Управление треками и поиск

Relevant source files

The following files were used as context for generating this wiki page:

• internal/features/tracks/repository/postgres/track_repository.go
• internal/features/tracks/transport/http/transport.go
• internal/features/tracks/service/play.go
• internal/features/tracks/transport/http/search_tracks.go
• internal/features/tracks/transport/http/list_tracks.go
• migrations/001_init.up.sql

The "Управление треками и поиск" (Track Management and Search) module is a core component of the music service responsible for managing the music catalog, handling track playback logic, and providing search capabilities. It encompasses administrative functions for creating and updating tracks, as well as user-facing features such as browsing the catalog and searching for specific content.

The system is built using a layered architecture, separating concerns between the HTTP transport layer, the business logic (service) layer, and the data persistence layer (PostgreSQL and Redis). It also implements subscription-based access control, specifically enforcing daily listening limits for users with "FREE" accounts.

Архитектура и структура данных

Модель данных (Entity Relationship)

The track entity is central to the database schema, maintaining relationships with artists, albums, and genres.

Основные поля трека

Field	Type	Description
id	int64	Unique identifier (Primary Key)
title	string	The title of the track
artist_id	int64	Foreign key to the artists table
album_id	int64	Foreign key to the albums table (nullable)
genre_id	int64	Foreign key to the genres table (nullable)
duration_seconds	int	Length of the track in seconds
file_url	string	URL to the audio file
is_active	bool	Status flag for soft deletion/visibility

Sources: internal/features/tracks/transport/http/transport.go:27-35, migrations/001_init.up.sql:43-53

Бизнес-логика прослушивания (Playback)

The system manages track playback through the Play method in the service layer. This method implements a critical business rule: users with a FREE subscription are limited to a specific number of plays per day.

Процесс прослушивания

1. Validation: The system checks if the track exists and is marked as is_active.
2. Limit Check: For FREE users, it queries Redis using a key formatted as user:{id}:daily_play_count:{date}.
3. Incrementing: if the limit is not exceeded, the count in Redis is incremented using a transaction (atomic pipeline) with a 24-hour expiration.
4. Persistence: The event is recorded in the listening_history table in PostgreSQL.

Поиск и листинг (Search and Discovery)

Поиск треков

The search functionality uses the ILIKE operator in PostgreSQL to perform case-insensitive pattern matching across multiple fields: track title, artist name, album title, and genre name.

• Endpoint: GET /api/v1/tracks/search?query=...
• Logic: Returns tracks where the query string matches any of the catalog details.

Sources: internal/features/tracks/repository/postgres/track_repository.go:124-144, internal/features/tracks/transport/http/search_tracks.go:31-48

Пагинация списка

The general list of tracks supports pagination through limit and page query parameters. By default, it returns 20 tracks per page.

Parameter	Type	Default	Description
limit	int	20	Number of tracks per request
page	int	1	Current page number

Sources: internal/features/tracks/transport/http/list_tracks.go:34-54

Административное управление

The module provides restricted endpoints for managing the music catalog, requiring the ADMIN role.

API Эндпоинты управления

Method	Path	Description
POST	/admin/tracks	Create a new music track
PUT	/admin/tracks/{id}	Update existing track details
DELETE	/admin/tracks/{id}	Soft delete a track (sets is_active = false)

Sources: internal/features/tracks/transport/http/transport.go:70-86

Реализация Soft Delete

Instead of removing records from the database, the system uses a SoftDelete method. This updates the is_active flag to FALSE, ensuring that historical data (like listening_history) remains valid while the track becomes unavailable for search or playback.

func (r *TrackRepository) SoftDelete(ctx context.Context, id int64) error {
	query := `UPDATE tracks SET is_active = FALSE WHERE id = $1`
	res, err := r.db.ExecContext(ctx, query, id)
    // ... validation logic
	return nil
}

Sources: internal/features/tracks/repository/postgres/track_repository.go:66-72

Заключение

Система управления треками обеспечивает гибкий механизм работы с музыкальным каталогом, совмещая в себе функции поиска, администрирования и строгого контроля доступа. Использование Redis для отслеживания дневных лимитов позволяет эффективно масштабировать бизнес-ограничения для бесплатных аккаунтов, не создавая избыточной нагрузки на основную базу данных PostgreSQL.