1 files changed, 359 insertions, 0 deletions
diff --git a/libs/nak/src/installers/symlinks.rs b/libs/nak/src/installers/symlinks.rs
new file mode 100644
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+++ b/libs/nak/src/installers/symlinks.rs
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+//! Symlink management for NaK prefixes
+//!
+//! Creates symlinks FROM NaK prefix TO game prefixes.
+//! Data stays in the game prefix, NaK just has links pointing to it.
+//!
+//! This inverted approach means:
+//! - Game saves remain in their original location (Steam cloud sync works)
+//! - NaK prefix provides unified access to all game data
+//! - No data duplication or sync issues
+//!
+//! NaK Tools folder contains convenience symlinks pointing INTO the prefix
+//! for easy access to Documents, AppData, etc.
+
+// Allow unused items - some functions are public API for future use
+#![allow(dead_code)]
+
+use std::fs;
+use std::path::Path;
+
+use crate::game_finder::{detect_all_games, Game, GameScanResult};
+use crate::logging::{log_info, log_warning};
+
+// ============================================================================
+// Public API
+// ============================================================================
+
+/// Create symlinks from NaK prefix to game prefixes for all detected games
+///
+/// This creates symlinks in the NaK prefix pointing to the actual save/config
+/// folders in each game's own prefix. The symlink direction is:
+///
+/// NaK/Documents/My Games/Skyrim -> game_prefix/Documents/My Games/Skyrim
+/// NaK/AppData/Local/Skyrim -> game_prefix/AppData/Local/Skyrim
+///
+/// Data stays in the game prefix (preserving Steam Cloud sync), while NaK
+/// provides unified access through symlinks.
+pub fn create_game_symlinks(nak_prefix: &Path, games: &[Game]) {
+    let users_dir = nak_prefix.join("drive_c/users");
+    let username = find_prefix_username(&users_dir);
+    let user_dir = users_dir.join(&username);
+
+    let documents = user_dir.join("Documents");
+    let my_games = documents.join("My Games");
+    let appdata_local = user_dir.join("AppData/Local");
+    let appdata_roaming = user_dir.join("AppData/Roaming");
+
+    // Ensure base directories exist (real folders in NaK prefix)
+    let _ = fs::create_dir_all(&my_games);
+    let _ = fs::create_dir_all(&appdata_local);
+    let _ = fs::create_dir_all(&appdata_roaming);
+
+    let mut linked_count = 0;
+
+    for game in games {
+        // Skip games without prefixes
+        let Some(game_prefix) = &game.prefix_path else {
+            continue;
+        };
+
+        // Discover the game prefix's user directory
+        let game_users_dir = game_prefix.join("drive_c/users");
+        let game_username = find_prefix_username(&game_users_dir);
+        let game_user_dir = game_users_dir.join(&game_username);
+
+        // Scan and symlink ALL folders in the game prefix's Documents/My Games/
+        linked_count += scan_and_link_all(
+            &my_games,
+            &game_user_dir.join("Documents/My Games"),
+            "Documents/My Games",
+            &game.name,
+            game_prefix,
+        );
+
+        // Also link the Documents folder itself for non-My Games entries
+        // (some games put saves directly in Documents/<GameName>)
+        linked_count += scan_and_link_all(
+            &documents,
+            &game_user_dir.join("Documents"),
+            "Documents",
+            &game.name,
+            game_prefix,
+        );
+
+        // Scan and symlink ALL folders in AppData/Local/
+        linked_count += scan_and_link_all(
+            &appdata_local,
+            &game_user_dir.join("AppData/Local"),
+            "AppData/Local",
+            &game.name,
+            game_prefix,
+        );
+
+        // Scan and symlink ALL folders in AppData/Roaming/
+        linked_count += scan_and_link_all(
+            &appdata_roaming,
+            &game_user_dir.join("AppData/Roaming"),
+            "AppData/Roaming",
+            &game.name,
+            game_prefix,
+        );
+    }
+
+    if linked_count > 0 {
+        log_info(&format!(
+            "Created {} symlinks to game prefixes",
+            linked_count
+        ));
+    }
+
+    // Create "My Documents" symlink for compatibility
+    let my_documents = user_dir.join("My Documents");
