Refactoring

lib/domain/services/ai_process_manager.dart

@@ -0,0 +1,88 @@
+import 'dart:io';
+
+import 'package:path/path.dart' as p;
+import 'package:path_provider/path_provider.dart';
+
+/// Manages the two llama.cpp server processes that provide AI features.
+///
+/// Both processes are kept alive for the lifetime of the app and must be
+/// killed on shutdown to prevent zombie processes from consuming RAM.
+///
+/// - Qwen 2.5 7B  → port 8080  (chat / completions)
+/// - Nomic Embed  → port 8081  (embeddings)
+class AiProcessManager {
+  Process? _qwenProcess;
+  Process? _nomicProcess;
+  bool _running = false;
+
+  // -------------------------------------------------------------------------
+  // Public API
+  // -------------------------------------------------------------------------
+
+  bool get isRunning => _running;
+
+  /// Starts both inference servers.  No-ops if already running or if the
+  /// llama-server binary is not present on disk.
+  Future<void> startServers() async {
+    if (_running) return;
+
+    final dir = await getApplicationDocumentsDirectory();
+    final base = dir.path;
+    final serverBin = p.join(
+      base,
+      Platform.isWindows ? 'llama-server.exe' : 'llama-server',
+    );
+
+    if (!File(serverBin).existsSync()) return;
+
+    try {
+      // ── Qwen 2.5 7B chat server ──────────────────────────────────────────
+      _qwenProcess = await Process.start(
+        serverBin,
+        [
+          '-m', p.join(base, 'qwen2.5-7b-instruct-q4_k_m.gguf'),
+          '--port', '8080',
+          '--ctx-size', '4096',
+          '-ngl', '99', // offload all layers to GPU
+        ],
+        runInShell: false,
+      );
+      // Drain pipes so the process is never blocked by a full buffer.
+      _qwenProcess!.stdout.drain<List<int>>();
+      _qwenProcess!.stderr.drain<List<int>>();
+
+      // ── Nomic embedding server ───────────────────────────────────────────
+      _nomicProcess = await Process.start(
+        serverBin,
+        [
+          '-m', p.join(base, 'nomic-embed-text-v1.5.Q4_K_M.gguf'),
+          '--port', '8081',
+          '--ctx-size', '8192',
+          '--embedding',
+        ],
+        runInShell: false,
+      );
+      _nomicProcess!.stdout.drain<List<int>>();
+      _nomicProcess!.stderr.drain<List<int>>();
+
+      _running = true;
+    } catch (_) {
+      // Clean up any partially-started processes before rethrowing.
+      _qwenProcess?.kill();
+      _nomicProcess?.kill();
+      _qwenProcess = null;
+      _nomicProcess = null;
+      rethrow;
+    }
+  }
+
+  /// Kills both processes and resets the running flag.
+  /// Safe to call even if servers were never started.
+  Future<void> stopServers() async {
+    _qwenProcess?.kill();
+    _nomicProcess?.kill();
+    _qwenProcess = null;
+    _nomicProcess = null;
+    _running = false;
+  }
+}