feat: US-010 - Add RecordLastChannel to AgentLoop with atomic state save

- Add state *state.Manager field to AgentLoop struct
- Initialize stateManager in NewAgentLoop using state.NewManager
- Implement RecordLastChannel method that calls state.SetLastChannel
- Implement RecordLastChatID method for chat ID tracking
- Add comprehensive tests for state persistence
- Verify state survives across AgentLoop instances

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

.ralph/prd.json

@@ -151,7 +151,7 @@
         "go test ./pkg/agent -run TestRecordLastChannel passes"
       ],
       "priority": 10,
-      "passes": false,
+      "passes": true,
       "notes": ""
     },
     {

.ralph/progress.txt

@@ -6,7 +6,7 @@ Tool 返回值结构化重构 - 将 Tool 接口返回值从 (string, error) 改
 
 ## Progress
 
-### Completed (8/21)
+### Completed (9/21)
 
 - US-001: Add ToolResult struct and helper functions
 - US-002: Modify Tool interface to return *ToolResult
@@ -16,6 +16,7 @@ Tool 返回值结构化重构 - 将 Tool 接口返回值从 (string, error) 改
 - US-007: Heartbeat async task execution support
 - US-008: Inject callback into async tools in AgentLoop
 - US-009: State save atomicity - SetLastChannel
+- US-010: Update RecordLastChannel to use atomic save
 
 ### In Progress
 
@@ -32,7 +33,7 @@ Tool 返回值结构化重构 - 将 Tool 接口返回值从 (string, error) 改
 | US-007 | Heartbeat async task execution support | Completed | |
 | US-008 | Inject callback into async tools in AgentLoop | Completed | |
 | US-009 | State save atomicity - SetLastChannel | Completed | |
-| US-010 | Update RecordLastChannel to use atomic save | Pending | |
+| US-010 | Update RecordLastChannel to use atomic save | Completed | |
 | US-011 | Refactor MessageTool to use ToolResult | Completed | |
 | US-012 | Refactor ShellTool to use ToolResult | Completed | |
 | US-013 | Refactor FilesystemTool to use ToolResult | Completed | |
@@ -175,4 +176,24 @@ Tool 返回值结构化重构 - 将 Tool 接口返回值从 (string, error) 改
   - **Gotchas encountered:** 临时文件必须与目标文件在同一文件系统中，否则 `os.Rename` 会失败。
   - **Useful context:** 这个模式将在 US-010 中用于 `RecordLastChannel`，确保状态更新的原子性。
 
+---
+
+## [2026-02-12] - US-010
+- What was implemented:
+  - 在 AgentLoop 中添加 `state *state.Manager` 字段
+  - 在 `NewAgentLoop` 中初始化 `stateManager := state.NewManager(workspace)`
+  - 实现 `RecordLastChannel(channel string)` 方法，调用 `al.state.SetLastChannel(al.workspace, channel)`
+  - 实现 `RecordLastChatID(chatID string)` 方法，调用 `al.state.SetLastChatID(al.workspace, chatID)`
+  - 添加完整的测试：`TestRecordLastChannel`、`TestRecordLastChatID`、`TestNewAgentLoop_StateInitialized`
+  - 验证状态持久化：创建新的 AgentLoop 实例后状态仍然保留
+
+- Files changed:
+  - `pkg/agent/loop.go`
+  - `pkg/agent/loop_test.go` (新增)
+
+- **Learnings for future iterations:**
+  - **Patterns discovered:** 状态管理应该集中在一个专门的包中（如 `pkg/state`），而不是分散在各个模块中。
+  - **Gotchas encountered:** 测试中的 mock Provider 需要实现完整的 `LLMProvider` 接口，包括 `GetDefaultModel()` 方法。
+  - **Useful context:** `RecordLastChannel` 方法现在可以用于跟踪用户最后一次活跃的频道，这对于跨会话的上下文恢复很有用。
+
 ---

pkg/agent/loop.go

@@ -22,6 +22,7 @@ import (
 	"github.com/sipeed/picoclaw/pkg/logger"
 	"github.com/sipeed/picoclaw/pkg/providers"
 	"github.com/sipeed/picoclaw/pkg/session"
+	"github.com/sipeed/picoclaw/pkg/state"
 	"github.com/sipeed/picoclaw/pkg/tools"
 	"github.com/sipeed/picoclaw/pkg/utils"
 )
@@ -34,6 +35,7 @@ type AgentLoop struct {
 	contextWindow  int           // Maximum context window size in tokens
 	maxIterations  int
 	sessions       *session.SessionManager
+	state          *state.Manager
 	contextBuilder *ContextBuilder
 	tools          *tools.ToolRegistry
 	running        atomic.Bool
@@ -88,6 +90,9 @@ func NewAgentLoop(cfg *config.Config, msgBus *bus.MessageBus, provider providers
 
 	sessionsManager := session.NewSessionManager(filepath.Join(workspace, "sessions"))
 
+	// Create state manager for atomic state persistence
+	stateManager := state.NewManager(workspace)
+
 	// Create context builder and set tools registry
 	contextBuilder := NewContextBuilder(workspace)
 	contextBuilder.SetToolsRegistry(toolsRegistry)
@@ -100,6 +105,7 @@ func NewAgentLoop(cfg *config.Config, msgBus *bus.MessageBus, provider providers
 		contextWindow:  cfg.Agents.Defaults.MaxTokens, // Restore context window for summarization
 		maxIterations:  cfg.Agents.Defaults.MaxToolIterations,
 		sessions:       sessionsManager,
+		state:          stateManager,
 		contextBuilder: contextBuilder,
 		tools:          toolsRegistry,
 		summarizing:    sync.Map{},
@@ -145,6 +151,18 @@ func (al *AgentLoop) RegisterTool(tool tools.Tool) {
 	al.tools.Register(tool)
 }
 
