@@ -0,0 +1,2 @@
+PORT=1111
+MAX_SIZE_MB=2

@@ -0,0 +1,3 @@
+.env
+*.sav
+*.dsv

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+{
+    // 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 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Marco Andronaco
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

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+# nds-converter
+
+## What is it?
+A lightweight API-first tool to convert NDS save files (`.sav`) to and from the DeSmuME format (`.dsv`).
+
+## How do I use it?
+First, you need a save file, either of the two formats will work.
+Then, you can just use `curl`:
+
+```
+curl localhost:1111 -F file=@savefile.sav > savefile.dsv
+```
+
+The conversion works both ways.
+```
+curl localhost:1111 -F file=@savefile.dsv > savefile.sav
+```

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+module github.com/BiRabittoh/nds-converter
+
+go 1.22.1
+
+require github.com/joho/godotenv v1.5.1

@@ -0,0 +1,2 @@
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=

@@ -0,0 +1,112 @@
+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,
+	}
+)
+
+func main() {
+	// Load the .env file
+	err := godotenv.Load()
+	if err != nil {
+		println("Could not load .env file")
+	}
+
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = DefaultPort
+	}
+
+	fileSizeString := os.Getenv("MAX_SIZE_MB")
+	MaxFileSize, err = strconv.ParseInt(fileSizeString, 10, 64)
+	if err != nil {
+		MaxFileSize = DefaultMaxFileSize
+	}
+	MaxFileSize *= MB
+
+	AdditionalBytes, _ = hex.DecodeString(AdditionalBytesHex)
+
+	http.HandleFunc("/", uploadHandler)
+	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)
+		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)
+}