app/core/exceptions.py

# ============================================================
# app/core/exceptions.py - ALL Auth Exceptions
# ============================================================

from fastapi import HTTPException, status
from typing import Optional, Any, Dict

class AuthException(HTTPException):
    """Base authentication exception"""
    def __init__(
        self,
        status_code: int,
        detail: str,
        error_code: str,
        message: str,
        data: Optional[Dict[str, Any]] = None,
    ):
        super().__init__(status_code=status_code, detail=detail)
        self.error_code = error_code
        self.message = message
        self.data = data or {}

# ============================================================
# LOGIN ERRORS
# ============================================================

class InvalidCredentialsException(AuthException):
    """Invalid email/phone or password"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid credentials",
            error_code="INVALID_CREDENTIALS",
            message="The email/phone or password you entered is incorrect. Please try again.",
        )

class AccountInactiveException(AuthException):
    """Account is inactive"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Account is inactive",
            error_code="ACCOUNT_INACTIVE",
            message="Your account has been deactivated. Please contact support for assistance.",
        )

# ============================================================
# SIGNUP ERRORS
# ============================================================

class UserAlreadyExistsException(AuthException):
    """User already registered"""
    def __init__(self, identifier: str):
        super().__init__(
            status_code=status.HTTP_409_CONFLICT,
            detail="User already registered",
            error_code="USER_ALREADY_EXISTS",
            message="This email or phone number is already registered. Please log in instead.",
            data={"identifier": identifier},
        )

class SignupFailedException(AuthException):
    """Signup failed due to server error"""
    def __init__(self, reason: str = "Unknown error"):
        super().__init__(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Signup failed",
            error_code="SIGNUP_FAILED",
            message=f"Unable to create account. {reason} Please try again later.",
        )

class InvalidEmailFormatException(AuthException):
    """Invalid email format"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid email format",
            error_code="INVALID_EMAIL_FORMAT",
            message="Please enter a valid email address.",
        )

class InvalidPhoneFormatException(AuthException):
    """Invalid phone format"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid phone format",
            error_code="INVALID_PHONE_FORMAT",
            message="Please enter a valid phone number.",
        )

class WeakPasswordException(AuthException):
    """Password doesn't meet requirements"""
    def __init__(self, requirement: str):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Password doesn't meet requirements",
            error_code="WEAK_PASSWORD",
            message=f"Password must {requirement}. Please choose a stronger password.",
        )

class MissingEmailPhoneException(AuthException):
    """Neither email nor phone provided"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email or phone required",
            error_code="MISSING_EMAIL_PHONE",
            message="Please provide either an email address or a phone number.",
        )

# ============================================================
# OTP ERRORS
# ============================================================

class InvalidOtpException(AuthException):
    """Invalid OTP code"""
    def __init__(self, attempts_left: Optional[int] = None):
        msg = "The OTP code you entered is incorrect."
        if attempts_left is not None:
            msg += f" You have {attempts_left} attempt(s) left."
        
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid OTP code",
            error_code="INVALID_OTP",
            message=msg,
            data={"attempts_left": attempts_left} if attempts_left else {},
        )

class OtpExpiredException(AuthException):
    """OTP has expired"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="OTP expired",
            error_code="OTP_EXPIRED",
            message="The OTP code has expired. Please request a new one.",
        )

class OtpNotSentException(AuthException):
    """OTP was never sent"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="OTP not found",
            error_code="OTP_NOT_FOUND",
            message="No OTP was sent. Please request one first.",
        )

class OtpSendFailedException(AuthException):
    """Failed to send OTP"""
    def __init__(self, method: str = "email/SMS"):
        super().__init__(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="OTP send failed",
            error_code="OTP_SEND_FAILED",
            message=f"Failed to send OTP via {method}. Please try again later.",
        )

class OtpAlreadyValidException(AuthException):
    """OTP already validated/used"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="OTP already used",
            error_code="OTP_ALREADY_USED",
            message="This OTP has already been used. Please request a new one.",
        )

class OtpTooManyAttemptsException(AuthException):
    """Too many failed OTP attempts"""
    def __init__(self, retry_after_minutes: int = 15):
        super().__init__(
            status_code=status.HTTP_429_TOO_MANY_REQUESTS,
            detail="Too many OTP attempts",
            error_code="OTP_TOO_MANY_ATTEMPTS",
            message=f"Too many failed attempts. Please try again in {retry_after_minutes} minutes.",
            data={"retry_after_minutes": retry_after_minutes},
        )

