package main

import (
	"bytes"
	"errors"
	"fmt"
	"io"
	"log"
	"mime/multipart"
	"net/http"
	"os"
	"path/filepath"
	"regexp"
	"strconv"
)

/*
Demonstration of using the tusd as a client to send file uploads
with just multiparts being written to the server (acting as a proxy between client and s3)
*/

func main() {
	SendPostRequest("http://localhost:8080/files/upload/", "test.txt", "txt")
}

func SendPostRequest(url string, filename string, filetype string) (string, error) {
	file, err := os.Open(filename)

	if err != nil {
		log.Fatal(err)
	}
	defer file.Close()

	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	part, err := writer.CreateFormFile(filetype, filepath.Base(file.Name()))

	if err != nil {
		log.Fatal(err)
	}

	io.Copy(part, file)
	writer.Close()
	request, err := http.NewRequest("POST", url, body)

	if err != nil {
		log.Fatal(err)
	}

	fileStats, err := file.Stat()
	if err != nil {
		// Could not obtain stat, handle error
	}
	fileSize := strconv.FormatInt(fileStats.Size(), 10)
	request.Header.Add("Tus-Resumable", "1.0.0")
	request.Header.Add("Upload-Offset", "0")
	request.Header.Add("Content-Length", fileSize)
	request.Header.Add("Upload-Length", fileSize)
	request.Header.Add("Content-Type", writer.FormDataContentType())
	client := &http.Client{}

	response, err := client.Do(request)

	if err != nil {
		log.Fatal(err)
	}
	defer response.Body.Close()

	if response.StatusCode != 201 {
		fmt.Println("There was an error with the request ", response.StatusCode)
	} else {
		r := regexp.MustCompile(`files\/upload\/(.*?)\+`)
		subStrings := r.FindStringSubmatch(response.Header["Location"][0])
		// [0] is the full string
		storedFileName := subStrings[1]
		fmt.Println("stored File Name "+storedFileName, " status code: ", response.StatusCode)
		return storedFileName, nil
	}

	return "", errors.New("The file upload failed")

}