+    if !my_documents.exists() && fs::symlink_metadata(&my_documents).is_err() {
+        if let Err(e) = std::os::unix::fs::symlink("Documents", &my_documents) {
+            log_warning(&format!("Failed to create My Documents symlink: {}", e));
+        }
+    }
+}
+
+/// Create NaK Tools convenience symlinks pointing INTO the prefix
+///
+/// Creates symlinks in NaK Tools folder for easy access:
+/// - NaK Tools/Prefix Documents -> prefix/drive_c/users/<user>/Documents
+/// - NaK Tools/Prefix AppData Local -> prefix/drive_c/users/<user>/AppData/Local
+/// - NaK Tools/Prefix AppData Roaming -> prefix/drive_c/users/<user>/AppData/Roaming
+pub fn create_nak_tools_symlinks(tools_dir: &Path, prefix_path: &Path) {
+    let users_dir = prefix_path.join("drive_c/users");
+    let username = find_prefix_username(&users_dir);
+    let user_dir = users_dir.join(&username);
+
+    // Symlink: NaK Tools/Prefix Documents -> prefix Documents
+    let documents_link = tools_dir.join("Prefix Documents");
+    let documents_target = user_dir.join("Documents");
+    create_or_update_symlink(&documents_link, &documents_target, "Prefix Documents");
+
+    // Symlink: NaK Tools/Prefix AppData Local -> prefix AppData/Local
+    let appdata_local_link = tools_dir.join("Prefix AppData Local");
+    let appdata_local_target = user_dir.join("AppData/Local");
+    create_or_update_symlink(&appdata_local_link, &appdata_local_target, "Prefix AppData Local");
+
+    // Symlink: NaK Tools/Prefix AppData Roaming -> prefix AppData/Roaming
+    let appdata_roaming_link = tools_dir.join("Prefix AppData Roaming");
+    let appdata_roaming_target = user_dir.join("AppData/Roaming");
+    create_or_update_symlink(&appdata_roaming_link, &appdata_roaming_target, "Prefix AppData Roaming");
+
+    log_info("Created NaK Tools convenience symlinks to prefix folders");
+}
+
+/// Create or update a symlink
+fn create_or_update_symlink(link_path: &Path, target: &Path, name: &str) {
+    // Remove existing symlink or file
+    if link_path.exists() || fs::symlink_metadata(link_path).is_ok() {
+        let _ = fs::remove_file(link_path);
+        let _ = fs::remove_dir_all(link_path);
+    }
+
+    // Create symlink
+    if let Err(e) = std::os::unix::fs::symlink(target, link_path) {
+        log_warning(&format!("Failed to create {} symlink: {}", name, e));
+    }
+}
+
+/// Create symlinks for all detected games
+///
+/// Convenience function that detects games and creates symlinks in one call.
+pub fn create_game_symlinks_auto(nak_prefix: &Path) -> GameScanResult {
+    let result = detect_all_games();
+    create_game_symlinks(nak_prefix, &result.games);
+    result
+}
+
+/// Ensure only the Temp directory exists in AppData/Local
+///
+/// MO2 and other tools require AppData/Local/Temp to exist.
+/// We create only this essential directory, leaving other game-specific
+/// folders to be symlinked from game prefixes.
+pub fn ensure_temp_directory(prefix_path: &Path) {
+    let users_dir = prefix_path.join("drive_c/users");
+    let username = find_prefix_username(&users_dir);
+    let user_dir = users_dir.join(&username);
+
+    let temp_dir = user_dir.join("AppData/Local/Temp");
+    if let Err(e) = fs::create_dir_all(&temp_dir) {
+        log_warning(&format!("Failed to create Temp directory: {}", e));
+    } else {
+        log_info("Ensured AppData/Local/Temp directory exists");
+    }
+}
+
+// ============================================================================
+// Internal Functions
+// ============================================================================
+
+/// Directories to skip when scanning prefix folders for symlinking.
+/// These are Wine/Proton internal or system dirs, not game data.
+const SKIP_DIRS: &[&str] = &[
+    "Temp", "Microsoft", "wine", "Public", "root",
+    "Application Data", "Cookies", "Local Settings",
+    "NetHood", "PrintHood", "Recent", "SendTo",
+    "Start Menu", "Templates", "My Documents", "My Music",
+    "My Pictures", "My Videos", "Desktop", "Downloads",
+    "Favorites", "Links", "Saved Games", "Searches",
+    "Contacts", "3D Objects",
+];
+
+/// Scan all subdirectories in a game prefix folder and create symlinks
+/// for each one in the corresponding NaK prefix folder.
+///
+/// Returns the number of symlinks created.
