import type { HttpContext } from '@adonisjs/core/http';
import User from '#models/user';
import BackupCode from '#models/backup_code';
import { authValidator } from '#validators/auth';
import hash from '@adonisjs/core/services/hash';
import db from '@adonisjs/lucid/services/db';
import TwoFactorAuthProvider from '#app/services/TwoFactorAuthProvider';
import ActivityLogger from '#services/activity_logger';
import logger from '@adonisjs/core/services/logger';

export default class AuthController {
    public async login({ request, response, auth, session }: HttpContext) {
        await request.validateUsing(authValidator);

        const { email, password } = request.only(['email', 'password']);

        try {
            await db.connection().rawQuery('SELECT 1');

            const user = await User.verifyCredentials(email, password);

            if (user.isTwoFactorEnabled) {
                // Noch KEIN abgeschlossenes Login -> nicht loggen.
                session.flash('user_id', user.id);
                return response.redirect().back();
            }

            await auth.use('web').login(user);
            this.recordAuthEvent('auth.login', { user, ip: request.ip() });
        } catch (error: any) {
            // DB nicht erreichbar -> kein fehlgeschlagener Login-Versuch, weiterwerfen
            if (error.code === 'ECONNREFUSED') {
                throw error;
            }

            // Echter Credential-Fehler -> als fehlgeschlagenen Versuch protokollieren
            this.recordAuthEvent('auth.login_failed', { email, ip: request.ip() });

            session.flash('message', 'Your username, email, or password is incorrect');
            return response.redirect().back();
        }

        return response.redirect('/apps/dashboard');
    }

    public async twoFactorChallenge({ request, session, auth, response }: HttpContext) {
        const { code, backup_code, login_id } = request.only(['code', 'backup_code', 'login_id']);
        const user = await User.query().where('id', login_id).firstOrFail();

        if (code) {
            const isValid = await TwoFactorAuthProvider.validate(user, code);
            if (isValid) {
                await auth.use('web').login(user);
                this.recordAuthEvent('auth.login', { user, email: user.email, ip: request.ip(), method: '2fa_totp' });
                return response.redirect('/apps/dashboard');
            }

            session.flash('message', 'Your two-factor code is incorrect');
            return response.redirect().back();
        }

        if (backup_code) {
            const codes: BackupCode[] = await user.getBackupCodes();

            let backupCodeToDelete: BackupCode | null = null;
            for (const backupCode of codes) {
                const isVerified = await hash.verify(backupCode.code, backup_code);
                if (isVerified) {
                    backupCodeToDelete = backupCode;
                    break;
                }
            }

            if (!backupCodeToDelete) {
                session.flash('message', 'BackupCode not found');
                return response.redirect().back();
            }

            if (backupCodeToDelete.used) {
                session.flash('message', 'BackupCode already used');
                return response.redirect().back();
            }

            backupCodeToDelete.used = true;
            await backupCodeToDelete.save();

            await auth.use('web').login(user);
            this.recordAuthEvent('auth.login', { user, email: user.email, ip: request.ip(), method: '2fa_backup_code' });

            return response.redirect('/apps/dashboard');
        }

        // Weder code noch backup_code übergeben
        session.flash('message', 'No verification code provided');
        return response.redirect().back();
    }

    public async logout({ auth, request, response }: HttpContext) {        
        // Session auflösen -> füllt auth.user, falls eingeloggt
        await auth.use('web').check();
        const user = auth.use('web').user;

        await auth.use('web').logout();

        if (user) {
            this.recordAuthEvent('auth.logout', { user, email: user.email, ip: request.ip() });
        }

        return response.redirect('/app/login');
    }

    /**
     * Zentraler Audit-Logger für Auth-Events.
     * Fire-and-forget: ein Fehler beim Schreiben darf Login/Logout nie blockieren.
     */
    private recordAuthEvent(
        type: 'auth.login' | 'auth.logout' | 'auth.login_failed',
        opts: { user?: User; email?: string; ip: string; method?: string },
    ) {
        const { user, email, ip, method } = opts;

        const description =
            type === 'auth.login'
                ? `${user!.firstName} ${user!.lastName} signed in`
                : type === 'auth.logout'
                    ? `${user!.firstName} ${user!.lastName} signed out`
                    : `Failed login attempt for ${email ?? 'unknown'}`;

        void ActivityLogger.log({
            type,
            description,
            userId: user?.id ?? null,
            subjectType: user ? 'User' : null,
            subjectId: user?.id ?? null,
            properties: { ip, ...(method ? { method } : {}) },
        }).catch((err) => logger.error({ err }, `failed to record ${type} activity`));
    }
}