detect: replace exe-name heuristic with multi-stage resolution pipeline

Introduce resolve_game_name() as the single entry point for deriving a
display name from a game executable. Resolution order:
  1. Explicit name (caller-supplied)
  2. Static override table for known bad stems (FactoryGame, bg3, etc.)
  3. GOG goggame-*.info and Epic .egstore/*.item manifest JSON files
  4. PE VERSIONINFO scan (ProductName / FileDescription, first 8 MB)
  5. Heuristic fallback: parent directory name or CamelCase stem split

Remove prettify_game_name and humanise_stem; expose prettify_exe_name
as the public heuristic-only fallback. Resolved names are cached in a
process-wide LazyLock<Mutex<HashMap>> so repeated scans are free.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/detect.rs

@@ -2,7 +2,9 @@ use crate::config::{Config, Launcher};
 use anyhow::Result;
 use owo_colors::OwoColorize;
 use std::collections::{HashMap, HashSet};
+use std::io::Read as _;
 use std::path::{Path, PathBuf};
+use std::sync::{LazyLock, Mutex};
 
 #[derive(Debug, Clone)]
 pub struct DetectHit {
@@ -111,6 +113,38 @@ const SKIP_EXES: &[&str] = &[
     "aria2c",
 ];
 
+// --- Name resolution ---
+
+/// Cache of absolute exe path → resolved display name (populated lazily).
+static NAME_CACHE: LazyLock<Mutex<HashMap<PathBuf, String>>> =
+    LazyLock::new(|| Mutex::new(HashMap::new()));
+
+/// Exe stem (lowercase) → proper game name for known unhelpful exe filenames.
+const EXE_OVERRIDES: &[(&str, &str)] = &[
+    ("factorygame", "Satisfactory"),
+    ("wow", "World of Warcraft"),
+    ("wowclassic", "WoW Classic"),
+    ("d3", "Diablo III"),
+    ("d4", "Diablo IV"),
+    ("sc2", "StarCraft II"),
+    ("scii", "StarCraft II"),
+    ("sc", "StarCraft Remastered"),
+    ("valorant-win64-shipping", "VALORANT"),
+    ("fortniteclient-win64-shipping", "Fortnite"),
+    ("rocketleague", "Rocket League"),
+    ("bg3", "Baldur's Gate 3"),
+    ("bg3_dx11", "Baldur's Gate 3"),
+    ("nms", "No Man's Sky"),
+    ("cyberpunkgame", "Cyberpunk 2077"),
+    ("witcher3", "The Witcher 3"),
+    ("re2", "Resident Evil 2"),
+    ("re3", "Resident Evil 3"),
+    ("re4", "Resident Evil 4"),
+    ("re8", "Resident Evil Village"),
+    ("osi", "Divinity: Original Sin"),
+    ("aoc", "Age of Conan"),
+];
+
 /// Scan a launcher's Wine prefix for installed game executables.
 /// Returns (display_name, path_relative_to_drive_c) pairs, sorted alphabetically,
 /// excluding the launcher's own exe and any already-configured games.
@@ -191,27 +225,197 @@ fn scan_exe_dir(
             if !seen.insert(rel_lower) {
                 continue;
             }
-            let display = prettify_game_name(&path);
+            let display = resolve_game_name(&path, None);
             out.push((display, rel_str));
         }
     }
 }
 
