import os
from datetime import datetime, timedelta, timezone

import pyotp
from fastapi import APIRouter, Depends, HTTPException, Request, Response, status

from app.services.infrastructure.rbac_service import rbac_service
from app.services.infrastructure.storage.database_service import db_service
from core.config import settings
from core.database import User
from core.logging import logger

from .schemas import (
    LoginRequest,
    MFASetupResponse,
    MFAVerifyRequest,
    MFAVerifyResponse,
    PasswordResetConfirm,
    PasswordResetRequest,
    RegisterRequest,
    RegisterResponse,
    SecurityMetrics,
    SessionInfo,
    UserProfileResponse,
)
from .service import auth_service

router = APIRouter()

# ===== AUTHENTICATION ENDPOINTS =====


@router.post(
    "/register", response_model=RegisterResponse, status_code=status.HTTP_201_CREATED
)
async def register(user_data: RegisterRequest):
    """
    Register a new user with password strength validation
    """
    try:
        # Validate password strength
        password_errors = auth_service.validate_password_strength(user_data.password)
        if password_errors:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail={
                    "message": "Password does not meet security requirements",
                    "errors": password_errors,
                },
            )

        # Check if username already exists
        existing_user = auth_service.get_user_by_username(user_data.username)
        if existing_user:
            raise HTTPException(
                status_code=status.HTTP_409_CONFLICT, detail="Username already exists"
            )

        # Check if email already exists
        existing_email = auth_service.get_user_by_email(user_data.email)
        if existing_email:
            raise HTTPException(
                status_code=status.HTTP_409_CONFLICT, detail="Email already registered"
            )

        # Create user
        new_user = auth_service.create_user(user_data)

        logger.info(f"New user registered: {new_user.username}")

        return {
            "user_id": new_user.id,
            "username": new_user.username,
            "email": new_user.email,
            "message": "User registered successfully",
            "created_at": new_user.created_at,
        }

    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Registration error: {e!s}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Registration error: {e!s}",
        )


@router.post("/login", response_model=UserProfileResponse)
async def login(login_data: LoginRequest, request: Request, response: Response):
    """
    Authenticate user and set HttpOnly cookies.
    """
    try:
        user = auth_service.authenticate_user(login_data.email, login_data.password)
        if not user:
            # Record failed login attempt
            try:
                from app.services.infrastructure.security_monitoring_service import (
                    security_monitoring,
                )

                await security_monitoring.record_login_attempt(
                    email=login_data.email,
                    user_id=None,
                    ip_address=request.client.host or "unknown",
                    user_agent=request.headers.get("user-agent", ""),
                    success=False,
                    failure_reason="Invalid credentials",
                )
            except Exception as e:
                logger.warning(f"Failed to record login attempt: {e}")

            logger.warning(
                f"Failed login attempt for email: {login_data.email} from IP: {request.client.host if request.client else 'unknown'}"
            )
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Invalid username or password",
            )

        # CHECK MFA
        mfa_required = user.mfa_enabled

        # Enforce MFA for admins if configured in production
        if (
            not mfa_required
            and user.role in ["admin", "superuser"]
            and getattr(settings, "mfa_required_for_admin", False)
        ):
            # In production, we require MFA for administrative roles
            logger.info(
                f"MFA enforcement: Requiring MFA for admin user {user.username}"
            )
            mfa_required = True

        if mfa_required:
            # If MFA enabled or required and no code provided, return 403 to trigger frontend prompt
            if not login_data.mfa_code:
                raise HTTPException(
                    status_code=status.HTTP_403_FORBIDDEN, detail="MFA code required"
                )

            if not user.mfa_secret:
                logger.error(f"User {user.username} has MFA enabled but no secret")
                raise HTTPException(status_code=500, detail="MFA configuration error")

            totp = pyotp.TOTP(user.mfa_secret)
            if not totp.verify(login_data.mfa_code):
                logger.warning(f"Invalid MFA code for user {user.username}")
                raise HTTPException(
                    status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid MFA code"
                )

        # Record successful login attempt
        try:
            from app.services.infrastructure.security_monitoring_service import (
                security_monitoring,
            )

            await security_monitoring.record_login_attempt(
                email=user.email,
                user_id=user.id,
                ip_address=request.client.host or "unknown",
                user_agent=request.headers.get("user-agent", ""),
                success=True,
            )
        except Exception as e:
            logger.warning(f"Failed to record successful login: {e}")

        logger.info(
            f"Successful login for user: {user.username} (ID: {user.id}) from IP: {request.client.host if request.client else 'unknown'}"
        )

