Song Library API

song library is a Go-based RESTful API for managing a song library. It allows you to store, retrieve, create, update, and delete song information, including lyrics, group details, and release dates.

Features

• Retrieve Song Lyrics: Fetch song lyrics based on various filters (song ID, group name, song name, pagination).
• Browse Song Library: Get a list of songs in the library with filtering capabilities (group, song, release date).
• Create New Songs: Add new songs to the library with details like group name and song name.
• Update Existing Songs: Modify details of existing songs, including group, song name, release date, and external links.
• Delete Songs: Remove songs from the library.
• External API Integration: Integrates with an external API to fetch initial song information.
• Database Persistence: Uses PostgreSQL as the backend database for storing song data.
• RESTful API: Follows REST principles for a clear and consistent API design.
• Logging: Includes basic logs to debug application.

Technologies Used

• Go: Programming language.
• net/http: Go's standard library for HTTP.
• encoding/json: Go's standard library for JSON encoding/decoding.
• pgx: PostgreSQL driver for Go.
• PostgreSQL: Database.
• golang-migrate: Database migration tool.

API Endpoints

Song Lyrics

• GET /api/v1/library/songs?song_id={song_id}
  • Retrieves the lyrics for a specific song by ID.
  • Example: /api/v1/library/songs?song_id=123
• GET /api/v1/library/songs?group={group}&song={song}&page={page}&limit={limit}
  • Retrieves song lyrics based on group and song name, with pagination.
  • group: Name of the music group (e.g., "The Beatles").
  • song: Name of the song (e.g., "Hey Jude").
  • page: Page number to retrieve.
  • limit: Limit of results on page.
  • Example: /api/v1/library/songs?group=The%20Beatles&song=Hey%20Jude&page=1&limit=10
• Error Handling:
  • Returns 400 Bad Request if required parameters (song_id or both group and song) are missing.
  • Returns 404 Not Found if the song is not found.
  • Returns 500 Internal Server Error if there is an issue encoding the response.

Song Management

• POST /api/v1/library/songs

  • Creates a new song.
  • Request Body (JSON):

    {
      "group": "New Group",
      "song": "New Song"
    }

  • Response:
    • 201 Created on success, with a message indicating successful creation.
    • 500 Internal Server Error if there is an error while song creation.
    • 400 Bad Request if request body is not valid.

• PUT /api/v1/library/songs

  • Updates an existing song.
  • Request Body (JSON):

    {
      "id": "123",
      "group": "Updated Group",
      "song": "Updated Song",
      "release_date": "2023-10-27",
      "link": "https://example.com/updated-link"
    }

    • release_date must be in YYYY-MM-DD format.
  • Response:
    • 200 OK on success, with a message indicating successful update.
    • 500 Internal Server Error if there is an error while song updating.
    • 400 Bad Request if request body is not valid.

• DELETE /api/v1/library/songs?song_id={song_id}

  • Deletes an existing song.
  • song_id: ID of song to delete.
  • Example: /api/v1/library/songs?song_id=123
  • Response:
    • 200 OK on success, with a message indicating successful deletion.
    • 500 Internal Server Error if there is an error while song deleting.
    • 400 Bad Request if song_id is not provided.

Library Data

• GET /api/v1/library?group={group}&song={song}&release_date={release_date}&limit={limit}&offset={offset}
  • Retrieves a list of songs from the library based on various filters.
  • group: Filter by group name.
  • song: Filter by song name.
  • release_date: Filter by release date.
  • limit: Limit of results on page.
  • offset: Offset of the results.
  • Example: /api/v1/library?group=The%20Beatles&limit=20&offset=10
• Error Handling:
  • Returns 404 Not Found if library data is not found.
  • Returns 500 Internal Server Error if there is an issue encoding the response.

Getting Started

Prerequisites

• Go: Make sure you have Go installed on your system.
• PostgreSQL: You need a running PostgreSQL database instance.
• External API: There is an External API client, you should implement it.

Configuration

The application is configured using environment variables, stored in a .env file in the root directory of the project.

1. Create .env: Create a new file named .env in the project's root directory.

2. Populate .env: Add the following environment variables to your .env file, adjusting the values as needed:

   DB_NAME=mydb
   DB_HOST=localhost
   DB_PORT=5432
   DB_USER=user
   DB_PASSWORD=secret
   DB_SSLMODE=disable
   MIGRATIONS_PATH=C:/song-library # You should change it to correct path.
   SERVER_PORT=8080
   API_NAME=example_api
   API_URL=https://api.example.com
   ENABLE_DEBUG=true

   • DB_NAME: The name of your PostgreSQL database.
   • DB_HOST: The hostname or IP address of your PostgreSQL server.
   • DB_PORT: The port your PostgreSQL server is listening on (default: 5432).
   • DB_USER: The username for connecting to your PostgreSQL database.
   • DB_PASSWORD: The password for the database user.
   • DB_SSLMODE: The SSL mode for the database connection (e.g., disable, require).
   • MIGRATIONS_PATH: Path to project root directory.
   • SERVER_PORT: The port the API server will run on (default: 8080).
   • API_NAME: Name of your API, can be any.
   • API_URL: URL to you API, can be any.
   • ENABLE_DEBUG: Enable debug logs if true.

Installation

1. Clone the repository:

   git clone <repository-url>
   cd sing-lib

2. Install dependencies:

   go mod download

3. Run the application:

   go run cmd/song-library/main.go