/**
 * config.js — Connection configuration for The Matrix.
 *
 * Override at deploy time via URL query params:
 *   ?ws=ws://tower:8080/ws/world-state   — WebSocket endpoint
 *   ?token=my-secret                      — Auth token (Phase 1 shared secret)
 *   ?mock=true                            — Force mock mode (no real WS)
 *
 * Or via Vite env vars:
 *   VITE_WS_URL    — WebSocket endpoint
 *   VITE_WS_TOKEN  — Auth token
 *   VITE_MOCK_MODE — 'true' to force mock mode
 *
 * Priority: URL params > env vars > defaults.
 *
 * Resolves Issue #7 — js/config.js
 * Resolves Issue #11 — WS authentication strategy (Phase 1: shared secret)
 */

const params = new URLSearchParams(window.location.search);

function param(name, envKey, fallback) {
  return params.get(name)
    ?? (import.meta.env[envKey] || null)
    ?? fallback;
}

export const Config = Object.freeze({
  /** WebSocket endpoint. Empty string = no live connection (mock mode). */
  wsUrl: param('ws', 'VITE_WS_URL', ''),

  /** Auth token appended as ?token= query param on WS connect (Issue #11). */
  wsToken: param('token', 'VITE_WS_TOKEN', ''),

  /** Force mock mode even if wsUrl is set. Useful for local dev. */
  mockMode: param('mock', 'VITE_MOCK_MODE', 'false') === 'true',

  /** Reconnection timing */
  reconnectBaseMs: 2000,
  reconnectMaxMs: 30000,

  /** Heartbeat / zombie detection */
  heartbeatIntervalMs: 30000,
  heartbeatTimeoutMs: 5000,

  /**
   * Computed: should we use the real WebSocket client?
   * True when wsUrl is non-empty AND mockMode is false.
   */
  get isLive() {
    return this.wsUrl !== '' && !this.mockMode;
  },

  /**
   * Build the final WS URL with auth token appended as a query param.
   * Returns null if not in live mode.
   *
   * Result: ws://tower:8080/ws/world-state?token=my-secret
   */
  get wsUrlWithAuth() {
    if (!this.isLive) return null;
    const url = new URL(this.wsUrl);
    if (this.wsToken) {
      url.searchParams.set('token', this.wsToken);
    }
    return url.toString();
  },
});