        # Track user journey
        try:
            from app.services.business.user_journey_tracker import user_journey_tracker

            user_journey_tracker.track_event(
                user_id=user.id,
                event_type="login",
                metadata={"role": user.role, "mfa": user.mfa_enabled},
            )
        except Exception as e:
            logger.warning(f"Failed to track user journey event: {e}")

        # Create tokens
        access_token = auth_service.create_access_token(
            {
                "sub": user.id,
                "username": user.username,
                "role": user.role,
                "mfa_verified": user.mfa_enabled,
            }
        )
        refresh_token = auth_service.create_refresh_token(user.id)

        # Create session record
        try:
            from app.services.infrastructure.security_monitoring_service import (
                security_monitoring,
            )

            await security_monitoring.create_user_session(
                user_id=user.id,
                session_token=refresh_token,
                ip_address=request.client.host or "unknown",
                user_agent=request.headers.get("user-agent", ""),
                expires_at=datetime.now(timezone.utc) + timedelta(days=7),
            )
        except Exception as e:
            logger.warning(f"Failed to create session record: {e}")

        # Set HttpOnly Cookies
        # Set HttpOnly Cookies
        # Secure=True in production (HTTPS), False in dev if needed
        is_production = os.getenv("ENVIRONMENT", "development").lower() == "production"
        secure_cookie = is_production

        response.set_cookie(
            key="access_token",
            value=access_token,
            httponly=True,
            secure=secure_cookie,
            samesite="strict",
            max_age=1800,  # 30 minutes
        )

        response.set_cookie(
            key="refresh_token",
            value=refresh_token,
            httponly=True,
            secure=secure_cookie,
            samesite="strict",
            path="/api/v1/auth/refresh",
            max_age=7 * 24 * 60 * 60,  # 7 days
        )

        return {
            "id": user.id,
            "username": user.username,
            "email": user.email,
            "full_name": user.full_name,
            "role": user.role,
            "is_active": user.is_active,
            "mfa_enabled": user.mfa_enabled,
            "created_at": user.created_at,
            "last_login": user.last_login,
        }

    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Login error: {e!s}")
        raise HTTPException(status_code=500, detail="Internal login error")


@router.get("/mfa/setup", response_model=MFASetupResponse)
async def mfa_setup(current_user: User = Depends(auth_service.get_current_user)):
    """Generate MFA secret and QR code URI for setup"""
    if current_user.mfa_enabled:
        raise HTTPException(status_code=400, detail="MFA is already enabled")

    # Generate secret
    secret = pyotp.random_base32()

    # Save secret to DB (but don't enable yet)
    # We must fetch a fresh user instance attached to a session to update
    with db_service.get_db() as db:
        user = db.query(User).filter(User.id == current_user.id).first()
        if not user:
            raise HTTPException(status_code=404, detail="User not found")

        user.mfa_secret = secret
        db.commit()

    # Generate Provisioning URI
    uri = pyotp.totp.TOTP(secret).provisioning_uri(
        name=current_user.email, issuer_name="Zenith Fraud Platform"
    )

    return {"secret": secret, "otpauth_url": uri}


@router.post("/mfa/verify", response_model=MFAVerifyResponse)
async def mfa_verify(
    verify_data: MFAVerifyRequest,
    current_user: User = Depends(auth_service.get_current_user),
):
    """Verify MFA code and enable MFA for the account"""
    if current_user.mfa_enabled:
        return {"message": "MFA is already enabled"}

    # We need the secret from the DB
    # Fetch fresh user
    with db_service.get_db() as db:
        user = db.query(User).filter(User.id == current_user.id).first()
        if not user or not user.mfa_secret:
            raise HTTPException(
                status_code=400, detail="MFA setup not initiated (no secret found)"
            )

        totp = pyotp.TOTP(user.mfa_secret)
        if not totp.verify(verify_data.code):
            raise HTTPException(status_code=400, detail="Invalid code")

        # Enable MFA
        user.mfa_enabled = True
        db.commit()

    logger.info(f"MFA enabled for user {current_user.username}")
    return {"message": "MFA enabled successfully"}


@router.post("/refresh")
async def refresh_token(request: Request, response: Response):
    """
    Refresh access token using HttpOnly cookie.
    """
    refresh_token = request.cookies.get("refresh_token")
    if not refresh_token:
        raise HTTPException(status_code=401, detail="Refresh cookie missing")

    try:
        # Verify refresh token
        payload = auth_service.decode_token(refresh_token)
        if payload.get("type") != "refresh":
            raise HTTPException(status_code=401, detail="Invalid token type")

        user_id = payload.get("sub")

