//! Agent loop implementation

use std::sync::Arc;
use std::sync::Mutex;
use futures::StreamExt;
use tokio::sync::mpsc;
use zclaw_types::{AgentId, SessionId, Message, Result};

use crate::driver::{LlmDriver, CompletionRequest, ContentBlock};
use crate::stream::StreamChunk;
use crate::tool::{ToolRegistry, ToolContext, SkillExecutor};
use crate::tool::builtin::PathValidator;
use crate::loop_guard::{LoopGuard, LoopGuardResult};
use crate::growth::GrowthIntegration;
use crate::compaction::{self, CompactionConfig};
use crate::middleware::{self, MiddlewareChain};
use crate::prompt::{PromptBuilder, PromptContext};
use zclaw_memory::MemoryStore;

/// Agent loop runner
pub struct AgentLoop {
    agent_id: AgentId,
    driver: Arc<dyn LlmDriver>,
    tools: ToolRegistry,
    memory: Arc<MemoryStore>,
    loop_guard: Mutex<LoopGuard>,
    model: String,
    system_prompt: Option<String>,
    /// Custom agent personality for prompt assembly
    soul: Option<String>,
    max_tokens: u32,
    temperature: f32,
    skill_executor: Option<Arc<dyn SkillExecutor>>,
    path_validator: Option<PathValidator>,
    /// Growth system integration (optional)
    growth: Option<GrowthIntegration>,
    /// Compaction threshold in tokens (0 = disabled)
    compaction_threshold: usize,
    /// Compaction behavior configuration
    compaction_config: CompactionConfig,
    /// Optional middleware chain — when `Some`, cross-cutting logic is
    /// delegated to the chain instead of the inline code below.
    /// When `None`, the legacy inline path is used (100% backward compatible).
    middleware_chain: Option<MiddlewareChain>,
    /// Chat mode: extended thinking enabled
    thinking_enabled: bool,
    /// Chat mode: reasoning effort level
    reasoning_effort: Option<String>,
    /// Chat mode: plan mode
    plan_mode: bool,
}

impl AgentLoop {
    pub fn new(
        agent_id: AgentId,
        driver: Arc<dyn LlmDriver>,
        tools: ToolRegistry,
        memory: Arc<MemoryStore>,
    ) -> Self {
        Self {
            agent_id,
            driver,
            tools,
            memory,
            loop_guard: Mutex::new(LoopGuard::default()),
            model: String::new(), // Must be set via with_model()
            system_prompt: None,
            soul: None,
            max_tokens: 16384,
            temperature: 0.7,
            skill_executor: None,
            path_validator: None,
            growth: None,
            compaction_threshold: 0,
            compaction_config: CompactionConfig::default(),
            middleware_chain: None,
            thinking_enabled: false,
            reasoning_effort: None,
            plan_mode: false,
        }
    }

    /// Set the skill executor for tool execution
    pub fn with_skill_executor(mut self, executor: Arc<dyn SkillExecutor>) -> Self {
        self.skill_executor = Some(executor);
        self
    }

    /// Set the path validator for file system operations
    pub fn with_path_validator(mut self, validator: PathValidator) -> Self {
        self.path_validator = Some(validator);
        self
    }

    /// Set the model to use
    pub fn with_model(mut self, model: impl Into<String>) -> Self {
        self.model = model.into();
        self
    }

    /// Set the system prompt
    pub fn with_system_prompt(mut self, prompt: impl Into<String>) -> Self {
        self.system_prompt = Some(prompt.into());
        self
    }

    /// Set the agent personality (SOUL.md equivalent)
    pub fn with_soul(mut self, soul: impl Into<String>) -> Self {
        self.soul = Some(soul.into());
        self
    }

    /// Enable extended thinking/reasoning mode
    pub fn with_thinking_enabled(mut self, enabled: bool) -> Self {
        self.thinking_enabled = enabled;
        self
    }

    /// Set reasoning effort level (low/medium/high)
    pub fn with_reasoning_effort(mut self, effort: impl Into<String>) -> Self {
        self.reasoning_effort = Some(effort.into());
        self
    }

    /// Enable plan mode
    pub fn with_plan_mode(mut self, enabled: bool) -> Self {
        self.plan_mode = enabled;
        self
    }

    /// Set max tokens
    pub fn with_max_tokens(mut self, max_tokens: u32) -> Self {
        self.max_tokens = max_tokens;
        self
    }

    /// Set temperature
    pub fn with_temperature(mut self, temperature: f32) -> Self {
        self.temperature = temperature;
        self
    }

    /// Enable growth system integration
    pub fn with_growth(mut self, growth: GrowthIntegration) -> Self {
        self.growth = Some(growth);
        self
    }

