| 1 | //! Approval + user-input handshake for the agent loop. |
| 2 | //! |
| 3 | //! Extracted from `core/engine.rs` (P1.3). The agent loop blocks on these |
| 4 | //! two futures whenever a tool requires explicit approval (`await_tool_approval`) |
| 5 | //! or whenever a tool requests live user input (`await_user_input`). Channels |
| 6 | //! and engine state stay private to the parent module. |
| 7 | |
| 8 | use std::time::Duration; |
| 9 | |
| 10 | use crate::core::events::Event; |
| 11 | use crate::tools::spec::ToolError; |
| 12 | use crate::tools::user_input::{UserInputRequest, UserInputResponse}; |
| 13 | |
| 14 | const USER_INPUT_TIMEOUT: Duration = Duration::from_secs(300); |
| 15 | |
| 16 | use super::Engine; |
| 17 | |
| 18 | #[derive(Debug, Clone)] |
| 19 | pub(super) enum ApprovalDecision { |
| 20 | Approved { |
| 21 | id: String, |
| 22 | }, |
| 23 | Denied { |
| 24 | id: String, |
| 25 | }, |
| 26 | /// Retry a tool with an elevated sandbox policy. |
| 27 | RetryWithPolicy { |
| 28 | id: String, |
| 29 | policy: crate::sandbox::SandboxPolicy, |
| 30 | }, |
| 31 | } |
| 32 | |
| 33 | #[derive(Debug, Clone)] |
| 34 | pub(super) enum UserInputDecision { |
| 35 | Submitted { |
| 36 | id: String, |
| 37 | response: UserInputResponse, |
| 38 | }, |
| 39 | Cancelled { |
| 40 | id: String, |
| 41 | }, |
| 42 | } |
| 43 | |
| 44 | /// Result of awaiting tool approval from the user. |
| 45 | #[derive(Debug)] |
| 46 | pub(super) enum ApprovalResult { |
| 47 | /// User approved the tool execution. |
| 48 | Approved, |
| 49 | /// User denied the tool execution. |
| 50 | Denied, |
| 51 | /// User requested retry with an elevated sandbox policy. |
| 52 | RetryWithPolicy(crate::sandbox::SandboxPolicy), |
| 53 | } |
| 54 | |
| 55 | impl Engine { |
| 56 | /// Format a cancellation suffix when the engine knows the cause. |
| 57 | /// Some internal cancellation paths still use the raw token while |
| 58 | /// #1541 is open; those keep the legacy message without a guessed |
| 59 | /// reason. |
| 60 | fn cancel_reason_suffix(&self) -> String { |
| 61 | let reason = match self.cancel_reason.lock() { |
| 62 | Ok(slot) => *slot, |
| 63 | Err(poisoned) => *poisoned.into_inner(), |
| 64 | }; |
| 65 | match reason { |
| 66 | Some(reason) => format!(" (reason: {})", reason.describe()), |
| 67 | None => String::new(), |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | pub(super) async fn await_tool_approval( |
| 72 | &mut self, |
| 73 | tool_id: &str, |
| 74 | ) -> Result<ApprovalResult, ToolError> { |
| 75 | loop { |
| 76 | tokio::select! { |
| 77 | _ = self.cancel_token.cancelled() => { |
| 78 | let suffix = self.cancel_reason_suffix(); |
| 79 | return Err(ToolError::cancelled( |
| 80 | format!("Request cancelled while awaiting approval{suffix}"), |
| 81 | )); |
| 82 | } |
| 83 | decision = self.rx_approval.recv() => { |
| 84 | let Some(decision) = decision else { |
| 85 | return Err(ToolError::execution_failed( |
| 86 | "Approval channel closed — engine is shutting down. \ |
| 87 | The approval modal can no longer reach the engine; \ |
| 88 | this is typically a teardown race, not a user action." |
| 89 | .to_string(), |
| 90 | )); |
| 91 | }; |
| 92 | match decision { |
| 93 | ApprovalDecision::Approved { id } if id == tool_id => { |
| 94 | return Ok(ApprovalResult::Approved); |
| 95 | } |
| 96 | ApprovalDecision::Denied { id } if id == tool_id => { |
| 97 | return Ok(ApprovalResult::Denied); |
| 98 | } |
| 99 | ApprovalDecision::RetryWithPolicy { id, policy } if id == tool_id => { |
| 100 | return Ok(ApprovalResult::RetryWithPolicy(policy)); |
| 101 | } |
| 102 | _ => continue, |
| 103 | } |
| 104 | } |
| 105 | } |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | pub(super) async fn await_user_input( |
| 110 | &mut self, |
| 111 | tool_id: &str, |
| 112 | request: UserInputRequest, |
| 113 | ) -> Result<UserInputResponse, ToolError> { |
| 114 | let _ = self |
| 115 | .tx_event |
| 116 | .send(Event::UserInputRequired { |
| 117 | id: tool_id.to_string(), |
| 118 | request, |
| 119 | }) |
| 120 | .await; |
| 121 | |
| 122 | loop { |
| 123 | tokio::select! { |
| 124 | _ = self.cancel_token.cancelled() => { |
| 125 | let suffix = self.cancel_reason_suffix(); |
| 126 | return Err(ToolError::cancelled( |
| 127 | format!("Request cancelled while awaiting user input{suffix}"), |
| 128 | )); |
| 129 | } |
| 130 | result = tokio::time::timeout(USER_INPUT_TIMEOUT, self.rx_user_input.recv()) => { |
| 131 | match result { |
| 132 | Ok(Some(decision)) => { |
| 133 | match decision { |
| 134 | UserInputDecision::Submitted { id, response } if id == tool_id => { |
| 135 | return Ok(response); |
| 136 | } |
| 137 | UserInputDecision::Cancelled { id } if id == tool_id => { |
| 138 | return Err(ToolError::cancelled( |
| 139 | "User input cancelled".to_string(), |
| 140 | )); |
| 141 | } |
| 142 | _ => continue, |
| 143 | } |
| 144 | } |
| 145 | Ok(None) => { |
| 146 | return Err(ToolError::execution_failed( |
| 147 | "User input channel closed".to_string(), |
| 148 | )); |
| 149 | } |
| 150 | Err(_) => { |
| 151 | let _ = self |
| 152 | .tx_event |
| 153 | .send(Event::Status { |
| 154 | message: format!( |
| 155 | "User input timed out after {}s", |
| 156 | USER_INPUT_TIMEOUT.as_secs() |
| 157 | ), |
| 158 | }) |
| 159 | .await; |
| 160 | return Err(ToolError::Timeout { |
| 161 | seconds: USER_INPUT_TIMEOUT.as_secs(), |
| 162 | }); |
| 163 | } |
| 164 | } |
| 165 | } |
| 166 | } |
| 167 | } |
| 168 | } |
| 169 | } |
| 170 |