/**
 * Smart preloading service for upcoming tracks
 * Automatically queues downloads for the next few tracks in the queue
 *
 * TRACES: UR-004, UR-011 | DR-006, DR-015
 */

import { commands } from "$lib/api/bindings";
import type { CacheConfig } from "$lib/api/bindings";
import { auth } from "$lib/stores/auth";
import { createLogger } from "$lib/utils/logger";

const log = createLogger("Preload");

interface PreloadOptions {
  /** Enable debug logging */
  debug?: boolean;
  /** Override user ID (defaults to current session user) */
  userId?: string;
}

/**
 * Trigger preloading for upcoming tracks in the queue
 * This should be called after playback starts or advances to the next track
 */
export async function preloadUpcomingTracks(options: PreloadOptions = {}): Promise<void> {
  const { debug = false, userId: overrideUserId } = options;

  try {
    // Get current user ID
    const userId = overrideUserId || auth.getUserId();

    if (!userId) {
      if (debug) log.debug("No active user session, skipping preload");
      return;
    }

    if (debug) log.debug("Triggering preload for user:", userId);

    // downloadBasePath is currently unused in the backend
    const result = await commands.playerPreloadUpcoming(userId, "/downloads");

    if (debug) {
      log.debug("Result:", {
        queued: result.queuedCount,
        alreadyDownloaded: result.alreadyDownloaded,
        skipped: result.skipped,
      });
    }

    // Log meaningful results
    if (result.queuedCount > 0) {
      log.debug(`Queued ${result.queuedCount} track(s) for background download`);
    }
  } catch (error) {
    // Fail silently - preloading is a background optimization
    // Don't interrupt the user's playback experience
    log.warn("Failed to preload upcoming tracks:", error);
  }
}

/**
 * Update smart cache configuration
 */
export async function updateCacheConfig(config: CacheConfig): Promise<void> {
  await commands.playerSetCacheConfig(config);
}

/**
 * Get current cache configuration
 */
export async function getCacheConfig(): Promise<CacheConfig> {
  return await commands.playerGetCacheConfig();
}