@@ -1,3 +1,4 @@
 .env
 *.sav
 *.dsv
+.vscode

@@ -1,15 +0,0 @@
-{
-    // Use IntelliSense to learn about possible attributes.
-    // Hover to view descriptions of existing attributes.
-    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
-    "version": "0.2.0",
-    "configurations": [
-        {
-            "name": "Launch Package",
-            "type": "go",
-            "request": "launch",
-            "mode": "auto",
-            "program": "${fileDirname}"
-        }
-    ]
-}

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"io"
+	"net/http"
+	"path/filepath"
+	"strconv"
+)
+
+type ConverterFunction func([]byte) []byte
+
+const (
+	MB                 = 1 << 20
+	DefaultMaxFileSize = 2
+	TrimBytes          = 122
+	AdditionalBytesHex = "7C3C2D2D536E69702061626F7665206865726520746F2063726561746520612072617720736176206279206578636C7564696E672074686973204465536D754D4520736176656461746120666F6F7465723A0000010000000100030000000200000000000100000000007C2D4445534D554D4520534156452D7C"
+)
+
+var (
+	MaxFileSize        int64
+	AdditionalBytes    []byte
+	ConverterFunctions = map[string]ConverterFunction{
+		".dsv": DsvToSav,
+		".sav": SavToDsv,
+	}
+)
+
+func DsvToSav(input []byte) []byte {
+	return input[:len(input)-TrimBytes]
+}
+
+func SavToDsv(input []byte) []byte {
+	return append(input, AdditionalBytes...)
+}
+
+func postHandler(w http.ResponseWriter, r *http.Request) {
+	// Parse the multipart form data
+	err := r.ParseMultipartForm(MaxFileSize)
+	if err != nil {
+		http.Error(w, "Error parsing form", http.StatusBadRequest)
+		return
+	}
+
+	r.Body = http.MaxBytesReader(w, r.Body, MaxFileSize)
+
+	// Get the file from the request
+	file, h, err := r.FormFile("file")
+	if err != nil {
+		http.Error(w, "Error retrieving file from form data", http.StatusBadRequest)
+		return
+	}
+	defer file.Close()
+
+	// Check file size
+	if h.Size > MaxFileSize {
+		http.Error(w, "File size exceeds 1MB", http.StatusBadRequest)
+		return
+	}
+
+	var outputContent []byte
+
+	// Check file extension
+	fileExt := filepath.Ext(h.Filename)
+	converterFunction, exists := ConverterFunctions[fileExt]
+	if !exists {
+		http.Error(w, "Invalid file format, only .dsv and .sav files are allowed", http.StatusBadRequest)
+		return
+	}
+
+	content, err := io.ReadAll(file)
+	if err != nil {
+		http.Error(w, "Error reading file content", http.StatusInternalServerError)
+		return
+	}
+	outputContent = converterFunction(content)
+
+	w.Header().Set("Content-Length", strconv.Itoa(len(outputContent)))
+	w.Header().Set("Content-Type", "application/octet-stream")
+	w.WriteHeader(http.StatusOK)
+	w.Write(outputContent)
+}

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"bytes"
+	"embed"
+	"net/http"
+	"text/template"
+)
+
+const templatesDirectory = "templates/"
+
+var (
+	//go:embed templates/index.html
+	templates     embed.FS
+	indexTemplate = template.Must(template.ParseFS(templates, templatesDirectory+"index.html"))
+)
+
+func getHandler(w http.ResponseWriter) {
+	buf := &bytes.Buffer{}
+	err := indexTemplate.Execute(buf, nil)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	buf.WriteTo(w)
+}

@@ -2,32 +2,15 @@ package main
 
 import (
 	"encoding/hex"
-	"io"
 	"net/http"
 	"os"
-	"path/filepath"
 	"strconv"
 
 	"github.com/joho/godotenv"
 )
 
-type ConverterFunction func([]byte) []byte
-
 const (
-	MB                 = 1 << 20
-	DefaultMaxFileSize = 2
-	DefaultPort        = "1111"
-	TrimBytes          = 122
-	AdditionalBytesHex = "7C3C2D2D536E69702061626F7665206865726520746F2063726561746520612072617720736176206279206578636C7564696E672074686973204465536D754D4520736176656461746120666F6F7465723A0000010000000100030000000200000000000100000000007C2D4445534D554D4520534156452D7C"
-)
-
-var (
-	MaxFileSize        int64
-	AdditionalBytes    []byte
-	ConverterFunctions = map[string]ConverterFunction{
-		".dsv": DsvToSav,
-		".sav": SavToDsv,
-	}
+	DefaultPort = "1111"
 )
 
 func main() {
@@ -51,62 +34,19 @@ MaxFileSize *= MB
 
 	AdditionalBytes, _ = hex.DecodeString(AdditionalBytesHex)
 
