## Copyright © 2026 Olaf Kolkman
## SPDX-License-Identifier: GPL-3.0-or-later

from uuid import uuid4

from fastapi import APIRouter, Depends, Header, HTTPException, Request
from pydantic import BaseModel

from backend.app.api.dependencies import get_current_user
from backend.app.database import get_connection, init_db
from backend.app.core.config import settings
from backend.app.services.auth_service import authenticate_user, find_user
from backend.app.services.email_service import send_password_reset_email, smtp_configured
from backend.app.services.email_verification import verify_email
from backend.app.services.password_reset import create_reset_token, reset_password
from backend.app.services.token_service import issue_token, revoke_token, rotate_refresh_token, validate_token
from backend.app.services.otp_service import verify_code
from backend.app.services.secret_store import decrypt_secret
from backend.app.services.email_addresses import verify_user_email_address
from backend.app.services.login_throttle import check_login_allowed, clear_login_failures, record_login_failure

router = APIRouter()

init_db()


class LoginRequest(BaseModel):
    email: str
    password: str
    otp: str | None = None
    device_id: str | None = None


class RefreshTokenRequest(BaseModel):
    refresh_token: str
    device_id: str | None = None


class PasswordResetRequest(BaseModel):
    token: str
    password: str


@router.post('/login')
def login(payload: LoginRequest, request: Request):
    email = payload.email.strip()
    ip_address = request.client.host if request.client else 'unknown'
    retry_after = check_login_allowed(ip_address, email)
    if retry_after is not None:
        raise HTTPException(status_code=429, detail='Too many failed login attempts. Try again later.', headers={'Retry-After': str(retry_after)})

    user = authenticate_user(email, payload.password)
    if user is None:
        record_login_failure(ip_address, email)
        reset_user = find_user(email)
        if reset_user and reset_user['email_verified'] and smtp_configured():
            try:
                token = create_reset_token(reset_user['id'])
                reset_url = f'{settings.public_url}/reset-password?token={token}'
                send_password_reset_email(reset_user['email'], reset_user['username'], reset_url)
            except Exception:
                pass
        raise HTTPException(status_code=401, detail='Invalid username or password')
    if not user['email_verified']:
        raise HTTPException(status_code=403, detail='Email address is not verified')
    if user['otp_enabled'] and not verify_code(decrypt_secret(user['otp_secret']), payload.otp):
        record_login_failure(ip_address, email)
        raise HTTPException(status_code=401, detail='One-time password required or invalid')

    clear_login_failures(ip_address, email)
    token_data = issue_token(user['id'], user['username'], payload.device_id)
    return {
        'access_token': token_data['access_token'],
        'token_type': 'bearer',
        'expires_at': token_data['expires_at'],
        'refresh_token': token_data['refresh_token'],
        'device_id': token_data['device_id'],
        'user': {'id': user['id'], 'username': user['username'], 'email': user['email'], 'otp_enabled': bool(user['otp_enabled'])}
    }


@router.post('/refresh')
def refresh_token_endpoint(payload: RefreshTokenRequest):
    rotated = rotate_refresh_token(payload.refresh_token, payload.device_id)
    if rotated is None:
        raise HTTPException(status_code=401, detail='Refresh token is invalid, expired, or bound to another device')
    return {
        'access_token': rotated['access_token'],
        'token_type': 'bearer',
        'expires_at': rotated['expires_at'],
        'refresh_token': rotated['refresh_token'],
        'device_id': rotated['device_id'],
        'user': {'id': rotated['user_id'], 'username': rotated['username']},
    }


@router.get('/verify-email')
def verify_email_address(token: str):
    if not verify_email(token):
        raise HTTPException(status_code=400, detail='Verification link is invalid or expired')
    return {'status': 'verified', 'message': 'Email address verified. You can now sign in.'}


@router.get('/verify-additional-email')
def verify_additional_email_address(token: str):
    if not verify_user_email_address(token):
        raise HTTPException(status_code=400, detail='Email verification link is invalid or expired')
    return {'status': 'verified', 'message': 'Email address verified. You can now sign in.'}



@router.post('/reset-password')
def reset_password_endpoint(payload: PasswordResetRequest):
    if len(payload.password) < 8:
        raise HTTPException(status_code=422, detail='Password must contain at least 8 characters')
    if not reset_password(payload.token, payload.password):
        raise HTTPException(status_code=400, detail='Password reset link is invalid or expired')
    return {'status': 'password_reset', 'message': 'Password reset. You can now sign in.'}


@router.post('/logout')
def logout(authorization: str | None = Header(default=None)):
    if not authorization or not authorization.startswith('Bearer '):
        raise HTTPException(status_code=401, detail='Missing or invalid Authorization header')
    token = authorization.replace('Bearer ', '', 1).strip()
    if not token:
        raise HTTPException(status_code=401, detail='Missing or invalid Authorization header')
    revoked = revoke_token(token)
    if not revoked:
        raise HTTPException(status_code=404, detail='Token not found or already revoked')
    return {'status': 'logged_out'}


@router.get('/me')
def current_user(user: dict = Depends(get_current_user)):
    return {
        'id': user['id'],
        'username': user['username'],
        'email': user['email'],
        'is_admin': bool(user['is_admin']),
    }