public-ip-tracker/tracker/config/config.go

package config

import (
	"encoding/json"
	"fmt"
	"os"
	"time"
)

type TelegramConfig struct {
	ChannelID int64  `json:"channel_id"`
	Token     string `json:"token"`
}

type Config struct {
	Telegram         *TelegramConfig
	PollingFrequency time.Duration
}

type jsonConfig struct {
	Telegram         *TelegramConfig `json:"telegram"`
	PollingFrequency int64           `json:"polling_frequency"`
}

func New(filepath string) (*Config, error) {
	content, err := os.ReadFile(filepath)
	if err != nil {
		return nil, fmt.Errorf("failed to read config file %q: %w", filepath, err)
	}
	var jsonConf jsonConfig
	if err := json.Unmarshal(content, &jsonConf); err != nil {
		return nil, fmt.Errorf("failed to parse config file: %w", err)
	}
	return &Config{
		Telegram:         jsonConf.Telegram,
		PollingFrequency: time.Duration(jsonConf.PollingFrequency) * time.Second,
	}, nil
}