From fba51d78b815b1fc50c23b5941bcdb141ddb57ab Mon Sep 17 00:00:00 2001
From: Kr4ight <dhecxba@gmail.com>
Date: Mon, 6 Apr 2026 21:13:02 +0200
Subject: [PATCH] Working Instance Sync

---
 src-tauri/src/features/instance_sync.rs | 73 +++++++++++++++++++++++--
 src-tauri/src/features/mod.rs           | 15 +++++
 src-tauri/src/lib.rs                    |  8 ++-
 3 files changed, 90 insertions(+), 6 deletions(-)

diff --git a/src-tauri/src/features/instance_sync.rs b/src-tauri/src/features/instance_sync.rs
index f597f98..1949e78 100644
--- a/src-tauri/src/features/instance_sync.rs
+++ b/src-tauri/src/features/instance_sync.rs
@@ -1,9 +1,9 @@
-use std::collections::HashMap;
+use std::{collections::HashMap, fs, path::PathBuf};
 
 use lyceris::auth::microsoft::MinecraftAccount;
 use tauri::State;
 
-use crate::{features::Feature, GameVersion, SharedState};
+use crate::{features::Feature, launcher::launcher_dir, GameVersion, SharedState};
 
 pub struct InstanceSync {}
 
@@ -20,7 +20,7 @@ impl Feature for InstanceSync {
         version: &GameVersion,
         account: &MinecraftAccount,
     ) -> super::FeatureResult {
-        println!("Launching {} for {}", version.id, account.username);
+        sync_to_instance(version).map_err(|e| e.to_string())?;
 
         Ok(())
     }
@@ -31,12 +31,70 @@ impl Feature for InstanceSync {
         version: &GameVersion,
         account: &MinecraftAccount,
     ) -> super::FeatureResult {
-        println!("Game launched!");
+        sync_back_from_instance(version).map_err(|e| e.to_string())?;
 
         Ok(())
     }
 }
 
+fn sync_to_instance(version: &GameVersion) -> std::io::Result<()> {
+    let global_path = options_path_global();
+    let instance_path = options_path_instance(version);
+
+    if !global_path.exists() {
+        if let Ok(instance_content) = fs::read_to_string(instance_path) {
+            fs::write(global_path, instance_content)?;
+        }
+
+        return Ok(());
+    }
+
+    let global_content = fs::read_to_string(global_path)?;
+
+    // Ensure instance dir exists
+    if let Some(parent) = instance_path.parent() {
+        fs::create_dir_all(parent)?;
+    }
+
+    fs::write(instance_path, global_content)?;
+
+    Ok(())
+}
+
+fn sync_back_from_instance(version: &GameVersion) -> std::io::Result<()> {
+    let global_path = options_path_global();
+    let instance_path = options_path_instance(version);
+
+    let global_content = fs::read_to_string(&global_path)?;
+    let instance_content = fs::read_to_string(&instance_path)?;
+
+    let mut global_map = parse_options(&global_content);
+    let instance_map = parse_options(&instance_content);
+
+    // Only apply changes (ignore deletions)
+    for (key, instance_value) in instance_map {
+        match global_map.get(&key) {
+            Some(global_value) if global_value == &instance_value => {}
+            _ => {
+                // changed or new → update global
+                global_map.insert(key, instance_value);
+            }
+        }
+    }
+
+    fs::write(global_path, serialize_options(&global_map))?;
+
+    Ok(())
+}
+
+fn options_path_global() -> PathBuf {
+    launcher_dir().join("options.txt")
+}
+
+fn options_path_instance(version: &GameVersion) -> PathBuf {
+    launcher_dir().join(&version.id).join("options.txt")
+}
+
 fn parse_options(content: &str) -> HashMap<String, String> {
     let mut map = HashMap::new();
 
@@ -52,3 +110,10 @@ fn parse_options(content: &str) -> HashMap<String, String> {
 
     map
 }
+
+fn serialize_options(map: &HashMap<String, String>) -> String {
+    map.iter()
+        .map(|(k, v)| format!("{k}:{v}"))
+        .collect::<Vec<_>>()
+        .join("\n")
+}
diff --git a/src-tauri/src/features/mod.rs b/src-tauri/src/features/mod.rs
index 76962ee..b4afedf 100644
--- a/src-tauri/src/features/mod.rs
+++ b/src-tauri/src/features/mod.rs
@@ -1,4 +1,5 @@
 use lyceris::auth::microsoft::MinecraftAccount;
+use serde::{Deserialize, Serialize};
 use tauri::State;
 use tokio::sync::Mutex;
 
@@ -8,6 +9,20 @@ mod instance_sync;
 
 pub type FeatureResult = Result<(), String>;
 
+#[derive(Clone, Serialize, Deserialize)]
+pub struct FeatureSettings {
+    // Instance Sync
+    sync_options: bool,
+}
+
+impl Default for FeatureSettings {
+    fn default() -> Self {
+        Self {
+            sync_options: false,
+        }
+    }
+}
+
 #[allow(unused_variables)]
 pub trait Feature: Send + Sync {
     fn launch(
diff --git a/src-tauri/src/lib.rs b/src-tauri/src/lib.rs
index c286f72..c6ed123 100644
--- a/src-tauri/src/lib.rs
+++ b/src-tauri/src/lib.rs
@@ -9,7 +9,7 @@ use std::{
     sync::{Arc, Mutex},
 };
 
-use crate::launcher::launcher_dir;
+use crate::{features::FeatureSettings, launcher::launcher_dir};
 
 pub type SharedState = Arc<Mutex<AppState>>;
 
@@ -36,6 +36,7 @@ pub struct GameVersion {
 #[derive(Clone, Serialize, Deserialize)]
 pub struct LauncherSettings {
     pub max_memory: u32,
+    pub features: FeatureSettings,
 }
 
 // --- App State ---
@@ -48,7 +49,10 @@ pub struct AppState {
 impl Default for AppState {
     fn default() -> Self {
         Self {
-            settings: LauncherSettings { max_memory: 4096 },
+            settings: LauncherSettings {
+                max_memory: 4096,
+                features: FeatureSettings::default(),
+            },
             version: String::from("1.21.6"),
         }
     }