Implement patching

Quick note: Patching works, but the launcher attempts to unpatch the
game two times.

src-tauri/src/main.rs

@@ -222,6 +222,8 @@ fn main() -> Result<(), ArgsError> {
         system_helpers::wipe_registry,
         system_helpers::get_platform,
         system_helpers::run_un_elevated,
+        patch::patch_game,
+        patch::unpatch_game,
         proxy::set_proxy_addr,
         proxy::generate_ca_files,
         proxy::set_redirect_more,

src-tauri/src/patch.rs

@@ -3,6 +3,53 @@ use crate::file_helpers;
 use crate::system_helpers;
 use std::path::PathBuf;
 
+#[cfg(target_os = "linux")]
+use once_cell::sync::Lazy;
+#[cfg(target_os = "linux")]
+use std::sync::Arc;
+#[cfg(target_os = "linux")]
+use tokio::sync::Mutex;
+
+#[cfg(target_os = "linux")]
+static PATCH_STATE: Lazy<Arc<Mutex<Option<PatchState>>>> = Lazy::new(|| Arc::new(Mutex::new(None)));
+
+#[cfg(target_os = "linux")]
+#[derive(Debug, Clone, Copy)]
+enum PatchState {
+  NotExist,
+  Same,
+  BakNotExist,
+  BakExist,
+}
+
+#[cfg(target_os = "linux")]
+use PatchState::*;
+
+#[cfg(target_os = "linux")]
+impl PatchState {
+  fn to_wta(self) -> WhatToUnpach {
+    let (mhyp_renamed, game_was_patched) = match self {
+      NotExist => (false, true),
+      Same => (false, true),
+      BakNotExist => (true, true),
+      BakExist => (false, false),
+    };
+    WhatToUnpach {
+      mhyp_renamed,
+      game_was_patched,
+    }
+  }
+}
+
+#[cfg(target_os = "linux")]
+#[derive(Debug, Clone)]
+struct WhatToUnpach {
+  mhyp_renamed: bool,
+  game_was_patched: bool,
+}
+
+#[cfg(windows)]
+#[tauri::command]
 pub async fn patch_game() -> bool {
   let patch_path = PathBuf::from(system_helpers::install_location()).join("patch/version.dll");
 
@@ -37,6 +84,82 @@ pub async fn patch_game() -> bool {
   true
 }
 
+#[cfg(target_os = "linux")]
+#[tauri::command]
+pub async fn patch_game() -> bool {
+  let mut patch_state_mutex = PATCH_STATE.lock().await;
+  if patch_state_mutex.is_some() {
+    println!("Game already patched!");
+  }
+
+  let patch_path = PathBuf::from(system_helpers::install_location()).join("patch/version.dll");
+  let game_mhyp = PathBuf::from(get_game_rsa_path().await.unwrap()).join("mhypbase.dll");
+  let game_mhyp_bak = PathBuf::from(get_game_rsa_path().await.unwrap()).join("mhypbase.dll.bak");
+
+  let patch_state = if !game_mhyp.exists() {
+    NotExist
+  } else if file_helpers::are_files_identical(
+    patch_path.to_str().unwrap(),
+    game_mhyp.to_str().unwrap(),
+  ) {
+    Same
+  } else if !game_mhyp_bak.exists() {
+    BakNotExist
+  } else {
+    BakExist
+  };
+
+  match patch_state {
+    NotExist => {
+      // No renaming needed.
+      // Copy version.dll as mhypbase.dll
+      file_helpers::copy_file_with_new_name(
+        patch_path.clone().to_str().unwrap().to_string(),
+        get_game_rsa_path().await.unwrap(),
+        String::from("mhypbase.dll"),
+      );
+    }
+    Same => {
+      // No renaming needed.
+      // No copying needed.
+      println!("The game is already patched.");
+    }
+    BakNotExist => {
+      // The current mhypbase.dll is most likely the original
+
+      // Rename mhypbase.dll to mhypbase.dll.bak
+      file_helpers::rename(
+        game_mhyp.to_str().unwrap().to_string(),
+        game_mhyp_bak
+          .file_name()
+          .unwrap()
+          .to_str()
+          .unwrap()
+          .to_string(),
+      );
+      // Copy version.dll as mhypbase.dll
+      file_helpers::copy_file_with_new_name(
+        patch_path.clone().to_str().unwrap().to_string(),
+        get_game_rsa_path().await.unwrap(),
+        String::from("mhypbase.dll"),
+      );
+    }
+    BakExist => {
+      // Can't rename. mhypbase.dll.bak already exists.
+      // Can't patch. mhypbase.dll exists.
+      // This SHOULD NOT HAPPEN
+      println!("The game directory contains a mhypbase.dll, but it's different from the patch.");
+      println!("Make sure you have the original mhypbase.dll.");
+      println!("Delete any other copy, and place the original copy in the game directory with the original name.");
+    }
+  }
+
+  patch_state_mutex.replace(patch_state);
+  patch_state.to_wta().game_was_patched
+}
+
+#[cfg(windows)]
+#[tauri::command]
 pub async fn unpatch_game() -> bool {
   // Just delete patch since it's not replacing any existing file
   let deleted = file_helpers::delete_file(
@@ -50,6 +173,51 @@ pub async fn unpatch_game() -> bool {
   deleted
 }
 