-/// Derive a human-readable game name from an exe path.
+/// Resolve a human-readable display name for a game exe.
 ///
-/// Strategy: use the parent directory name (e.g. "Call of Duty" from
+/// Resolution pipeline (first hit wins):
-/// `Program Files/Call of Duty/game.exe`) unless it looks generic
+/// 1. Explicit name — if `explicit_name` is `Some`, return it immediately.
-/// (like "Bin", "x64", "Binaries"), in which case walk up. Falls back
+/// 2. Static override — known bad exe stems (e.g. `factorygame` → "Satisfactory").
-/// to humanising the exe file stem by inserting spaces before capitals.
+/// 3. Store/platform metadata — reserved for future integration.
-fn prettify_game_name(path: &Path) -> String {
+/// 4. Game manifest files — GOG `.info` and Epic `.egstore/*.item` JSON.
-    // Generic directory names that don't make good game labels
+/// 5. PE VERSIONINFO — `ProductName` / `FileDescription` from the binary.
+/// 6. Heuristic fallback — parent directory name or humanised exe stem.
+///
+/// Results from stages 2–6 are cached by path after first computation.
+pub fn resolve_game_name(exe_path: &Path, explicit_name: Option<&str>) -> String {
+    if let Some(name) = explicit_name {
+        return name.to_string();
+    }
+
+    {
+        let cache = NAME_CACHE.lock().unwrap_or_else(|e| e.into_inner());
+        if let Some(cached) = cache.get(exe_path) {
+            return cached.clone();
+        }
+    }
+
+    let name = resolve_uncached(exe_path);
+
+    NAME_CACHE
+        .lock()
+        .unwrap_or_else(|e| e.into_inner())
+        .insert(exe_path.to_path_buf(), name.clone());
+
+    name
+}
+
+fn resolve_uncached(exe_path: &Path) -> String {
+    let stem = exe_path
+        .file_stem()
+        .and_then(|s| s.to_str())
+        .unwrap_or("");
+    let stem_lower = stem.to_lowercase();
+
+    // Stage 2 – static override
+    for &(bad, good) in EXE_OVERRIDES {
+        if stem_lower == bad {
+            return good.to_string();
+        }
+    }
+
+    // Stage 3 – store/platform metadata (future integration point)
+
+    // Stage 4 – game manifest files
+    if let Some(name) = read_manifest_name(exe_path) {
+        return name;
+    }
+
+    // Stage 5 – PE VERSIONINFO
+    if let Some(name) = read_pe_name(exe_path) {
+        return name;
+    }
+
+    // Stage 6 – heuristic fallback
+    prettify_exe_name(exe_path)
+}
+
+/// Parse GOG `.info` and Epic `.egstore/*.item` manifest files near `exe_path`.
+fn read_manifest_name(exe_path: &Path) -> Option<String> {
+    let dir = exe_path.parent()?;
+
+    // GOG: goggame-<id>.info files contain { "gameName": "..." }
+    if let Ok(entries) = std::fs::read_dir(dir) {
+        for entry in entries.flatten() {
+            let fname = entry.file_name();
+            let fname = fname.to_string_lossy();
+            if fname.starts_with("goggame-") && fname.ends_with(".info") {
+                if let Ok(text) = std::fs::read_to_string(entry.path()) {
+                    if let Ok(json) = serde_json::from_str::<serde_json::Value>(&text) {
+                        if let Some(title) = json.get("gameName").and_then(|v| v.as_str()) {
+                            let t = title.trim();
+                            if !t.is_empty() {
+                                return Some(t.to_string());
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    // Epic: .egstore/*.item files contain { "DisplayName": "..." }
+    let egstore = dir.join(".egstore");
+    if egstore.is_dir() {
+        if let Ok(entries) = std::fs::read_dir(&egstore) {
+            for entry in entries.flatten() {
+                if entry.path().extension().and_then(|e| e.to_str()) == Some("item") {
+                    if let Ok(text) = std::fs::read_to_string(entry.path()) {
+                        if let Ok(json) = serde_json::from_str::<serde_json::Value>(&text) {
+                            if let Some(title) = json.get("DisplayName").and_then(|v| v.as_str()) {
+                                let t = title.trim();
+                                if !t.is_empty() {
+                                    return Some(t.to_string());
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    None
+}
+
+/// Read `ProductName` or `FileDescription` from the PE VERSIONINFO resource.
+/// Reads at most 8 MB of the file to stay fast on large game binaries.
+fn read_pe_name(exe_path: &Path) -> Option<String> {
+    let mut file = std::fs::File::open(exe_path).ok()?;
+    let mut data = vec![0u8; 8 * 1024 * 1024];
+    let n = file.read(&mut data).ok()?;
+    data.truncate(n);
+    if data.len() < 2 || data[0] != b'M' || data[1] != b'Z' {
+        return None;
+    }
+    for key in &["ProductName", "FileDescription"] {
+        if let Some(name) = find_pe_version_string(&data, key) {
+            return Some(name);
+        }
+    }
+    None
+}
+
+/// Scan raw PE bytes for a UTF-16LE VERSIONINFO string entry by key.
+fn find_pe_version_string(data: &[u8], key: &str) -> Option<String> {
+    // Encode key as null-terminated UTF-16LE
+    let key_bytes: Vec<u8> = key
+        .encode_utf16()
+        .chain(std::iter::once(0u16))
+        .flat_map(|c| c.to_le_bytes())
+        .collect();
+
+    let mut search = 0usize;
+    while search + key_bytes.len() <= data.len() {
+        let Some(rel) = data[search..].windows(key_bytes.len()).position(|w| w == key_bytes.as_slice()) else {
+            break;
+        };
+        let key_end = search + rel + key_bytes.len();
+        // Value immediately follows the key, aligned to a 4-byte boundary.
+        let value_start = (key_end + 3) & !3;
+        // Read UTF-16LE characters until null or non-printable.
+        let mut chars: Vec<u16> = Vec::new();
+        let mut i = value_start;
+        while i + 1 < data.len() && chars.len() < 256 {
+            let c = u16::from_le_bytes([data[i], data[i + 1]]);
+            if c == 0 {
+                break;
+            }
+            if c < 0x20 && c != 0x09 {
+                chars.clear();
+                break;
+            }
+            chars.push(c);
+            i += 2;
+        }
+        if chars.len() >= 2 {
+            if let Ok(s) = String::from_utf16(&chars) {
+                let t = s.trim().to_string();
+                if !t.is_empty() && t.len() < 200 {
+                    return Some(t);
+                }
+            }
+        }
+        search += rel + 1;
+    }
+    None
+}
+
+/// Heuristic last-resort name derivation from an exe path.
+///
+/// Walks up parent directories looking for a non-generic name; falls back to
+/// inserting spaces into the CamelCase / digit-boundary exe stem.
+pub fn prettify_exe_name(path: &Path) -> String {
     const GENERIC_DIRS: &[&str] = &[
         "bin", "binaries", "x64", "x86", "win64", "win32", "retail",
         "shipping", "game", "runtime", "_retail_", "_commonredist",
         "launcher", "engine", "client",
     ];
 
