main.go

package main

import (
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"
	"runtime"
	"text/template"
)

//Schedule for struct
type Schedule struct {
	Input  [][]int
	Result [][]int
	Avwt   float64
	Avtat  float64
}

// main program
func main() {
	runtime.GOMAXPROCS(2)

	http.HandleFunc("/", routeIndexGet)
	http.Handle("/static/",
		http.StripPrefix("/static/",
			http.FileServer(http.Dir("assets"))))

	fmt.Println("server started at localhost:9000")
	http.ListenAndServe(":9000", nil)

}

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

	switch r.Method {
	case "POST":
		var tmpl = template.Must(template.New("form").ParseFiles("index.html"))

		if err := r.ParseMultipartForm(1024); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		uploadedFile, handler, err := r.FormFile("file")
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		defer uploadedFile.Close()

		dir, err := os.Getwd()
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		filename := handler.Filename

		fileLocation := filepath.Join(dir, "assets/files", filename)
		targetFile, err := os.OpenFile(fileLocation, os.O_WRONLY|os.O_CREATE, 0666)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		defer targetFile.Close()

		if _, err := io.Copy(targetFile, uploadedFile); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		filelocation := "assets/files/" + filename
		in, initial := newTaskFromFile(filelocation)
		quicksort(in)
		result, avwt, avtat := schedulingProcess(in)
		data := Schedule{
			Input:  initial,
			Result: result,
			Avwt:   avwt,
			Avtat:  avtat,
		}

		err = tmpl.ExecuteTemplate(w, "form", data)

		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
	case "GET":
		var tmpl = template.Must(template.New("form").ParseFiles("index.html"))
		var err = tmpl.ExecuteTemplate(w, "form", nil)

		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
	default:
		http.Error(w, "", http.StatusBadRequest)
	}
}