# ============================================================
# PASSWORD RESET ERRORS
# ============================================================

class InvalidResetTokenException(AuthException):
    """Invalid reset token"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid reset token",
            error_code="INVALID_RESET_TOKEN",
            message="The reset token is invalid or has expired. Please request a password reset again.",
        )

class ResetTokenExpiredException(AuthException):
    """Reset token has expired"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Reset token expired",
            error_code="RESET_TOKEN_EXPIRED",
            message="The reset token has expired (valid for 10 minutes). Please request a new password reset.",
        )

class TokenMismatchException(AuthException):
    """Token identifier doesn't match request identifier"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Token mismatch",
            error_code="TOKEN_MISMATCH",
            message="The reset token doesn't match. Please request a new password reset.",
        )

class PasswordResetFailedException(AuthException):
    """Password reset failed"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Password reset failed",
            error_code="PASSWORD_RESET_FAILED",
            message="Unable to reset your password. Please try again later.",
        )

# ============================================================
# USER ERRORS
# ============================================================

class UserNotFoundException(AuthException):
    """User not found"""
    def __init__(self, identifier: str):
        super().__init__(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="User not found",
            error_code="USER_NOT_FOUND",
            message="No account found with this email or phone number. Please sign up first.",
            data={"identifier": identifier},
        )

class AccountNotVerifiedException(AuthException):
    """Account email/phone not verified"""
    def __init__(self, verification_type: str = "email"):
        super().__init__(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Account not verified",
            error_code="ACCOUNT_NOT_VERIFIED",
            message=f"Your {verification_type} has not been verified yet. Please verify to continue.",
            data={"verification_type": verification_type},
        )

class SamePasswordException(AuthException):
    """New password is same as old password"""
    def __init__(self):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Same password",
            error_code="SAME_PASSWORD",
            message="Your new password cannot be the same as your current password. Please choose a different one.",
        )

# ============================================================
# DATABASE ERRORS
# ============================================================

class DatabaseException(AuthException):
    """Database operation failed"""
    def __init__(self, operation: str = "operation"):
        super().__init__(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Database error",
            error_code="DATABASE_ERROR",
            message=f"A database error occurred during {operation}. Please try again later.",
        )

# ============================================================
# VALIDATION ERRORS
# ============================================================

class ValidationException(AuthException):
    """Validation error"""
    def __init__(self, message: str, errors: Optional[list] = None):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Validation error",
            error_code="VALIDATION_ERROR",
            message=message,
            data={"errors": errors} if errors else {},
        )

# ============================================================
# RATE LIMITING ERRORS
# ============================================================

class RateLimitException(AuthException):
    """Too many requests"""
    def __init__(self, retry_after_seconds: int = 60):
        super().__init__(
            status_code=status.HTTP_429_TOO_MANY_REQUESTS,
            detail="Too many requests",
            error_code="RATE_LIMIT_EXCEEDED",
            message=f"You've made too many requests. Please try again in {retry_after_seconds} seconds.",
            data={"retry_after_seconds": retry_after_seconds},
        )

# ============================================================
# RESEND OTP ERRORS
# ============================================================

class OtpResendTooSoonException(AuthException):
    """OTP resend requested too soon"""
    def __init__(self, wait_seconds: int = 60):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="OTP resend too soon",
            error_code="OTP_RESEND_TOO_SOON",
            message=f"Please wait {wait_seconds} seconds before requesting a new OTP.",
            data={"wait_seconds": wait_seconds},
        )

class OtpStillValidException(AuthException):
    """OTP is still valid, don't resend yet"""
    def __init__(self, expires_in_seconds: int):
        super().__init__(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="OTP still valid",
            error_code="OTP_STILL_VALID",
            message=f"Your current OTP is still valid. Please use it first (expires in {expires_in_seconds} seconds).",
            data={"expires_in_seconds": expires_in_seconds},
        )