"""
User authentication models and validation for OpenManus
Mobile number + password based authentication system
"""

import hashlib
import re
import secrets
from datetime import datetime, timedelta
from typing import Optional
from dataclasses import dataclass
from pydantic import BaseModel, validator


class UserSignupRequest(BaseModel):
    """User signup request model"""

    full_name: str
    mobile_number: str
    password: str
    confirm_password: str

    @validator("full_name")
    def validate_full_name(cls, v):
        if not v or len(v.strip()) < 2:
            raise ValueError("Full name must be at least 2 characters long")
        if len(v.strip()) > 100:
            raise ValueError("Full name must be less than 100 characters")
        return v.strip()

    @validator("mobile_number")
    def validate_mobile_number(cls, v):
        # Remove all non-digit characters
        digits_only = re.sub(r"\D", "", v)

        # Check if it's a valid mobile number (10-15 digits)
        if len(digits_only) < 10 or len(digits_only) > 15:
            raise ValueError("Mobile number must be between 10-15 digits")

        # Ensure it starts with country code or local format
        if not re.match(r"^(\+?[1-9]\d{9,14})$", digits_only):
            raise ValueError("Invalid mobile number format")

        return digits_only

    @validator("password")
    def validate_password(cls, v):
        if len(v) < 8:
            raise ValueError("Password must be at least 8 characters long")
        if len(v) > 128:
            raise ValueError("Password must be less than 128 characters")

        # Check for at least one uppercase, lowercase, and digit
        if not re.search(r"[A-Z]", v):
            raise ValueError("Password must contain at least one uppercase letter")
        if not re.search(r"[a-z]", v):
            raise ValueError("Password must contain at least one lowercase letter")
        if not re.search(r"\d", v):
            raise ValueError("Password must contain at least one digit")

        return v

    @validator("confirm_password")
    def validate_confirm_password(cls, v, values):
        if "password" in values and v != values["password"]:
            raise ValueError("Passwords do not match")
        return v


class UserLoginRequest(BaseModel):
    """User login request model"""

    mobile_number: str
    password: str

    @validator("mobile_number")
    def validate_mobile_number(cls, v):
        # Remove all non-digit characters
        digits_only = re.sub(r"\D", "", v)

        if len(digits_only) < 10 or len(digits_only) > 15:
            raise ValueError("Invalid mobile number")

        return digits_only


@dataclass
class User:
    """User model"""

    id: str
    mobile_number: str
    full_name: str
    password_hash: str
    avatar_url: Optional[str] = None
    preferences: Optional[str] = None
    is_active: bool = True
    created_at: Optional[datetime] = None
    updated_at: Optional[datetime] = None


@dataclass
class UserSession:
    """User session model"""

    session_id: str
    user_id: str
    mobile_number: str
    full_name: str
    created_at: datetime
    expires_at: datetime

    @property
    def is_valid(self) -> bool:
        """Check if session is still valid"""
        return datetime.utcnow() < self.expires_at


class UserAuth:
    """User authentication utilities"""

    @staticmethod
    def hash_password(password: str) -> str:
        """Hash password using SHA-256 with salt"""
        salt = secrets.token_hex(32)
        password_hash = hashlib.sha256((password + salt).encode()).hexdigest()
        return f"{salt}:{password_hash}"

    @staticmethod
    def verify_password(password: str, password_hash: str) -> bool:
        """Verify password against stored hash"""
        try:
            salt, stored_hash = password_hash.split(":")
            password_hash_check = hashlib.sha256((password + salt).encode()).hexdigest()
            return password_hash_check == stored_hash
        except ValueError:
            return False

    @staticmethod
    def generate_session_id() -> str:
        """Generate secure session ID"""
        return secrets.token_urlsafe(32)

    @staticmethod
    def generate_user_id() -> str:
        """Generate unique user ID"""
        return f"user_{secrets.token_hex(16)}"

    @staticmethod
    def format_mobile_number(mobile_number: str) -> str:
        """Format mobile number for consistent storage"""
        # Remove all non-digit characters
        digits_only = re.sub(r"\D", "", mobile_number)

        # Add + prefix if not present and format consistently
        if not digits_only.startswith("+"):
            # Assume it's a local number, add default country code if needed
            if len(digits_only) == 10:  # US format
                digits_only = f"1{digits_only}"

        return f"+{digits_only}"

    @staticmethod
    def create_session(user: User, duration_hours: int = 24) -> UserSession:
        """Create a new user session"""
        session_id = UserAuth.generate_session_id()
        created_at = datetime.utcnow()
        expires_at = created_at + timedelta(hours=duration_hours)

        return UserSession(
            session_id=session_id,
            user_id=user.id,
            mobile_number=user.mobile_number,
            full_name=user.full_name,
            created_at=created_at,
            expires_at=expires_at,
        )


# Response models
class AuthResponse(BaseModel):
    """Authentication response model"""

    success: bool
    message: str
    session_id: Optional[str] = None
    user_id: Optional[str] = None
    full_name: Optional[str] = None


class UserProfile(BaseModel):
    """User profile response model"""

    user_id: str
    full_name: str
    mobile_number: str  # Masked for security
    avatar_url: Optional[str] = None
    created_at: Optional[str] = None

    @staticmethod
    def mask_mobile_number(mobile_number: str) -> str:
        """Mask mobile number for security (show only last 4 digits)"""
        if len(mobile_number) <= 4:
            return "*" * len(mobile_number)
        return "*" * (len(mobile_number) - 4) + mobile_number[-4:]