        # Determine claims
        # We can just call get_user directly from db_service as we have the ID, or use auth_service helper?
        # auth_service.get_user isn't explicitly defined above in the new file, it was just db_service.get_user wrapped
        # But auth_service.get_current_user does it.
        # Let's use db_service directly here for clarity or add a helper to auth_service.
        # The original code had: user = auth_service.get_user(user_id) if hasattr(auth_service, "get_user") else None
        # Let's fix this properly.
        user = db_service.get_user_by_id(user_id)

        if not user:
            # Security fix: Do not issue tokens for non-existent/inactive users
            # Previously this fell back to "unknown" user which allowed access after deletion
            logger.warning(f"Refresh attempt for non-existent user: {user_id}")
            raise HTTPException(
                status_code=401, detail="User no longer exists or is inactive"
            )

        claims = {
            "sub": user_id,
            "username": user.username,
            "role": user.role,
            "mfa_verified": user.mfa_enabled,
        }

        new_access_token = auth_service.create_access_token(claims)

        # Set new access token cookie
        response.set_cookie(
            key="access_token",
            value=new_access_token,
            httponly=True,
            secure=True,
            samesite="strict",
            max_age=1800,  # 30 minutes
        )

        return {"message": "Token refreshed"}

    except Exception as e:
        logger.warning(f"Refresh failed: {e}")
        # Clear cookies on failure
        response.delete_cookie("access_token")
        response.delete_cookie("refresh_token", path="/api/v1/auth/refresh")
        raise HTTPException(status_code=401, detail="Invalid refresh token")


@router.post("/logout")
async def logout(response: Response):
    """
    Logout user by clearing cookies.
    """
    response.delete_cookie("access_token")
    response.delete_cookie("refresh_token", path="/api/v1/auth/refresh")
    return {"message": "Logged out successfully"}


@router.get("/me", response_model=UserProfileResponse)
async def get_current_user_profile(
    current_user: User = Depends(auth_service.get_current_user),
):
    """Get current user profile"""
    return {
        "id": current_user.id,
        "username": current_user.username,
        "email": current_user.email,
        "full_name": current_user.full_name,
        "role": current_user.role,
        "is_active": current_user.is_active,
        "mfa_enabled": current_user.mfa_enabled,
        "created_at": current_user.created_at,
        "last_login": current_user.last_login,
    }


# ===== PASSWORD RESET ENDPOINTS =====


@router.post("/password/reset-request")
async def request_password_reset(request_data: PasswordResetRequest):
    """
    Request a password reset link via email
    """
    try:
        # Check if user exists
        user = auth_service.get_user_by_email(request_data.email)
        if not user:
            # Don't reveal if email exists for security
            logger.info(
                f"Password reset requested for unknown email: {request_data.email}"
            )
            return {"message": "If the email exists, a reset link has been sent"}

        # Generate reset token (expires in 1 hour)
        reset_token = auth_service.create_access_token(
            {"sub": user.id, "type": "password_reset"}, expires_delta=timedelta(hours=1)
        )

        # Send email with reset link
        reset_url = f"{os.getenv('FRONTEND_URL', 'http://localhost:3000')}/reset-password?token={reset_token}"

        # Import email service
        try:
            from app.services.infrastructure.email_service import email_service

            email_sent = await email_service.send_password_reset_email(
                user.email, reset_url
            )
            if not email_sent:
                logger.warning(f"Failed to send password reset email to {user.email}")
        except ImportError:
            logger.warning("Email service not available, logging reset URL instead")
            logger.info(f"Password reset URL for {user.email}: {reset_url}")

        # In production, integrate with email service:
        # await email_service.send_password_reset(user.email, reset_url)

        return {"message": "If the email exists, a reset link has been sent"}

    except Exception as e:
        logger.error(f"Password reset request error: {e}")
        # Don't reveal internal errors for security
        return {"message": "If the email exists, a reset link has been sent"}


@router.post("/password/reset")
async def reset_password(request_data: PasswordResetConfirm):
    """
    Reset password using reset token
    """
    try:
        # Verify token
        payload = auth_service.decode_token(request_data.token)
        if payload.get("type") != "password_reset":
            raise HTTPException(status_code=400, detail="Invalid reset token")

        user_id = payload.get("sub")
        user = db_service.get_user_by_id(user_id)
        if not user:
            raise HTTPException(status_code=400, detail="Invalid reset token")