+fn scan_and_link_all(
+    nak_base: &Path,
+    game_base: &Path,
+    label: &str,
+    game_name: &str,
+    _game_prefix: &Path,
+) -> usize {
+    if !game_base.is_dir() {
+        return 0;
+    }
+
+    let Ok(entries) = fs::read_dir(game_base) else {
+        return 0;
+    };
+
+    let mut count = 0;
+    for entry in entries.flatten() {
+        // Only symlink directories (game folders), not loose files
+        if !entry.path().is_dir() {
+            continue;
+        }
+
+        let folder_name = entry.file_name().to_string_lossy().to_string();
+
+        // Skip Wine/system internal directories
+        if SKIP_DIRS.iter().any(|&s| s.eq_ignore_ascii_case(&folder_name)) {
+            continue;
+        }
+
+        // Skip if it's "My Games" and we're scanning Documents (handled separately)
+        if label == "Documents" && folder_name == "My Games" {
+            continue;
+        }
+
+        let nak_path = nak_base.join(&folder_name);
+        let source_path = entry.path();
+
+        if create_symlink_if_needed(&nak_path, &source_path, game_name, label, &folder_name) {
+            count += 1;
+        }
+    }
+
+    count
+}
+
+/// Create a symlink if the target doesn't already exist or is already correct.
+///
+/// Returns true if a symlink was created (or already existed correctly).
+fn create_symlink_if_needed(
+    nak_path: &Path,
+    source_path: &Path,
+    game_name: &str,
+    label: &str,
+    folder_name: &str,
+) -> bool {
+    // Check if target already exists
+    if nak_path.exists() || fs::symlink_metadata(nak_path).is_ok() {
+        // Check if it's already a symlink to the correct location
+        if let Ok(target) = fs::read_link(nak_path) {
+            if target == source_path {
+                return true; // Already correctly linked
+            }
+        }
+        // Something else exists here, don't overwrite
+        return false;
+    }
+
+    // Ensure parent directory exists
+    if let Some(parent) = nak_path.parent() {
+        let _ = fs::create_dir_all(parent);
+    }
+
+    // Create the symlink
+    match std::os::unix::fs::symlink(source_path, nak_path) {
+        Ok(()) => {
+            log_info(&format!(
+                "Linked {}/{} -> {} ({})",
+                label,
+                folder_name,
+                source_path.display(),
+                game_name,
+            ));
+            true
+        }
+        Err(e) => {
+            log_warning(&format!(
+                "Failed to create symlink for {} ({}/{}): {}",
+                game_name, label, folder_name, e
+            ));
+            false
+        }
+    }
+}
+
+/// Find the username from a Wine prefix users directory
+fn find_prefix_username(users_dir: &Path) -> String {
+    if let Ok(entries) = fs::read_dir(users_dir) {
+        for entry in entries.flatten() {
+            let name = entry.file_name().to_string_lossy().to_string();
+            if name != "Public" && name != "root" {
+                return name;
+            }
+        }
+    }
+    "steamuser".to_string()
+}
+
+// ============================================================================
+// Oblivion Lowercase INI Symlinks
+// ============================================================================
+
+/// Create lowercase INI symlinks for Oblivion (some tools expect lowercase)
+pub fn create_oblivion_ini_symlinks(prefix_path: &Path) {
+    let users_dir = prefix_path.join("drive_c/users");
+    let username = find_prefix_username(&users_dir);
+    let oblivion_dir = users_dir
+        .join(&username)
+        .join("Documents/My Games/Oblivion");
+
+    if !oblivion_dir.exists() {
+        return;
+    }
+
+    create_lowercase_ini_symlink(&oblivion_dir, "Oblivion.ini", "oblivion.ini");
+    create_lowercase_ini_symlink(&oblivion_dir, "OblivionPrefs.ini", "oblivionprefs.ini");
+}
+
+/// Create a lowercase symlink for an INI file
+fn create_lowercase_ini_symlink(dir: &Path, original: &str, lowercase: &str) {
+    let original_path = dir.join(original);
+    let lowercase_path = dir.join(lowercase);
+
+    // Only create if original exists and lowercase doesn't
+    if original_path.exists()
+        && !lowercase_path.exists()
+        && fs::symlink_metadata(&lowercase_path).is_err()
+    {
+        // Create relative symlink (just the filename)
+        if let Err(e) = std::os::unix::fs::symlink(original, &lowercase_path) {
+            log_warning(&format!(
+                "Failed to create lowercase symlink {} -> {}: {}",
+                lowercase, original, e
+            ));
+        } else {
+            log_info(&format!(
+                "Created lowercase INI symlink: {} -> {}",
+                lowercase, original
+            ));
+        }
+    }
+}