+#[cfg(target_os = "linux")]
+#[tauri::command]
+pub async fn unpatch_game() -> bool {
+  // TODO: Prevent the launcher from unpatching the game two times
+  // This might be related to redirecting calls from the ts version of
+  // unpatchGame to the rust version
+  let mut patch_state_mutex = PATCH_STATE.lock().await;
+  let patch_state = patch_state_mutex.take();
+  if patch_state.is_none() {
+    println!("Game not patched!");
+    // NOTE: true is returned since otherwhise the launcher thinks unpatching failed
+    // NOTE: actually it should be false since delete_file always returns false
+    return false;
+  }
+  let patch_state = patch_state.unwrap();
+
+  let game_mhyp = PathBuf::from(get_game_rsa_path().await.unwrap()).join("mhypbase.dll");
+  let game_mhyp_bak = PathBuf::from(get_game_rsa_path().await.unwrap()).join("mhypbase.dll.bak");
+
+  let WhatToUnpach {
+    mhyp_renamed,
+    game_was_patched,
+  } = patch_state.to_wta();
+
+  // If the current mhypbase.dll is the patch, then delete it.
+  let deleted = if game_was_patched {
+    file_helpers::delete_file(game_mhyp.to_str().unwrap().to_string());
+    true
+  } else {
+    false
+  };
+  // If we renamed the original mhypbase.dll to mhypbase.dll.bak
+  // rename mhypbase.dll.bak back to mhypbase.dll
+  if mhyp_renamed {
+    file_helpers::rename(
+      game_mhyp_bak.to_str().unwrap().to_string(),
+      game_mhyp.to_str().unwrap().to_string(),
+    )
+  }
+
+  // NOTE: As mentioned in a note above, false should be returned if the function succeded
+  // and true if it failed
+  !deleted
+}
+
 pub async fn get_game_rsa_path() -> Option<String> {
   let config = config::get_config();
 

src/utils/rsa.ts

@@ -1,50 +1,10 @@
 import { invoke } from '@tauri-apps/api'
-import { getGameFolder } from './game'
 // Patch file from: https://github.com/34736384/RSAPatch/
 
 export async function patchGame() {
-  const patchPath = (await invoke('install_location')) + '/patch/version.dll'
-  // Are we already patched with mhypbase? If so, that's fine, just continue as normal
-  const gameIsPatched = await invoke('are_files_identical', {
-    path1: patchPath,
-    path2: (await getGameRSAPath()) + '/mhypbase.dll',
-  })
-
-  // Tell user they won't be unpatched with manual mhypbase patch
-  if (gameIsPatched) {
-    console.log('You are already patched using mhypbase, so you will not be auto patched and unpatched!')
-    return true
-  }
-
-  // Copy the patch to game files
-  const replaced = await invoke('copy_file_with_new_name', {
-    path: patchPath,
-    newPath: await getGameRSAPath(),
-    newName: 'version.dll',
-  })
-
-  if (!replaced) {
-    return false
-  }
-
-  return true
+  return invoke('patch_game')
 }
 
 export async function unpatchGame() {
-  // Just delete patch since it's not replacing any existing file
-  const deleted = await invoke('delete_file', {
-    path: (await getGameRSAPath()) + '/version.dll',
-  })
-
-  return deleted
-}
-
-export async function getGameRSAPath() {
-  const gameData = await getGameFolder()
-
-  if (!gameData) {
-    return null
-  }
-
-  return (gameData + '\\').replace(/\\/g, '/')
+  return invoke('unpatch_game')
 }