package main

import (
	"fmt"
	"io"
	"log"
	"net/http"
	"os"

	jsoniter "github.com/json-iterator/go"
)

func readJSONFile(filename string, dst any) error {
	log.Printf("Reading %s\n", filename)
	file, err := os.Open(filename)
	if err != nil {
		return err
	}
	defer file.Close()

	return jsoniter.ConfigFastest.NewDecoder(file).Decode(dst)
}

func downloadFile(url, filename string) error {
	log.Printf("%s not found, downloading from %s \n", filename, url)
	response, err := http.Get(url)
	if err != nil {
		return err
	}
	defer response.Body.Close()

	if response.StatusCode != http.StatusOK {
		return fmt.Errorf("request failed with status code: %d", response.StatusCode)
	}

	f, err := os.Create(filename)
	if err != nil {
		return err
	}
	defer f.Close()

	_, err = io.Copy(f, response.Body)
	return err
}