feat: handle PermissionDenied hook event and drive Permission character state (closes #256)

src-tauri/src/types.rs

@@ -344,6 +344,16 @@ pub struct TaskCreatedEvent {
     pub conversation_id: Option<String>,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct PermissionDeniedEvent {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tool_name: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub reason: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub conversation_id: Option<String>,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct AgentStartEvent {
     pub tool_use_id: String,
@@ -860,4 +870,44 @@ mod tests {
         assert!(!serialized.contains("parent_tool_use_id"));
         assert!(!serialized.contains("conversation_id"));
     }
+
+    #[test]
+    fn test_permission_denied_event_serialization() {
+        let event = PermissionDeniedEvent {
+            tool_name: Some("Bash".to_string()),
+            reason: Some("Tool not in allow list".to_string()),
+            conversation_id: Some("conv-abc".to_string()),
+        };
+
+        let serialized = serde_json::to_string(&event).unwrap();
+        assert!(serialized.contains("\"tool_name\":\"Bash\""));
+        assert!(serialized.contains("\"reason\":\"Tool not in allow list\""));
+        assert!(serialized.contains("\"conversation_id\":\"conv-abc\""));
+    }
+
+    #[test]
+    fn test_permission_denied_event_omits_none_fields() {
+        let event = PermissionDeniedEvent {
+            tool_name: None,
+            reason: None,
+            conversation_id: None,
+        };
+
+        let serialized = serde_json::to_string(&event).unwrap();
+        assert_eq!(serialized, "{}");
+    }
+
+    #[test]
+    fn test_permission_denied_event_partial_fields() {
+        let event = PermissionDeniedEvent {
+            tool_name: Some("Edit".to_string()),
+            reason: None,
+            conversation_id: None,
+        };
+
+        let serialized = serde_json::to_string(&event).unwrap();
+        assert!(serialized.contains("\"tool_name\":\"Edit\""));
+        assert!(!serialized.contains("reason"));
+        assert!(!serialized.contains("conversation_id"));
+    }
 }

src-tauri/src/wsl_bridge.rs

@@ -16,10 +16,10 @@ use crate::stats::{calculate_cost, StatsUpdateEvent, UsageStats};
 use crate::types::{
     AgentEndEvent, AgentStartEvent, CharacterState, ClaudeMessage, ConnectionEvent,
     ConnectionStatus, ContentBlock, CwdChangedEvent, ElicitationEvent, ElicitationResultEvent,
-    FileChangedEvent, MessageCost, OutputEvent, PermissionPromptEvent, PermissionPromptEventItem,
-    PostCompactEvent, QuestionOption, SessionEvent, StateChangeEvent, StopFailureEvent,
-    TaskCreatedEvent, TodoItem, TodoUpdateEvent, UserQuestionEvent, WorkingDirectoryEvent,
-    WorktreeEvent, WorktreeInfo,
+    FileChangedEvent, MessageCost, OutputEvent, PermissionDeniedEvent, PermissionPromptEvent,
+    PermissionPromptEventItem, PostCompactEvent, QuestionOption, SessionEvent, StateChangeEvent,
+    StopFailureEvent, TaskCreatedEvent, TodoItem, TodoUpdateEvent, UserQuestionEvent,
+    WorkingDirectoryEvent, WorktreeEvent, WorktreeInfo,
 };
 use parking_lot::RwLock;
 use std::cell::RefCell;
@@ -1082,6 +1082,7 @@ fn handle_stderr(
                 let is_cwd_changed = line.contains("[CwdChanged Hook]");
                 let is_file_changed = line.contains("[FileChanged Hook]");
                 let is_task_created = line.contains("[TaskCreated Hook]");
+                let is_permission_denied = line.contains("[PermissionDenied Hook]");
 
