================================================================
def _log_response(method: str, endpoint: str, response: requests.Response, payload: Any = None) -> None:
    log_line = (
        f"   ├── [{method}] {endpoint} → {response.status_code}"
        f" ({len(response.content)} bytes)"
    )
    if response.status_code >= 400:
        print("⚠️ %s - %s", log_line, response.text[:300])
    else:
        print(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,
    extra_headers: Optional[Dict[str, str]] = 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"],
    }

    if extra_headers:
        req_headers.update(extra_headers)

    print(f"   ├── 🔄 [{method}] {endpoint_path}")

    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:
        print("⚠️ Sesión expirada (401). Reautenticando e intentando una vez...")
        req_headers["Cookie"] = login()["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)

    if resp.status_code >= 400:
        try:
            error_body = resp.json()
            sap_message = (
                error_body.get("error", {})
                .get("message", {})
                .get("value", resp.text)
            )
        except (json.JSONDecodeError, AttributeError):
            sap_message = resp.text
        raise ConnectionError(
            f"Error en SAP {method} {endpoint_path}: "
            f"HTTP {resp.status_code} - {sap_message}"
        )

    return resp


# ============================================================================
# CREAR DRAFT (POST /Drafts)
# ============================================================================
def create_draft(payload: dict) -> dict:
    resp = forward_to_sapb1("POST", "Drafts", json_data=payload)
    result = resp.json()
    print(f"   ├── ✅ Draft creado  DocEntry={result.get('DocEntry')}")
    return result


# ============================================================================
# OBTENER FACTURA DE COMPRA (GET /PurchaseInvoices(DocEntry))
# ============================================================================
def get_purchase_invoice(doc_entry: int) -> dict:
    resp = forward_to_sapb1("GET", f"PurchaseInvoices({doc_entry})")
    result = resp.json()
    print(f"   ├── ✅ PurchaseInvoices({doc_entry}) obtenida")
    return result

# ============================================================================
# OBTENER GUIA (GET /DeliveryNotes)
# ============================================================================
def get_delivery_notes(tipo: str, serie: str, numero: str) -> list:
    filter_str = (
        f"Cancelled eq 'tNO'"
        f" and U_BPP_MDSD eq '{tipo}'"
        f" and U_BPP_MDTD eq '{serie}'"
        f" and contains(U_BPP_MDCD,'{numero}')"
    )
    resp = forward_to_sapb1("GET", "DeliveryNotes", params={"$filter": filter_str})
    result = resp.json()
    value = result.get("value", [])
    print(f"   ├── ✅ DeliveryNotes obtenida ({len(value)} registros)")
    return value

# ============================================================================
# OBTENER ZONAS (GET /U_IDC_ZONAS)
# ============================================================================
def get_zonas() -> list:
    
    filter_str = (
        f"U_Activo eq 'Y'"
    )

    sap_params = {
        "$skip": "0",
        "$top": "100",
        "$inlinecount": "allpages"
    }

    sap_params["$select"] = "Code, Name"

    base_headers = {"B1S-PageSize": "100"}

    if filter_str:
        sap_params["$filter"] = filter_str

    resp = forward_to_sapb1(
        method="GET"
        , endpoint_path="U_IDC_ZONAS"
        , params=sap_params
        , extra_headers=base_headers
    )
    result = resp.json()
    value = result.get("value", [])
    print(f"   ├── ✅ U_IDC_ZONAS obtenida ({len(value)} registros)")
    return value