WP2: Create AgentSession basic structure + update plan for keep-old-code strategy

packages/coding-agent/src/core/agent-session.ts

@@ -0,0 +1,109 @@
+/**
+ * AgentSession - Core abstraction for agent lifecycle and session management.
+ *
+ * This class is shared between all run modes (interactive, print, rpc).
+ * It encapsulates:
+ * - Agent state access
+ * - Event subscription with automatic session persistence
+ * - Model and thinking level management
+ * - Compaction (manual and auto)
+ * - Bash execution
+ * - Session switching and branching
+ *
+ * Modes use this class and add their own I/O layer on top.
+ */
+
+import type { Agent, AgentState, AppMessage, ThinkingLevel } from "@mariozechner/pi-agent-core";
+import type { Model } from "@mariozechner/pi-ai";
+import type { SessionManager } from "../session-manager.js";
+import type { SettingsManager } from "../settings-manager.js";
+import type { FileSlashCommand } from "../slash-commands.js";
+
+// ============================================================================
+// Types
+// ============================================================================
+
+export interface AgentSessionConfig {
+	agent: Agent;
+	sessionManager: SessionManager;
+	settingsManager: SettingsManager;
+	/** Models to cycle through with Ctrl+P (from --models flag) */
+	scopedModels?: Array<{ model: Model<any>; thinkingLevel: ThinkingLevel }>;
+	/** File-based slash commands for expansion */
+	fileCommands?: FileSlashCommand[];
+}
+
+// ============================================================================
+// AgentSession Class
+// ============================================================================
+
+export class AgentSession {
+	readonly agent: Agent;
+	readonly sessionManager: SessionManager;
+	readonly settingsManager: SettingsManager;
+
+	private _scopedModels: Array<{ model: Model<any>; thinkingLevel: ThinkingLevel }>;
+	private _fileCommands: FileSlashCommand[];
+
+	constructor(config: AgentSessionConfig) {
+		this.agent = config.agent;
+		this.sessionManager = config.sessionManager;
+		this.settingsManager = config.settingsManager;
+		this._scopedModels = config.scopedModels ?? [];
+		this._fileCommands = config.fileCommands ?? [];
+	}
+
+	// =========================================================================
+	// Read-only State Access
+	// =========================================================================
+
+	/** Full agent state */
+	get state(): AgentState {
+		return this.agent.state;
+	}
+
+	/** Current model (may be null if not yet selected) */
+	get model(): Model<any> | null {
+		return this.agent.state.model;
+	}
+
+	/** Current thinking level */
+	get thinkingLevel(): ThinkingLevel {
+		return this.agent.state.thinkingLevel;
+	}
+
+	/** Whether agent is currently streaming a response */
+	get isStreaming(): boolean {
+		return this.agent.state.isStreaming;
+	}
+
+	/** All messages including custom types like BashExecutionMessage */
+	get messages(): AppMessage[] {
+		return this.agent.state.messages;
+	}
+
+	/** Current queue mode */
+	get queueMode(): "all" | "one-at-a-time" {
+		return this.agent.getQueueMode();
+	}
+
+	/** Current session file path */
+	get sessionFile(): string {
+		return this.sessionManager.getSessionFile();
+	}
+
+	/** Current session ID */
+	get sessionId(): string {
+		return this.sessionManager.getSessionId();
+	}
+
+	/** Scoped models for cycling (from --models flag) */
+	get scopedModels(): ReadonlyArray<{ model: Model<any>; thinkingLevel: ThinkingLevel }> {
+		return this._scopedModels;
+	}
+
+	/** File-based slash commands */
+	get fileCommands(): ReadonlyArray<FileSlashCommand> {
+		return this._fileCommands;
+	}
+}

packages/coding-agent/src/core/bash-executor.ts

@@ -35,7 +35,7 @@ export interface BashResult {
 	cancelled: boolean;
 	/** Whether the output was truncated */
 	truncated: boolean;
-	/** Path to temp file containing full output (if output exceeded threshold) */
+	/** Path to temp file containing full output (if output exceeded truncation threshold) */
 	fullOutputPath?: string;
 }
 

packages/coding-agent/src/core/index.ts

@@ -2,4 +2,5 @@
  * Core modules shared between all run modes.
  */
 
+export { AgentSession, type AgentSessionConfig } from "./agent-session.js";
 export { type BashExecutorOptions, type BashResult, executeBash } from "./bash-executor.js";