    /// Set growth system (mutable)
    pub fn set_growth(&mut self, growth: GrowthIntegration) {
        self.growth = Some(growth);
    }

    /// Set compaction threshold in tokens (0 = disabled)
    ///
    /// When the estimated token count of conversation history exceeds this
    /// threshold, older messages are summarized into a single system message
    /// and only recent messages are sent to the LLM.
    pub fn with_compaction_threshold(mut self, threshold: usize) -> Self {
        self.compaction_threshold = threshold;
        self
    }

    /// Set compaction configuration (LLM mode, memory flushing, etc.)
    pub fn with_compaction_config(mut self, config: CompactionConfig) -> Self {
        self.compaction_config = config;
        self
    }

    /// Inject a middleware chain. When set, cross-cutting concerns (compaction,
    /// loop guard, token calibration, etc.) are delegated to the chain instead
    /// of the inline logic.
    pub fn with_middleware_chain(mut self, chain: MiddlewareChain) -> Self {
        self.middleware_chain = Some(chain);
        self
    }

    /// Get growth integration reference
    pub fn growth(&self) -> Option<&GrowthIntegration> {
        self.growth.as_ref()
    }

    /// Create tool context for tool execution
    fn create_tool_context(&self, session_id: SessionId) -> ToolContext {
        // If no path_validator is configured, create a default one with user home as workspace.
        // This allows file_read/file_write tools to work without explicit workspace config,
        // while still restricting access to the user's home directory for security.
        let path_validator = self.path_validator.clone().unwrap_or_else(|| {
            let home = std::env::var("USERPROFILE")
                .or_else(|_| std::env::var("HOME"))
                .unwrap_or_else(|_| ".".to_string());
            let home_path = std::path::PathBuf::from(&home);
            tracing::info!(
                "[AgentLoop] No path_validator configured, using user home as workspace: {}",
                home_path.display()
            );
            PathValidator::new().with_workspace(home_path)
        });

        let working_dir = path_validator.workspace_root()
            .map(|p| p.to_string_lossy().to_string());

        ToolContext {
            agent_id: self.agent_id.clone(),
            working_directory: working_dir,
            session_id: Some(session_id.to_string()),
            skill_executor: self.skill_executor.clone(),
            path_validator: Some(path_validator),
            event_sender: None,
        }
    }

    /// Execute a tool with the given input
    async fn execute_tool(&self, tool_name: &str, input: serde_json::Value, context: &ToolContext) -> Result<serde_json::Value> {
        let tool = self.tools.get(tool_name)
            .ok_or_else(|| zclaw_types::ZclawError::ToolError(format!("Unknown tool: {}", tool_name)))?;
        tool.execute(input, context).await
    }

    /// Run the agent loop with a single message
    /// Implements complete agent loop: LLM → Tool Call → Tool Result → LLM → Final Response
    pub async fn run(&self, session_id: SessionId, input: String) -> Result<AgentLoopResult> {
        // Add user message to session
        let user_message = Message::user(input.clone());
        self.memory.append_message(&session_id, &user_message).await?;

        // Get all messages for context
        let mut messages = self.memory.get_messages(&session_id).await?;

        let use_middleware = self.middleware_chain.is_some();

        // Apply compaction — skip inline path when middleware chain handles it
        if !use_middleware && self.compaction_threshold > 0 {
            let needs_async =
                self.compaction_config.use_llm || self.compaction_config.memory_flush_enabled;
            if needs_async {
                let outcome = compaction::maybe_compact_with_config(
                    messages,
                    self.compaction_threshold,
                    &self.compaction_config,
                    &self.agent_id,
                    &session_id,
                    Some(&self.driver),
                    self.growth.as_ref(),
                )
                .await;
                messages = outcome.messages;
            } else {
                messages = compaction::maybe_compact(messages, self.compaction_threshold);
            }
        }

        // Enhance system prompt — skip when middleware chain handles it
        let mut enhanced_prompt = if use_middleware {
            let prompt_ctx = PromptContext {
                base_prompt: self.system_prompt.clone(),
                soul: self.soul.clone(),
                thinking_enabled: self.thinking_enabled,
                plan_mode: self.plan_mode,
                tool_definitions: self.tools.definitions(),
                agent_name: None,
            };
            PromptBuilder::new().build(&prompt_ctx)
        } else if let Some(ref growth) = self.growth {
            let base = self.system_prompt.as_deref().unwrap_or("");
            growth.enhance_prompt(&self.agent_id, base, &input).await?
        } else {
            self.system_prompt.clone().unwrap_or_default()
        };

