fix(launch): check assets for old versions

src-tauri/src/launch/helpers/command_generator.rs

@@ -6,7 +6,7 @@ use crate::instance::helpers::game_version::compare_game_versions;
 use crate::instance::helpers::misc::get_instance_subdir_paths;
 use crate::instance::models::misc::{InstanceError, InstanceSubdirType};
 use crate::launch::helpers::file_validator::get_nonnative_library_paths;
-use crate::launch::helpers::misc::{get_separator, replace_arguments};
+use crate::launch::helpers::misc::{check_virtual_assets, get_separator, replace_arguments};
 use crate::launch::models::{LaunchError, LaunchingState};
 use crate::launcher_config::models::*;
 use crate::utils::sys_info::get_memory_info;
@@ -23,6 +23,7 @@ use tauri::{AppHandle, Manager};
 #[derive(Serialize, Deserialize, Default)]
 pub struct LaunchArguments {
   // basic game params
+  pub game_assets: String,
   pub assets_root: String,
   pub assets_index_name: String,
   pub game_directory: String,
@@ -167,8 +168,12 @@ pub async fn generate_launch_command(
   };
 
   let arguments_value = LaunchArguments {
+    game_assets: assets_dir
+      .join("virtual/legacy")
+      .to_string_lossy()
+      .to_string(),
     assets_root: assets_dir.to_string_lossy().to_string(),
-    assets_index_name: client_info.asset_index.id,
+    assets_index_name: client_info.asset_index.id.clone(),
     game_directory: root_dir.to_string_lossy().to_string(),
 
     version_name: selected_instance.name.clone(),
@@ -353,6 +358,8 @@ pub async fn generate_launch_command(
       .clone(),
   );
 
+  check_virtual_assets(root_dir, assets_dir, &client_info.asset_index.id).await?;
+
   if let Some(client_args) = &client_info.arguments {
     let client_game_args = client_args.to_game_arguments(&launch_feature)?;
     cmd.extend(replace_arguments(client_game_args, &map));

src-tauri/src/launch/helpers/misc.rs

@@ -1,6 +1,55 @@
+use futures::future::join_all;
 use lazy_static;
 use regex::Regex;
 use std::collections::HashMap;
+use std::path::Path;
+use tokio::fs;
+
+use crate::error::SJMCLResult;
+use crate::instance::helpers::asset_index::AssetIndex;
+use crate::storage::load_json_async;
+
+pub async fn check_virtual_assets(
+  root_dir: &Path,
+  assets_dir: &Path,
+  assets_index_name: &str,
+) -> SJMCLResult<()> {
+  if assets_index_name != "legacy" && assets_index_name != "pre-1.6" {
+    return Ok(());
+  }
+  let asset_index =
+    load_json_async::<AssetIndex>(&assets_dir.join(format!("indexes/{}.json", assets_index_name)))
+      .await?;
+
+  let futs = asset_index
+    .objects
+    .into_iter()
+    .map(|(name, item)| async move {
+      let path_in_repo = format!("{}/{}", &item.hash[..2], item.hash);
+      let origin = assets_dir.join(format!("objects/{}", path_in_repo));
+      let target = match assets_index_name {
+        "legacy" => assets_dir.join(format!("virtual/legacy/{}", name)),
+        "pre-1.6" => root_dir.join(format!("resources/{}", name)),
+        _ => unreachable!(),
+      };
+
+      if fs::try_exists(&origin).await? {
+        if !fs::try_exists(&target).await? {
+          copy_with_dirs(&origin, &target).await?;
+        }
+      }
+      Ok(())
+    });
+  let _: Vec<SJMCLResult<()>> = join_all(futs).await;
+  Ok(())
+}
+
+async fn copy_with_dirs(origin: &Path, target: &Path) -> std::io::Result<u64> {
+  if let Some(parent) = target.parent() {
+    fs::create_dir_all(parent).await?;
+  }
+  fs::copy(origin, target).await
+}
 
 pub fn replace_arguments(args: Vec<String>, map: &HashMap<String, String>) -> Vec<String> {
   lazy_static::lazy_static!(