-	http.HandleFunc("/", uploadHandler)
+	http.HandleFunc("/", mainHandler)
 	println("Listening on port " + port)
 	http.ListenAndServe(":"+port, nil)
 }
 
-func DsvToSav(input []byte) []byte {
-	return input[:len(input)-TrimBytes]
-}
-
-func SavToDsv(input []byte) []byte {
-	return append(input, AdditionalBytes...)
-}
-
-func uploadHandler(w http.ResponseWriter, r *http.Request) {
-	// Parse the multipart form data
-	err := r.ParseMultipartForm(MaxFileSize)
-	if err != nil {
-		http.Error(w, "Error parsing form", http.StatusBadRequest)
-		return
-	}
-
-	r.Body = http.MaxBytesReader(w, r.Body, MaxFileSize)
-
-	// Get the file from the request
-	file, h, err := r.FormFile("file")
-	if err != nil {
-		http.Error(w, "Error retrieving file from form data", http.StatusBadRequest)
-		return
-	}
-	defer file.Close()
-
-	// Check file size
-	if h.Size > MaxFileSize {
-		http.Error(w, "File size exceeds 1MB", http.StatusBadRequest)
-		return
-	}
-
-	var outputContent []byte
-
-	// Check file extension
-	fileExt := filepath.Ext(h.Filename)
-	converterFunction, exists := ConverterFunctions[fileExt]
-	if !exists {
-		http.Error(w, "Invalid file format, only .dsv and .sav files are allowed", http.StatusBadRequest)
-		return
-	}
-
-	content, err := io.ReadAll(file)
-	if err != nil {
-		http.Error(w, "Error reading file content", http.StatusInternalServerError)
+func mainHandler(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case http.MethodGet:
+		getHandler(w)
 		return
+	case http.MethodPost:
+		postHandler(w, r)
+	default:
+		http.Error(w, "Method not supported", http.StatusBadRequest)
 	}
-	outputContent = converterFunction(content)
-
-	w.Header().Set("Content-Length", strconv.Itoa(len(outputContent)))
-	w.Header().Set("Content-Type", "application/octet-stream")
-	w.WriteHeader(http.StatusOK)
-	w.Write(outputContent)
 }

@@ -0,0 +1,67 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta http-equiv="X-UA-Compatible" content="ie=edge">
+    <title>NDS Converter</title>
+    <style>
+        body, a {
+            background-color: #212529;
+            color: #dee2e6;
+            font-family: sans-serif;
+        }
+        hr {
+            width: 400px;
+            text-align: left;
+            margin-left: 0px;
+            margin-top: 20px;
+        }
+    </style>
+</head>
+
+<body>
+    <h2>NDS Converter</h2>
+    <p>Please, select one or more <code>.sav</code> or <code>.dsv</code> files.</p>
+    <input type="file" accept=".dsv,.sav" multiple onchange="convertFiles(this)">
+    <hr>
+    <p><a href="https://github.com/BiRabittoh/nds-converter">Source code</a></p>
+
+    <script>
+        async function convertFiles(element) {
+            for (f of element.files) {
+                await convert(f);
+            }
+        }
+
+        async function convert(file) {
+            const formData = new FormData();
+            formData.append('file', file);
+
+            const response = await fetch('/', {
+                method: 'POST',
+                body: formData,
+            });
+
+            if (!response.ok) {
+                alert(`Error ${response.status}: ${await response.text()}`);
+                return;
+            }
+
+            const newExtension = file.name.endsWith('.dsv') ? '.sav' : '.dsv';
+
+            const blob = await response.blob();
+
+            const link = document.createElement('a');
+            link.href = window.URL.createObjectURL(blob);
+            link.download = file.name.replace(/\.[^.]+$/, '') + newExtension;
+
+            document.body.appendChild(link);
+            link.click();
+            document.body.removeChild(link);
+        }
+    </script>
+</body>
+
+</html>