-    // Try parent directories (closest first, up to 3 levels)
     let mut dir = path.parent();
     for _ in 0..3 {
         let Some(d) = dir else { break };
@@ -226,34 +430,24 @@ fn prettify_game_name(path: &Path) -> String {
         dir = d.parent();
     }
 
-    // Fallback: humanise the exe stem ("BlackOps6" → "Black Ops 6")
     let stem = path
         .file_stem()
         .and_then(|s| s.to_str())
         .unwrap_or("Unknown");
-    humanise_stem(stem)
-}
 
-/// Insert spaces before uppercase runs and digit boundaries.
+    // Insert spaces at CamelCase and digit boundaries.
-/// "BlackOps6" → "Black Ops 6", "HITMAN3" → "HITMAN 3"
+    let mut out = String::with_capacity(stem.len() + 4);
-fn humanise_stem(s: &str) -> String {
+    let chars: Vec<char> = stem.chars().collect();
-    let mut out = String::with_capacity(s.len() + 4);
-    let chars: Vec<char> = s.chars().collect();
     for (i, &c) in chars.iter().enumerate() {
         if i > 0 {
             let prev = chars[i - 1];
-            // Letter→digit or digit→letter boundary
             if (prev.is_alphabetic() && c.is_ascii_digit())
                 || (prev.is_ascii_digit() && c.is_alphabetic())
             {
                 out.push(' ');
-            }
+            } else if prev.is_lowercase() && c.is_uppercase() {
-            // lowercase→uppercase ("nO" in "BlackOps")
-            else if prev.is_lowercase() && c.is_uppercase() {
                 out.push(' ');
-            }
+            } else if i + 1 < chars.len()
-            // UPPER run ending: "ABCdef" → "AB Cdef"
-            else if i + 1 < chars.len()
                 && prev.is_uppercase()
                 && c.is_uppercase()
                 && chars[i + 1].is_lowercase()
@@ -261,7 +455,6 @@ fn humanise_stem(s: &str) -> String {
                 out.push(' ');
             }
         }
-        // Replace underscores / hyphens with spaces
         if c == '_' || c == '-' {
             out.push(' ');
         } else {