from datetime import datetime, timedelta
from passlib.context import CryptContext
from jose import JWTError, jwt, ExpiredSignatureError
from fastapi import HTTPException, status
from app.config import settings

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")


def hash_api_key(key: str) -> str:
    return pwd_context.hash(key)


def verify_api_key(plain: str, hashed: str) -> bool:
    return pwd_context.verify(plain, hashed)


def hash_password(password: str) -> str:
    return pwd_context.hash(password)


def verify_password(plain: str, hashed: str) -> bool:
    return pwd_context.verify(plain, hashed)


def create_access_token(client_id: str, scopes: list) -> str:
    expire = datetime.utcnow() + timedelta(minutes=settings.JWT_EXPIRE_MINUTES)
    payload = {
        "sub": client_id,
        "scopes": scopes,
        "type": "api",
        "exp": expire,
        "iat": datetime.utcnow(),
    }
    return jwt.encode(payload, settings.SECRET_KEY, algorithm=settings.JWT_ALGORITHM)


def create_session_token(client_id: str, expire_days: int = 7) -> str:
    expire = datetime.utcnow() + timedelta(days=expire_days)
    payload = {
        "sub": client_id,
        "type": "session",
        "exp": expire,
        "iat": datetime.utcnow(),
    }
    return jwt.encode(payload, settings.SECRET_KEY, algorithm=settings.JWT_ALGORITHM)


def create_purpose_token(client_id: str, purpose: str, expire_hours: int = 72) -> str:
    """Token de un solo propósito (ej. 'pwd_set') para links de correo de un solo uso."""
    expire = datetime.utcnow() + timedelta(hours=expire_hours)
    payload = {
        "sub": client_id,
        "type": purpose,
        "exp": expire,
        "iat": datetime.utcnow(),
    }
    return jwt.encode(payload, settings.SECRET_KEY, algorithm=settings.JWT_ALGORITHM)


def decode_token(token: str) -> dict:
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[settings.JWT_ALGORITHM])
        return payload
    except ExpiredSignatureError:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Token expirado",
            headers={"WWW-Authenticate": "Bearer"},
        )
    except JWTError:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Token inválido",
            headers={"WWW-Authenticate": "Bearer"},
        )