+// RecordLastChannel records the last active channel for this workspace.
+// This uses the atomic state save mechanism to prevent data loss on crash.
+func (al *AgentLoop) RecordLastChannel(channel string) error {
+	return al.state.SetLastChannel(al.workspace, channel)
+}
+
+// RecordLastChatID records the last active chat ID for this workspace.
+// This uses the atomic state save mechanism to prevent data loss on crash.
+func (al *AgentLoop) RecordLastChatID(chatID string) error {
+	return al.state.SetLastChatID(al.workspace, chatID)
+}
+
 func (al *AgentLoop) ProcessDirect(ctx context.Context, content, sessionKey string) (string, error) {
 	return al.ProcessDirectWithChannel(ctx, content, sessionKey, "cli", "direct")
 }

pkg/agent/loop_test.go

@@ -0,0 +1,153 @@
+package agent
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/sipeed/picoclaw/pkg/bus"
+	"github.com/sipeed/picoclaw/pkg/config"
+	"github.com/sipeed/picoclaw/pkg/providers"
+)
+
+// mockProvider is a simple mock LLM provider for testing
+type mockProvider struct{}
+
+func (m *mockProvider) Chat(ctx context.Context, messages []providers.Message, tools []providers.ToolDefinition, model string, opts map[string]interface{}) (*providers.LLMResponse, error) {
+	return &providers.LLMResponse{
+		Content:  "Mock response",
+		ToolCalls: []providers.ToolCall{},
+	}, nil
+}
+
+func (m *mockProvider) GetDefaultModel() string {
+	return "mock-model"
+}
+
+func TestRecordLastChannel(t *testing.T) {
+	// Create temp workspace
+	tmpDir, err := os.MkdirTemp("", "agent-test-*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create test config
+	cfg := &config.Config{
+		Agents: config.AgentsConfig{
+			Defaults: config.AgentDefaults{
+				Workspace:         tmpDir,
+				Model:             "test-model",
+				MaxTokens:         4096,
+				MaxToolIterations: 10,
+			},
+		},
+	}
+
+	// Create agent loop
+	msgBus := bus.NewMessageBus()
+	provider := &mockProvider{}
+	al := NewAgentLoop(cfg, msgBus, provider)
+
+	// Test RecordLastChannel
+	testChannel := "test-channel"
+	err = al.RecordLastChannel(testChannel)
+	if err != nil {
+		t.Fatalf("RecordLastChannel failed: %v", err)
+	}
+
+	// Verify the channel was saved
+	lastChannel := al.state.GetLastChannel()
+	if lastChannel != testChannel {
+		t.Errorf("Expected channel '%s', got '%s'", testChannel, lastChannel)
+	}
+
+	// Verify persistence by creating a new agent loop
+	al2 := NewAgentLoop(cfg, msgBus, provider)
+	if al2.state.GetLastChannel() != testChannel {
+		t.Errorf("Expected persistent channel '%s', got '%s'", testChannel, al2.state.GetLastChannel())
+	}
+}
+
+func TestRecordLastChatID(t *testing.T) {
+	// Create temp workspace
+	tmpDir, err := os.MkdirTemp("", "agent-test-*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create test config
+	cfg := &config.Config{
+		Agents: config.AgentsConfig{
+			Defaults: config.AgentDefaults{
+				Workspace:         tmpDir,
+				Model:             "test-model",
+				MaxTokens:         4096,
+				MaxToolIterations: 10,
+			},
+		},
+	}
+
+	// Create agent loop
+	msgBus := bus.NewMessageBus()
+	provider := &mockProvider{}
+	al := NewAgentLoop(cfg, msgBus, provider)
+
+	// Test RecordLastChatID
+	testChatID := "test-chat-id-123"
+	err = al.RecordLastChatID(testChatID)
+	if err != nil {
+		t.Fatalf("RecordLastChatID failed: %v", err)
+	}
+
+	// Verify the chat ID was saved
+	lastChatID := al.state.GetLastChatID()
+	if lastChatID != testChatID {
+		t.Errorf("Expected chat ID '%s', got '%s'", testChatID, lastChatID)
+	}
+
+	// Verify persistence by creating a new agent loop
+	al2 := NewAgentLoop(cfg, msgBus, provider)
+	if al2.state.GetLastChatID() != testChatID {
+		t.Errorf("Expected persistent chat ID '%s', got '%s'", testChatID, al2.state.GetLastChatID())
+	}
+}
+
+func TestNewAgentLoop_StateInitialized(t *testing.T) {
+	// Create temp workspace
+	tmpDir, err := os.MkdirTemp("", "agent-test-*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create test config
+	cfg := &config.Config{
+		Agents: config.AgentsConfig{
+			Defaults: config.AgentDefaults{
+				Workspace:         tmpDir,
+				Model:             "test-model",
+				MaxTokens:         4096,
+				MaxToolIterations: 10,
+			},
+		},
+	}
+
+	// Create agent loop
+	msgBus := bus.NewMessageBus()
+	provider := &mockProvider{}
+	al := NewAgentLoop(cfg, msgBus, provider)
+
+	// Verify state manager is initialized
+	if al.state == nil {
+		t.Error("Expected state manager to be initialized")
+	}
+
+	// Verify state directory was created
+	stateDir := filepath.Join(tmpDir, "state")
+	if _, err := os.Stat(stateDir); os.IsNotExist(err) {
+		t.Error("Expected state directory to exist")
+	}
+}