from datetime import datetime, timedelta, timezone
from typing import Optional
from jose import JWTError, jwt
from app.core.config import settings
from fastapi import Response
from passlib.context import CryptContext

# 密码加密上下文
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

def create_access_token(data: dict, expires_delta: Optional[timedelta] = None) -> str:
    to_encode = data.copy()

    to_encode = {
        "sub": data.get("phone")
    }
    if expires_delta:
        to_encode.update({"exp": datetime.now(timezone.utc) + expires_delta})
    else:
        to_encode.update({"exp": datetime.now(timezone.utc) + timedelta(days=180)})
    
    encoded_jwt = jwt.encode(to_encode, settings.SECRET_KEY, algorithm="HS256")
    return encoded_jwt

def set_jwt_cookie(response: Response, token: str):
    """设置JWT cookie"""
    response.set_cookie(
        key="access_token",
        value=token,
        httponly=True,  # 防止JavaScript访问
        secure=not settings.DEBUG,  # 生产环境使用HTTPS
        samesite="Lax",  # CSRF保护
        expires=datetime.now(timezone.utc) + timedelta(days=180),
        max_age=180*24*60*60  # 30天的秒数
    )

def clear_jwt_cookie(response: Response):
    """清除JWT cookie"""
    response.delete_cookie(
        key="access_token",
        httponly=True,
        # secure=not settings.DEBUG,
        samesite="lax"
    )

def verify_token(token: str) -> Optional[str]:
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=["HS256"])
        sub: str = payload.get("sub")
        print(f"payload: {payload}")
        return sub
    except JWTError:
        return None

def get_password_hash(password: str) -> str:
    """获取密码哈希值"""
    return pwd_context.hash(password)

def verify_password(plain_password: str, hashed_password: str) -> bool:
    """验证密码"""
    return pwd_context.verify(plain_password, hashed_password) 

def decode_jwt(token: str) -> dict:
    """解码 JWT token 获取完整信息"""
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=["HS256"])
        return {
            "phone": payload.get("sub"),
        }
    except:
        return None