Use winreg to look up epic location

Cargo.lock

@@ -103,6 +103,7 @@ dependencies = [
  "steamgriddb_api",
  "tokio",
  "toml",
+ "winreg 0.10.1",
 ]
 
 [[package]]
@@ -1037,7 +1038,7 @@ dependencies = [
  "wasm-bindgen",
  "wasm-bindgen-futures",
  "web-sys",
- "winreg",
+ "winreg 0.7.0",
 ]
 
 [[package]]
@@ -1549,6 +1550,15 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "winreg"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "80d0f4e272c85def139476380b12f9ac60926689dd2e01d4923222f40580869d"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "wyz"
 version = "0.2.0"

Cargo.toml

@@ -21,6 +21,7 @@ flate2 = "^1.0.22"
 toml = { version = "^0.5.8", optional = true }
 futures = { version = "^0.3.17" }
 dashmap = { version = "^4.0.2", features = ["serde"] }
+winreg = "0.10.1"
 
 [build-dependencies]
 fl2rust = { version = "0.4", optional = true }

src/egs/get_manifests.rs

@@ -81,16 +81,10 @@ pub fn get_default_location() -> Option<PathBuf> {
 
     #[cfg(target_os = "windows")]
     {
-        let key = "SYSTEMDRIVE";
-        let system_drive =
-            env::var(key).expect("We are on windows, we must know what the SYSTEMDRIVE is");
-
-        let path = Path::new(format!("{}\\", system_drive).as_str())
-            .join("ProgramData")
-            .join("Epic")
-            .join("EpicGamesLauncher")
-            .join("Data")
-            .join("Manifests");
+        let path = match  location_from_registry(){
+            Some(path) => path,
+            None => guess_default_location()
+        };
         if path.exists() {
             Some(path)
         } else {
@@ -98,6 +92,38 @@ pub fn get_default_location() -> Option<PathBuf> {
         }
     }
 }
+#[cfg(target_os = "windows")]
+fn location_from_registry() -> Option<PathBuf> {
+    use winreg::enums::*;
+    use winreg::RegKey;
+
+    let hklm = RegKey::predef(HKEY_LOCAL_MACHINE);
+    if let Ok(launcher) = hklm.open_subkey("SOFTWARE\\WOW6432Node\\Epic Games\\EpicGamesLauncher") {
+        let path_string: Result<String, _> = launcher.get_value("AppDataPath");
+        if let Ok(path_string) = path_string {
+            let path = Path::new(&path_string).join("Manifests");
+            if path.exists() {
+                return Some(path.to_path_buf());
+            }
+        }
+    }
+    None
+}
+
+#[cfg(target_os = "windows")]
+fn guess_default_location() -> PathBuf {
+    let key = "SYSTEMDRIVE";
+    let system_drive =
+        env::var(key).expect("We are on windows, we must know what the SYSTEMDRIVE is");
+
+    let path = Path::new(format!("{}\\", system_drive).as_str())
+        .join("ProgramData")
+        .join("Epic")
+        .join("EpicGamesLauncher")
+        .join("Data")
+        .join("Manifests");
+    path.to_path_buf()
+}
 
 fn is_game_installed(manifest: &ManifestItem) -> bool {
     Path::new(manifest.manifest_location.as_str()).exists()