codetether-agent 4.0.0

//! Agent system
//!
//! Agents are the core execution units that orchestrate tools and LLM interactions.

pub mod builtin;

use crate::config::PermissionAction;
use crate::provider::{CompletionRequest, ContentPart, Message, Provider, Role};
use crate::session::Session;
use crate::swarm::{Actor, ActorStatus, Handler, SwarmMessage};
use crate::tool::{Tool, ToolRegistry, ToolResult};
use anyhow::Result;
use async_trait::async_trait;
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::sync::Arc;

/// Agent information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AgentInfo {
    pub name: String,
    pub description: Option<String>,
    pub mode: AgentMode,
    pub native: bool,
    pub hidden: bool,
    pub model: Option<String>,
    pub temperature: Option<f32>,
    pub top_p: Option<f32>,
    pub max_steps: Option<usize>,
}

#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "lowercase")]
pub enum AgentMode {
    Primary,
    Subagent,
    All,
}

/// Metadata for a registered tool
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ToolMetadata {
    pub name: String,
    pub description: String,
    pub parameters: serde_json::Value,
}

/// The main agent execution context
pub struct Agent {
    pub info: AgentInfo,
    pub provider: Arc<dyn Provider>,
    pub tools: ToolRegistry,
    pub permissions: HashMap<String, PermissionAction>,
    /// Tool metadata for registered tools
    pub metadata: HashMap<String, ToolMetadata>,
    system_prompt: String,
}

impl Agent {
    /// Create a new agent
    pub fn new(
        info: AgentInfo,
        provider: Arc<dyn Provider>,
        tools: ToolRegistry,
        system_prompt: String,
    ) -> Self {
        Self {
            info,
            provider,
            tools,
            permissions: HashMap::new(),
            metadata: HashMap::new(),
            system_prompt,
        }
    }

    /// Execute a prompt and return the response
    pub async fn execute(&self, session: &mut Session, prompt: &str) -> Result<AgentResponse> {
        // Add user message to session
        session.add_message(Message {
            role: Role::User,
            content: vec![ContentPart::Text {
                text: prompt.to_string(),
            }],
        });

        let mut steps = 0;
        let max_steps = self.info.max_steps.unwrap_or(100);

        loop {
            steps += 1;
            if steps > max_steps {
                anyhow::bail!("Exceeded maximum steps ({})", max_steps);
            }

            // Build the completion request
            let request = CompletionRequest {
                messages: self.build_messages(session),
                tools: self.tools.definitions(),
                model: self
                    .info
                    .model
                    .clone()
                    .unwrap_or_else(|| match self.provider.name() {
                        "zhipuai" | "zai" => "glm-5".to_string(),
                        "openrouter" => "z-ai/glm-5".to_string(),
                        _ => "glm-5".to_string(),
                    }),
                temperature: self.info.temperature,
                top_p: self.info.top_p,
                max_tokens: None,
                stop: vec![],
            };

            // Get completion from provider
            let response = self.provider.complete(request).await?;
            session.add_message(response.message.clone());

            // Check for tool calls
            let tool_calls: Vec<_> = response
                .message
                .content
                .iter()
                .filter_map(|p| match p {
                    ContentPart::ToolCall {
                        id,
                        name,
                        arguments,
                        ..
                    } => Some((id.clone(), name.clone(), arguments.clone())),
                    _ => None,
                })
                .collect();

            if tool_calls.is_empty() {
                // No tool calls, we're done
                let text = response
                    .message
                    .content
                    .iter()
                    .filter_map(|p| match p {
                        ContentPart::Text { text } => Some(text.clone()),
                        _ => None,
                    })
                    .collect::<Vec<_>>()
                    .join("\n");

                return Ok(AgentResponse {
                    text,
                    tool_uses: session.tool_uses.clone(),
                    usage: session.usage.clone(),
                });
            }

            // Execute tool calls
            for (id, name, arguments) in tool_calls {
                let result = self.execute_tool(&name, &arguments).await;

                session.tool_uses.push(ToolUse {
                    id: id.clone(),
                    name: name.clone(),
                    input: arguments.clone(),
                    output: result.output.clone(),
                    success: result.success,
                });

                session.add_message(Message {
                    role: Role::Tool,
                    content: vec![ContentPart::ToolResult {
                        tool_call_id: id,
                        content: result.output,
                    }],
                });
            }
        }
    }

    /// Build the full message list including system prompt
    fn build_messages(&self, session: &Session) -> Vec<Message> {
        let mut messages = vec![Message {
            role: Role::System,
            content: vec![ContentPart::Text {
                text: self.system_prompt.clone(),
            }],
        }];
        messages.extend(session.messages.clone());
        messages
    }

    /// Execute a single tool
    async fn execute_tool(&self, name: &str, arguments: &str) -> ToolResult {
        // Check permissions for this tool
        if let Some(permission) = self.permissions.get(name) {
            tracing::debug!(tool = name, permission = ?permission, "Checking tool permission");
            // Permission validation could be extended here
            // For now, we just log that a permission check occurred
        }

        match self.tools.get(name) {
            Some(tool) => {
                let args: serde_json::Value = match serde_json::from_str(arguments) {
                    Ok(v) => v,
                    Err(e) => {
                        return ToolResult {
                            output: format!("Failed to parse arguments: {}", e),
                            success: false,
                            metadata: HashMap::new(),
                        };
                    }
                };

                match tool.execute(args).await {
                    Ok(result) => result,
                    Err(e) => ToolResult {
                        output: format!("Tool execution failed: {}", e),
                        success: false,
                        metadata: HashMap::new(),
                    },
                }
            }
            None => {
                // Use the invalid tool handler for better error messages
                let available_tools = self.tools.list().iter().map(|s| s.to_string()).collect();
                let invalid_tool = crate::tool::invalid::InvalidTool::with_context(
                    name.to_string(),
                    available_tools,
                );
                let args = serde_json::json!({
                    "requested_tool": name,
                    "args": serde_json::from_str::<serde_json::Value>(arguments).unwrap_or(serde_json::json!({}))
                });
                match invalid_tool.execute(args).await {
                    Ok(result) => result,
                    Err(e) => ToolResult {
                        output: format!("Unknown tool: {}. Error: {}", name, e),
                        success: false,
                        metadata: HashMap::new(),
                    },
                }
            }
        }
    }

