/*
 * Veskslop daemon — auth state for the web UI.
 *
 * Owns at most one QR login session. The terminal tool and the web UI share
 * the session class. The token file stays the single credential store.
 */

import { existsSync } from "node:fs";

import { isTerminalQrState, QrLoginSession, type QrLoginState, type QrLoginUpdate } from "./qr-session.js";

export interface AuthSessionSnapshot {
    state: QrLoginState;
    url?: string;
    user?: object;
    error?: string;
    captcha?: object;
}

export interface AuthStatus {
    tokenFile: string;
    hasToken: boolean;
    session: AuthSessionSnapshot | null;
}

export class AuthService {
    private session?: QrLoginSession;
    private snapshot: AuthSessionSnapshot | null = null;
    private freshLogin = false;

    constructor(
        private readonly tokenFile: string,
        private readonly onUpdate?: (update: QrLoginUpdate) => void
    ) {}

    status(): AuthStatus {
        return {
            tokenFile: this.tokenFile,
            hasToken: existsSync(this.tokenFile),
            session: this.snapshot ? structuredClone(this.snapshot) : null
        };
    }

    startQr(): AuthStatus {
        if (this.session && !isTerminalQrState(this.session.state)) return this.status();

        this.snapshot = { state: "connecting" };
        this.session = new QrLoginSession({
            tokenFile: this.tokenFile,
            debug: process.env.DEBUG === "1",
            onUpdate: update => {
                this.snapshot = { ...update };
                if (update.state === "finished") this.freshLogin = true;
                this.onUpdate?.(update);
            }
        });
        this.session.start();

        return this.status();
    }

    cancelQr(): AuthStatus {
        this.session?.cancel();
        return this.status();
    }

    submitCaptcha(key: string): boolean {
        return this.session?.submitCaptcha(key) ?? false;
    }

    /** True once after a successful login. Used to force the new token on start. */
    consumeFreshLogin(): boolean {
        const value = this.freshLogin;
        this.freshLogin = false;
        return value;
    }

    clearFreshLogin(): void {
        this.freshLogin = false;
    }
}