/**
 * 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();
}