import type { RconFailure } from '$ui/stores/servers.js';

export interface DecodedRconError {
    reason: RconFailure;
    detail: string;
}

const KNOWN: RconFailure[] = [
    'no-config',
    'no-port',
    'send-error',
    'timeout',
    'bad-reply',
    'no-players'
];

/**
 * Decode the "<reason>:<detail>" string the worker persists into
 * `servers.last_error`. Returns null for empty/legacy strings so the UI can
 * fall back to a generic message.
 */
export function decodeRconError(raw: string | null | undefined): DecodedRconError | null {
    if (!raw) return null;
    const idx = raw.indexOf(':');
    if (idx <= 0) return null;
    const reason = raw.slice(0, idx);
    if (!KNOWN.includes(reason as RconFailure)) return null;
    return { reason: reason as RconFailure, detail: raw.slice(idx + 1).trim() };
}

/**
 * Human-facing hint about how to fix each RCON failure. Kept short — the
 * detail already carries the specifics (host, port, byte counts, etc.).
 */
export function rconFixHint(reason: RconFailure): string {
    switch (reason) {
        case 'no-config':
            return 'Set RCON_PASSWORD in the container env and restart.';
        case 'no-port':
            return 'Check the host agent and the game port assigned to this server.';
        case 'send-error':
            return 'DNS or route problem — check the RCON host is reachable from this container.';
        case 'timeout':
            return 'Plutonium is not replying on the resolved UDP port. Verify the server is running and the port matches.';
        case 'bad-reply':
            return 'Something is listening but not speaking Plutonium RCON. Check the port and password.';
        case 'no-players':
            return 'Reply parsed but no player table was found — likely a server-side dialect mismatch.';
    }
}