threadule/backend/internal/config/config.go

package config

import (
	"errors"
	"fmt"
	"github.com/pelletier/go-toml/v2"
	"io/fs"
	"os"
)

type web struct {
	Port uint
}

type database struct {
	DSN string
}

type twitter struct {
	ConsumerKey    string
	ConsumerSecret string
}

type Config struct {
	Web      web
	Database database
	Twitter  twitter
}

func writeDefaultConfig(path string) error {
	content, err := toml.Marshal(&Config{
		Web:      web{Port: 8080},
		Database: database{DSN: ""},
		Twitter: twitter{
			ConsumerKey:    "",
			ConsumerSecret: "",
		},
	})
	if err != nil {
		return fmt.Errorf("couldn't generate default config: %w", err)
	}

	err = os.WriteFile(path, content, fs.FileMode(0640))
	if err != nil {
		return err
	}

	return errors.New(fmt.Sprintf("config file not be read; generated empty file in: %s", path))
}

func Read(path string) (*Config, error) {
	content, err := os.ReadFile(path)
	if err != nil {
		return nil, writeDefaultConfig(path)
	}

	var config Config
	err = toml.Unmarshal(content, &config)
	if err != nil {
		return nil, err
	}

	return &config, nil
}