    /// Get a tool from the registry by name
    pub fn get_tool(&self, name: &str) -> Option<Arc<dyn Tool>> {
        self.tools.get(name)
    }

    /// Register a tool with the agent's tool registry
    pub fn register_tool(&mut self, tool: Arc<dyn Tool>) {
        self.tools.register(tool);
    }

    /// List all available tool IDs
    pub fn list_tools(&self) -> Vec<&str> {
        self.tools.list()
    }

    /// Check if a tool is available
    pub fn has_tool(&self, name: &str) -> bool {
        self.tools.get(name).is_some()
    }
}

/// Actor implementation for Agent - enables swarm participation
#[async_trait]
impl Actor for Agent {
    fn actor_id(&self) -> &str {
        &self.info.name
    }

    fn actor_status(&self) -> ActorStatus {
        // Agent is always ready to process messages
        ActorStatus::Ready
    }

    async fn initialize(&mut self) -> Result<()> {
        // Agent initialization is handled during construction
        // Additional async initialization can be added here
        tracing::info!(
            "Agent '{}' initialized for swarm participation",
            self.info.name
        );
        Ok(())
    }

    async fn shutdown(&mut self) -> Result<()> {
        tracing::info!("Agent '{}' shutting down", self.info.name);
        Ok(())
    }
}

/// Handler implementation for SwarmMessage - enables message processing
#[async_trait]
impl Handler<SwarmMessage> for Agent {
    type Response = SwarmMessage;

    async fn handle(&mut self, message: SwarmMessage) -> Result<Self::Response> {
        match message {
            SwarmMessage::ExecuteTask {
                task_id,
                instruction,
            } => {
                // Create a new session for this task
                let mut session = Session::new().await?;

                // Execute the task
                match self.execute(&mut session, &instruction).await {
                    Ok(response) => Ok(SwarmMessage::TaskCompleted {
                        task_id,
                        result: response.text,
                    }),
                    Err(e) => Ok(SwarmMessage::TaskFailed {
                        task_id,
                        error: e.to_string(),
                    }),
                }
            }
            SwarmMessage::ToolRequest { tool_id, arguments } => {
                // Execute the requested tool
                let result = if let Some(tool) = self.get_tool(&tool_id) {
                    match tool.execute(arguments).await {
                        Ok(r) => r,
                        Err(e) => ToolResult::error(format!("Tool execution failed: {}", e)),
                    }
                } else {
                    // Use the invalid tool handler for better error messages
                    let available_tools = self.tools.list().iter().map(|s| s.to_string()).collect();
                    let invalid_tool = crate::tool::invalid::InvalidTool::with_context(
                        tool_id.clone(),
                        available_tools,
                    );
                    let args = serde_json::json!({
                        "requested_tool": tool_id,
                        "args": arguments
                    });
                    match invalid_tool.execute(args).await {
                        Ok(r) => r,
                        Err(e) => ToolResult::error(format!("Tool '{}' not found: {}", tool_id, e)),
                    }
                };

                Ok(SwarmMessage::ToolResponse { tool_id, result })
            }
            _ => {
                // Other message types are not handled directly by the agent
                Ok(SwarmMessage::TaskFailed {
                    task_id: "unknown".to_string(),
                    error: "Unsupported message type".to_string(),
                })
            }
        }
    }
}

/// Response from agent execution
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AgentResponse {
    pub text: String,
    pub tool_uses: Vec<ToolUse>,
    pub usage: crate::provider::Usage,
}

/// Record of a tool use
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ToolUse {
    pub id: String,
    pub name: String,
    pub input: String,
    pub output: String,
    pub success: bool,
}

/// Registry of available agents
pub struct AgentRegistry {
    agents: HashMap<String, AgentInfo>,
}

impl AgentRegistry {
    #[allow(dead_code)]
    pub fn new() -> Self {
        Self {
            agents: HashMap::new(),
        }
    }

    /// Register a new agent
    pub fn register(&mut self, info: AgentInfo) {
        self.agents.insert(info.name.clone(), info);
    }

    /// Get agent info by name
    #[allow(dead_code)]
    pub fn get(&self, name: &str) -> Option<&AgentInfo> {
        self.agents.get(name)
    }

    /// List all agents
    pub fn list(&self) -> Vec<&AgentInfo> {
        self.agents.values().collect()
    }

    /// List primary agents (visible in UI)
    #[allow(dead_code)]
    pub fn list_primary(&self) -> Vec<&AgentInfo> {
        self.agents
            .values()
            .filter(|a| a.mode == AgentMode::Primary && !a.hidden)
            .collect()
    }

    /// Initialize with builtin agents
    pub fn with_builtins() -> Self {
        let mut registry = Self::new();

        registry.register(builtin::build_agent());
        registry.register(builtin::plan_agent());
        registry.register(builtin::explore_agent());

        registry
    }
}

impl Default for AgentRegistry {
    fn default() -> Self {
        Self::with_builtins()
    }
}