package main

import (
	"fmt"
	"html/template"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"strings"
)

func indexHandler(w http.ResponseWriter, r *http.Request) {
	tmpl, _ := template.New("index.html").ParseFiles("index.html")

	server, _ := ioutil.ReadFile("main.go")

	tmpl.Execute(w, string(server))
}

func staticHandler(w http.ResponseWriter, r *http.Request) {
	r.ParseForm()

	filepath := r.Form.Get("file")
	filepath = fmt.Sprintf("static/%v", filepath)

	if len(filepath) == 0 {
		_, err := w.Write([]byte("file parameter is required"))
		if err != nil {
			log.Println("Can't write response")
		}
		return
	}

	if strings.Contains(filepath, "..") {
		filepath = strings.ReplaceAll(filepath, "..", ".")
	}

	file, _ := ioutil.ReadFile(filepath)

	w.Write(file)
}

func main() {
	http.HandleFunc("/", indexHandler)
	http.HandleFunc("/static/", staticHandler)

	addr, _ := os.LookupEnv("ADDR")
	log.Fatal(http.ListenAndServe(addr, nil))
}