from fastapi import APIRouter, Depends, HTTPException, status
from pydantic import BaseModel
import config
import auth
import pyotp

router = APIRouter()

class LoginRequest(BaseModel):
    username: str
    password: str
    totp_code: str = ""

class Token(BaseModel):
    access_token: str
    token_type: str
    user: str
    has_2fa: bool

class Setup2FAResponse(BaseModel):
    secret: str
    uri: str

class Verify2FARequest(BaseModel):
    secret: str
    code: str

@router.post("/login", response_model=Token)
async def login(creds: LoginRequest):
    # Verify username/password
    if creds.username != config.ADMIN_USER or not auth.verify_password(creds.password, auth.load_password_hash()):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    
    # Check 2FA
    totp_secret = auth.load_totp_secret()
    if totp_secret:
        if not creds.totp_code:
            raise HTTPException(
                status_code=status.HTTP_403_FORBIDDEN,
                detail="2FA code required",
                headers={"WWW-Authenticate": "Bearer"},
            )
        if not auth.verify_totp(creds.totp_code, totp_secret):
             raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Invalid 2FA code",
                headers={"WWW-Authenticate": "Bearer"},
            )

    access_token = auth.create_access_token(data={"sub": creds.username})
    return {
        "access_token": access_token, 
        "token_type": "bearer",
        "user": creds.username,
        "has_2fa": bool(totp_secret)
    }

@router.get("/me")
async def read_users_me(current_user: str = Depends(auth.get_current_user)):
    totp_secret = auth.load_totp_secret()
    return {"username": current_user, "has_2fa": bool(totp_secret)}

@router.post("/setup-2fa/generate", response_model=Setup2FAResponse)
async def generate_2fa(current_user: str = Depends(auth.get_current_user)):
    secret = pyotp.random_base32()
    uri = pyotp.totp.TOTP(secret).provisioning_uri(name=current_user, issuer_name="NAS Dashboard")
    return {"secret": secret, "uri": uri}

@router.post("/setup-2fa/verify")
async def verify_2fa_setup(request: Verify2FARequest, current_user: str = Depends(auth.get_current_user)):
    totp = pyotp.TOTP(request.secret)
    if not totp.verify(request.code):
        raise HTTPException(status_code=400, detail="Invalid code")
    
    # Save secret
    auth.save_totp_secret(request.secret)
    return {"message": "2FA enabled successfully"}
    
@router.post("/setup-2fa/disable")
async def disable_2fa(current_user: str = Depends(auth.get_current_user)):
    auth.save_totp_secret("")
    return {"message": "2FA disabled"}

class ChangePasswordRequest(BaseModel):
    current_password: str
    new_password: str

@router.post("/change-password")
async def change_password(req: ChangePasswordRequest, current_user: str = Depends(auth.get_current_user)):
    if not auth.verify_password(req.current_password, auth.load_password_hash()):
        raise HTTPException(status_code=400, detail="Current password is incorrect")
    if len(req.new_password) < 8:
        raise HTTPException(status_code=400, detail="Password must be at least 8 characters")
    auth.save_password_hash(auth.get_password_hash(req.new_password))
    return {"message": "Password changed successfully"}