/*
 * Copyright (C) 2024-present Puter Technologies Inc.
 *
 * This file is part of Puter.
 *
 * Puter is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

import bcrypt from 'bcrypt';
import crypto from 'node:crypto';
import { v4 as uuidv4 } from 'uuid';
import { PuterService } from '../types.js';
import type { UserRow } from '../../stores/user/UserStore.js';
import { provisionUser } from '../../util/userProvisioning.js';
import { LOCAL_UNLIMITED_USER } from '../../data/subPolicies/localUnlimitedUserPolicy.js';
import { UNLIMITED_SUBSCRIPTION } from '../metering/consts.js';

const USERNAME = 'admin';
export const ADMIN_GROUP_UID = 'ca342a5e-b13d-4dee-9048-58b11a57cc55';
const ADMIN_STORAGE_BYTES = 10 * 1024 * 1024 * 1024;

/**
 * Bootstraps the `admin` user on first boot for self-hosted deployments.
 *
 * If no admin exists, creates one with a random 8-char hex password, places
 * them in the admin group, and stashes the plaintext under
 * `metadata.tmp_password` so we can detect on later boots whether the operator
 * has rotated it yet.
 *
 * Each boot where the current password hash still matches the stashed
 * plaintext, the credentials are re-printed to stdout (CI scrapes this line to
 * extract the default password). Once rotation is detected the stash is deleted
 * so the plaintext isn't retained longer than needed.
 */
export class DefaultUserService extends PuterService {
    override async onServerStart(): Promise<void> {
        // Dev convenience: grant the bootstrap `admin` user unlimited metering.
        // Gated to env === 'dev' so prod deployments never get a free-usage
        // actor. Registering the policy makes its `'unlimited'` id resolvable
        // (extraPolicies is always in the available set); the resolver returns
        // null for everyone else, so all other users keep their normal tier.
        if (this.config.env === 'dev') {
            this.services.metering.registerPolicy(LOCAL_UNLIMITED_USER);
            this.services.metering.registerSubscriptionResolver((actor) =>
                actor.user?.username === USERNAME
                    ? UNLIMITED_SUBSCRIPTION
                    : null,
            );
        }

        if (this.config.no_default_user) return;
        let user = await this.stores.user.getByUsername(USERNAME);
        let tmpPassword: string;

        if (!user) {
            // 16 bytes (128 bits) — the old 4 bytes was only 32 bits,
            // brute-forceable if the box is reachable before the admin
            // rotates the printed bootstrap password.
            tmpPassword = crypto.randomBytes(16).toString('hex');
            user = await this.#createAdminUser(tmpPassword);
        } else {
            const metadata = (user.metadata ?? {}) as Record<string, unknown>;
            const stashed = metadata.tmp_password;
            if (typeof stashed !== 'string' || stashed === '') return;
            tmpPassword = stashed;
        }

        if (!user.password) return;
        const isDefault = await bcrypt.compare(
            tmpPassword,
            String(user.password),
        );
        if (!isDefault) {
            // Password was rotated — stop retaining the plaintext stash.
            await this.stores.user.updateMetadata(user.id, {
                tmp_password: null,
            });
            return;
        }

        this.#printCredentials(tmpPassword);
    }

    async #createAdminUser(tmpPassword: string): Promise<UserRow> {
        const passwordHash = await bcrypt.hash(tmpPassword, 8);

        const created = await provisionUser(
            {
                db: this.clients.db,
                userStore: this.stores.user,
                groupStore: this.stores.group,
            },
            {
                username: USERNAME,
                uuid: uuidv4(),
                password: passwordHash,
                email: null,
                free_storage: ADMIN_STORAGE_BYTES,
                requires_email_confirmation: false,
            },
            ADMIN_GROUP_UID,
        );

        await this.stores.user.updateMetadata(created.id, {
            tmp_password: tmpPassword,
        });
        return (await this.stores.user.getById(created.id)) ?? created;
    }

    #printCredentials(tmpPassword: string): void {
        console.log(`password for admin is: ${tmpPassword}`);
        console.log(
            '\n************************************************************',
        );
        console.log('* Your default login credentials are:');
        console.log('* Username: admin');
        console.log(`* Password: ${tmpPassword}`);
        console.log('* (change the password to remove this message)');
        console.log(
            '************************************************************\n',
        );
    }
}