        # Validate new password
        password_errors = auth_service.validate_password_strength(request_data.password)
        if password_errors:
            raise HTTPException(
                status_code=400,
                detail={
                    "message": "Password does not meet security requirements",
                    "errors": password_errors,
                },
            )

        # Update password
        hashed_password = auth_service.hash_password(request_data.password)
        with db_service.get_db() as db:
            db_user = db.query(User).filter(User.id == user_id).first()
            db_user.password_hash = hashed_password
            db_user.updated_at = datetime.now(timezone.utc)
            db.commit()

        logger.info(f"Password reset successful for user: {user.email}")

        # Send confirmation email
        try:
            from app.services.infrastructure.email_service import email_service

            await email_service.send_password_reset_confirmation(user.email)
        except Exception as e:
            logger.warning(f"Failed to send password reset confirmation email: {e}")

        return {"message": "Password reset successfully"}

    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Password reset error: {e}")
        raise HTTPException(status_code=500, detail="Password reset failed")


# ===== SESSION MANAGEMENT ENDPOINTS =====


@router.get("/sessions", response_model=list[SessionInfo])
async def get_user_sessions(
    current_user: User = Depends(auth_service.get_current_user),
):
    """
    Get all active sessions for the current user
    """
    try:
        from app.services.infrastructure.security_monitoring_service import (
            security_monitoring,
        )

        sessions = await security_monitoring.get_user_sessions(current_user.id)
        return sessions
    except Exception as e:
        logger.error(f"Failed to get user sessions: {e}")
        return []


@router.delete("/sessions/{session_id}")
async def revoke_session(
    session_id: str,
    current_user: User = Depends(auth_service.get_current_user),
):
    """
    Revoke a specific session
    """
    try:
        from app.services.infrastructure.security_monitoring_service import (
            security_monitoring,
        )

        success = await security_monitoring.revoke_session(session_id, current_user.id)

        if not success:
            raise HTTPException(status_code=404, detail="Session not found")

        return {"message": "Session revoked successfully"}

    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Failed to revoke session: {e}")
        raise HTTPException(status_code=500, detail="Failed to revoke session")


@router.delete("/sessions")
async def revoke_all_other_sessions(
    current_user: User = Depends(auth_service.get_current_user),
):
    """
    Revoke all sessions except the current one
    """
    try:
        from app.services.infrastructure.security_monitoring_service import (
            security_monitoring,
        )

        count = await security_monitoring.revoke_all_user_sessions(
            current_user.id, except_current=True
        )

        logger.info(
            f"All other sessions revoked for user: {current_user.email} ({count} sessions)"
        )
        return {
            "message": f"All other sessions revoked successfully ({count} sessions)"
        }

    except Exception as e:
        logger.error(f"Failed to revoke all sessions: {e}")
        raise HTTPException(status_code=500, detail="Failed to revoke sessions")


# ===== SECURITY MONITORING ENDPOINTS =====


@router.get("/admin/security/metrics", response_model=SecurityMetrics)
async def get_security_metrics(
    current_user: User = Depends(rbac_service.require_role("admin")),
):
    """
    Get security metrics and login attempt statistics (Admin only)
    """
    try:
        from app.services.infrastructure.security_monitoring_service import (
            security_monitoring,
        )

        metrics = await security_monitoring.get_security_metrics()
        return metrics

    except Exception as e:
        logger.error(f"Failed to get security metrics: {e}")
        raise HTTPException(
            status_code=500, detail="Failed to retrieve security metrics"
        )


@router.get("/admin/security/login-attempts")
async def get_login_attempts(
    limit: int = 50,
    offset: int = 0,
    current_user: User = Depends(rbac_service.require_role("admin")),
):
    """
    Get detailed login attempt logs (Admin only)
    """
    try:
        # Get recent attempts from security monitoring service
        from app.services.infrastructure.security_monitoring_service import (
            security_monitoring,
        )

        metrics = await security_monitoring.get_security_metrics()

        attempts = metrics.get("recent_attempts", [])
        total = len(attempts)

        return {
            "attempts": attempts[offset : offset + limit],
            "total": total,
            "limit": limit,
            "offset": offset,
        }

    except Exception as e:
        logger.error(f"Failed to get login attempts: {e}")
        raise HTTPException(status_code=500, detail="Failed to retrieve login attempts")