SongLibrary

SongLibrary is a RESTful service for managing a music library. It enriches song data using an external API (you can test it by running this code) and stores it in a PostgreSQL database. Features include filtering, pagination, verse extraction, and Swagger documentation.

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Features

• Retrieve a list of songs with filtering by all fields and pagination
• Get song lyrics split into paginated verses
• Add new songs via JSON request (with enrichment from an external API)
• Update and delete existing songs
• Automatic database migration on startup
• Detailed logging with debug and info levels
• Swagger-generated API documentation
• Docker support for easy deployment
• Makefile for simplified development commands

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Tech Stack

• Go (Gin, GORM)
• PostgreSQL
• Docker / Docker Compose
• Swagger (Swaggo)
• Logrus (for logging)

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Docker Setup

1. Environment Variables

Create a .env file in the project root and configure it like .env.example and external API URL here.

### 2. Build & Run via Makefile

```bash
# Build Docker images
make build

# Run containers (app + postgres)
make run

# Stop containers
make stop

# Clean containers, images, volumes
make clean

App will be available at: http://localhost:8080
Swagger UI: http://localhost:8080/swagger/index.html

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Local Development (No Docker)

1. Install dependencies

go mod tidy

2. Create .env and set DB credentials

3. Run the app

go run cmd/main.go

4. Generate Swagger docs

swag init --generalInfo cmd/main.go

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API Endpoints

GET /songs

Retrieve songs with filtering and pagination
Query Parameters:

• id — Song ID
• group — Group name
• song — Song name
• releaseDate — Release date (2006-01-02, 2006.01.02, or RFC3339)
• text — Text fragment
• page — Page number (default: 1)
• limit — Items per page (default: 10)

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GET /songs/{id}/verses

Retrieve song lyrics, split by paragraphs (double newline \n\n can change here)
Query:

• page — Page number (default: 1)
• limit — Verses per page (default: 3)

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POST /songs

Add a song using external API enrichment
Body:

{
  "group": "Muse",
  "song": "Supermassive Black Hole"
}

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PUT /songs/{id}

Update a song by ID
Body:

{
  "group_name": "Muse",
  "song_name": "Starlight",
  "release_date": "2006-07-16",
  "text": "Ooh baby, don't you know I suffer...",
  "link": "https://youtube.com/example"
}

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DELETE /songs/{id}

Delete a song by ID

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Database Migration

The app uses gorm.AutoMigrate() to automatically create the required table.
Schema (simplified):

CREATE TABLE IF NOT EXISTS songs
(
    id           SERIAL PRIMARY KEY,
    group_name   TEXT NOT NULL,
    song_name    TEXT NOT NULL,
    release_date DATE NOT NULL,
    text         TEXT NOT NULL,
    link         TEXT NOT NULL,
    created_at   TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at   TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE UNIQUE INDEX IF NOT EXISTS unique_song ON songs (group_name, song_name);

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Logs

• DEBUG — Incoming requests, parameters, external API calls
• INFO — Successful actions (song added/updated/deleted)
• ERROR — Failures in DB operations or external API responses

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Swagger Docs

swag init

Accessible at: http://localhost:8080/swagger/index.html

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Clean Up

To remove all Docker containers, images, and volumes:

make clean

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