Add data_dir config option for custom PrismLauncher directory

README.md

@@ -103,13 +103,34 @@ Press `/` to enter search mode. Type to filter the list incrementally. Press `En
 
 ## Configuration
 
-prism-tui reads its configuration from PrismLauncher's data directory:
+### PrismLauncher Data Directory
 
-- **Linux**: `~/.local/share/PrismLauncher/`
+prism-tui automatically detects your PrismLauncher data directory:
+
+- **Linux**: `~/.local/share/PrismLauncher/` or Flatpak location
 - **macOS**: `~/Library/Application Support/PrismLauncher/`
 - **Windows**: `%APPDATA%/PrismLauncher/`
 
-No additional configuration is required.
+For custom or portable installations, you can override the data directory in two ways (checked in this order):
+
+1. **Environment variable**: `PRISMLAUNCHER_DATA=/path/to/data prism-tui`
+2. **Config file**: Set `data_dir` in the config (see below)
+
+### Config File
+
+prism-tui stores its settings in a TOML config file:
+
+- **Linux**: `~/.config/prism-tui/config.toml`
+- **macOS**: `~/Library/Application Support/prism-tui/config.toml`
+- **Windows**: `%APPDATA%\prism-tui\config.toml`
+
+```toml
+default_sort = "Last Played"
+sort_ascending = true
+data_dir = "~/Games/PrismLauncher"  # optional, overrides auto-detection
+```
+
+Sort and sort-direction preferences are saved automatically. The `data_dir` option supports `~` tilde expansion.
 
 ## Architecture
 

src/app.rs

@@ -203,7 +203,7 @@ pub struct App {
 }
 
 impl App {
-    pub fn new(config: PrismConfig) -> Result<Self> {
+    pub fn new(config: PrismConfig, app_config: AppConfig) -> Result<Self> {
         use crate::data::{load_accounts, load_groups, load_instances};
 
         let instances_dir = config.instances_dir();
@@ -213,8 +213,6 @@ impl App {
 
         let active_account = accounts.iter().find(|a| a.is_active).cloned();
 
-        let app_config = AppConfig::load();
-
         let sort_mode = app_config.default_sort_mode();
         let sort_ascending = app_config.sort_ascending;
 

src/data/app_config.rs

@@ -9,6 +9,8 @@ pub struct AppConfig {
     pub default_sort: String,
     #[serde(default = "default_true")]
     pub sort_ascending: bool,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub data_dir: Option<String>,
 }
 
 fn default_true() -> bool {
@@ -24,6 +26,7 @@ impl Default for AppConfig {
         Self {
             default_sort: default_sort(),
             sort_ascending: true,
+            data_dir: None,
         }
     }
 }
@@ -65,6 +68,10 @@ impl AppConfig {
         }
     }
 
+    pub fn resolved_data_dir(&self) -> Option<PathBuf> {
+        self.data_dir.as_ref().map(|p| expand_tilde(p))
+    }
+
     pub fn default_sort_mode(&self) -> SortMode {
         match self.default_sort.as_str() {
             "Name" => SortMode::Name,
@@ -75,3 +82,17 @@ impl AppConfig {
         }
     }
 }
+
+fn expand_tilde(path: &str) -> PathBuf {
+    let rest = path.strip_prefix("~/").or_else(|| path.strip_prefix("~\\"));
+    if let Some(rest) = rest {
+        if let Some(home) = dirs::home_dir() {
+            return home.join(rest);
+        }
+    } else if path == "~"
+        && let Some(home) = dirs::home_dir()
+    {
+        return home;
+    }
+    PathBuf::from(path)
+}

src/data/config.rs

@@ -38,24 +38,39 @@ impl PrismConfig {
     }
 }
 
-pub fn find_prism_data_dir() -> Result<PathBuf> {
-    // Check environment variable first
+pub fn find_prism_data_dir(config_data_dir: Option<PathBuf>) -> Result<PathBuf> {
+    // 1. Check environment variable first
     if let Ok(path) = env::var("PRISMLAUNCHER_DATA") {
         let path = PathBuf::from(path);
         if path.exists() {
             return Ok(path);
         }
+        return Err(PrismError::Config(format!(
+            "PRISMLAUNCHER_DATA directory does not exist: {}",
+            path.display()
+        )));
     }
 
-    // Standard location
+    // 2. Config file data_dir
+    if let Some(path) = config_data_dir {
+        if path.exists() {
+            return Ok(path);
+        }
+        return Err(PrismError::Config(format!(
+            "Configured data_dir does not exist: {}",
+            path.display()
+        )));
+    }
+
+    // 3. Standard platform location
     if let Some(data_dir) = dirs::data_dir() {
         let standard = data_dir.join("PrismLauncher");
         if standard.exists() {
             return Ok(standard);
         }
     }
 
-    // Flatpak location (Linux only)
+    // 4. Flatpak location (Linux only)
     #[cfg(target_os = "linux")]
     {
         if let Some(home) = dirs::home_dir() {

src/main.rs

@@ -10,7 +10,7 @@ mod view;
 
 use app::App;
 use color_eyre::Result;
-use data::{PrismConfig, find_prism_data_dir};
+use data::{AppConfig, PrismConfig, find_prism_data_dir};
 use message::Message;
 use std::time::Duration;
 use tui::{Event, EventStream, Terminal};
@@ -19,9 +19,10 @@ use tui::{Event, EventStream, Terminal};
 async fn main() -> Result<()> {
     color_eyre::install()?;
 
-    let data_dir = find_prism_data_dir()?;
+    let app_config = AppConfig::load();
+    let data_dir = find_prism_data_dir(app_config.resolved_data_dir())?;
     let config = PrismConfig::load(&data_dir)?;
-    let mut app = App::new(config)?;
+    let mut app = App::new(config, app_config)?;
     let mut terminal = Terminal::new()?;
     let mut events = EventStream::new(Duration::from_millis(250));