                 let line_type = if is_worktree_create || is_worktree_remove {
                     "worktree"
@@ -1099,6 +1100,8 @@ fn handle_stderr(
                     "file-changed"
                 } else if is_task_created {
                     "task-created"
+                } else if is_permission_denied {
+                    "permission-denied"
                 } else {
                     "error"
                 };
@@ -1316,6 +1319,45 @@ fn handle_stderr(
                             parent_tool_use_id: None,
                         },
                     );
+                } else if is_permission_denied {
+                    let data = parse_permission_denied_hook(&line);
+                    let friendly_content = match (data.tool_name.as_deref(), data.reason.as_deref()) {
+                        (Some(tool), Some(reason)) => {
+                            format!("Permission denied for {}: {}", tool, reason)
+                        }
+                        (Some(tool), None) => format!("Permission denied for {}", tool),
+                        _ => "Permission denied".to_string(),
+                    };
+
+                    let _ = app.emit(
+                        "claude:state-change",
+                        StateChangeEvent {
+                            state: CharacterState::Permission,
+                            tool_name: data.tool_name.clone(),
+                            conversation_id: conversation_id.clone(),
+                        },
+                    );
+
+                    let _ = app.emit(
+                        "claude:permission-denied",
+                        PermissionDeniedEvent {
+                            tool_name: data.tool_name,
+                            reason: data.reason,
+                            conversation_id: conversation_id.clone(),
+                        },
+                    );
+
+                    let _ = app.emit(
+                        "claude:output",
+                        OutputEvent {
+                            line_type: "permission-denied".to_string(),
+                            content: friendly_content,
+                            tool_name: None,
+                            conversation_id: conversation_id.clone(),
+                            cost: None,
+                            parent_tool_use_id: None,
+                        },
+                    );
                 } else {
                     let _ = app.emit(
                         "claude:output",
@@ -1591,6 +1633,23 @@ fn parse_task_created_hook(line: &str) -> TaskCreatedData {
     TaskCreatedData { task_id, description, parent_tool_use_id }
 }
 
+#[derive(Debug)]
+struct PermissionDeniedData {
+    tool_name: Option<String>,
+    reason: Option<String>,
+}
+
+fn parse_permission_denied_hook(line: &str) -> PermissionDeniedData {
+    let tool_name = extract_quoted_value(line, "tool_name")
+        .or_else(|| extract_quoted_value(line, "tool"))
+        .or_else(|| extract_debug_string_value(line, "tool_name"));
+
+    let reason = extract_quoted_value(line, "reason")
+        .or_else(|| extract_quoted_value(line, "message"));
+
+    PermissionDeniedData { tool_name, reason }
+}
+
 /// Extracts a double-quoted string value from a `key="value"` pair in a hook line.
 /// Handles escape sequences within the quoted value.
 fn extract_quoted_value(line: &str, key: &str) -> Option<String> {
@@ -3831,6 +3890,38 @@ mod tests {
         assert_eq!(data.parent_tool_use_id, None);
     }
 
+    #[test]
+    fn test_parse_permission_denied_hook_with_all_fields() {
+        let line = r#"[PermissionDenied Hook] tool_name="Bash", reason="Tool not in allow list""#;
+        let data = parse_permission_denied_hook(line);
+        assert_eq!(data.tool_name, Some("Bash".to_string()));
+        assert_eq!(data.reason, Some("Tool not in allow list".to_string()));
+    }
+
+    #[test]
+    fn test_parse_permission_denied_hook_tool_only() {
+        let line = r#"[PermissionDenied Hook] tool_name="Edit""#;
+        let data = parse_permission_denied_hook(line);
+        assert_eq!(data.tool_name, Some("Edit".to_string()));
+        assert_eq!(data.reason, None);
+    }
+
+    #[test]
+    fn test_parse_permission_denied_hook_tool_key_alias() {
+        let line = r#"[PermissionDenied Hook] tool="Write", reason="Workspace not trusted""#;
+        let data = parse_permission_denied_hook(line);
+        assert_eq!(data.tool_name, Some("Write".to_string()));
+        assert_eq!(data.reason, Some("Workspace not trusted".to_string()));
+    }
+
+    #[test]
+    fn test_parse_permission_denied_hook_empty_line() {
+        let line = "[PermissionDenied Hook]";
+        let data = parse_permission_denied_hook(line);
+        assert_eq!(data.tool_name, None);
+        assert_eq!(data.reason, None);
+    }
+
     #[test]
     fn test_build_stop_failure_message_no_fields() {
         let data = StopFailureData {