        // Run middleware before_completion hooks (compaction, memory inject, etc.)
        if let Some(ref chain) = self.middleware_chain {
            let mut mw_ctx = middleware::MiddlewareContext {
                agent_id: self.agent_id.clone(),
                session_id: session_id.clone(),
                user_input: input.clone(),
                system_prompt: enhanced_prompt.clone(),
                messages,
                response_content: Vec::new(),
                input_tokens: 0,
                output_tokens: 0,
            };
            match chain.run_before_completion(&mut mw_ctx).await? {
                middleware::MiddlewareDecision::Continue => {
                    messages = mw_ctx.messages;
                    enhanced_prompt = mw_ctx.system_prompt;
                }
                middleware::MiddlewareDecision::Stop(reason) => {
                    return Ok(AgentLoopResult {
                        response: reason,
                        input_tokens: 0,
                        output_tokens: 0,
                        iterations: 1,
                    });
                }
            }
        }

        let max_iterations = 10;
        let mut iterations = 0;
        let mut total_input_tokens = 0u32;
        let mut total_output_tokens = 0u32;

        let result = loop {
            iterations += 1;
            if iterations > max_iterations {
                // Save the state before returning
                let error_msg = "达到最大迭代次数，请简化请求";
                self.memory.append_message(&session_id, &Message::assistant(error_msg)).await?;
                break AgentLoopResult {
                    response: error_msg.to_string(),
                    input_tokens: total_input_tokens,
                    output_tokens: total_output_tokens,
                    iterations,
                };
            }

            // Build completion request
            let request = CompletionRequest {
                model: self.model.clone(),
                system: Some(enhanced_prompt.clone()),
                messages: messages.clone(),
                tools: self.tools.definitions(),
                max_tokens: Some(self.max_tokens),
                temperature: Some(self.temperature),
                stop: Vec::new(),
                stream: false,
                thinking_enabled: self.thinking_enabled,
                reasoning_effort: self.reasoning_effort.clone(),
                plan_mode: self.plan_mode,
            };

            // Call LLM
            let response = self.driver.complete(request).await?;
            total_input_tokens += response.input_tokens;
            total_output_tokens += response.output_tokens;

            // Calibrate token estimation on first iteration
            if iterations == 1 {
                compaction::update_calibration(
                    compaction::estimate_messages_tokens(&messages),
                    response.input_tokens,
                );
            }

            // Extract tool calls from response
            let tool_calls: Vec<(String, String, serde_json::Value)> = response.content.iter()
                .filter_map(|block| match block {
                    ContentBlock::ToolUse { id, name, input } => Some((id.clone(), name.clone(), input.clone())),
                    _ => None,
                })
                .collect();

            // Extract text and thinking separately
            let text_parts: Vec<String> = response.content.iter()
                .filter_map(|block| match block {
                    ContentBlock::Text { text } => Some(text.clone()),
                    _ => None,
                })
                .collect();
            let thinking_parts: Vec<String> = response.content.iter()
                .filter_map(|block| match block {
                    ContentBlock::Thinking { thinking } => Some(thinking.clone()),
                    _ => None,
                })
                .collect();
            let text_content = text_parts.join("\n");
            let thinking_content = if thinking_parts.is_empty() { None } else { Some(thinking_parts.join("")) };

            // If no tool calls, we have the final response
            if tool_calls.is_empty() {
                // Save final assistant message with thinking
                let msg = if let Some(thinking) = &thinking_content {
                    Message::assistant_with_thinking(&text_content, thinking)
                } else {
                    Message::assistant(&text_content)
                };
                self.memory.append_message(&session_id, &msg).await?;

                break AgentLoopResult {
                    response: text_content,
                    input_tokens: total_input_tokens,
                    output_tokens: total_output_tokens,
                    iterations,
                };
            }

            // There are tool calls - push assistant message with thinking before tool calls
            // (required by Kimi and other thinking-enabled APIs)
            let assistant_msg = if let Some(thinking) = &thinking_content {
                Message::assistant_with_thinking(&text_content, thinking)
            } else {
                Message::assistant(&text_content)
            };
            messages.push(assistant_msg);

            for (id, name, input) in &tool_calls {
                messages.push(Message::tool_use(id, zclaw_types::ToolId::new(name), input.clone()));
            }

            // Create tool context and execute all tools
            let tool_context = self.create_tool_context(session_id.clone());
            let mut circuit_breaker_triggered = false;
            let mut abort_result: Option<AgentLoopResult> = None;
            let mut clarification_result: Option<AgentLoopResult> = None;
            for (id, name, input) in tool_calls {
                // Check if loop was already aborted
                if abort_result.is_some() {
                    break;
                }
                // Check tool call safety — via middleware chain or inline loop guard
                if let Some(ref chain) = self.middleware_chain {
                    let mw_ctx_ref = middleware::MiddlewareContext {
                        agent_id: self.agent_id.clone(),
                        session_id: session_id.clone(),
                        user_input: input.to_string(),
                        system_prompt: enhanced_prompt.clone(),
                        messages: messages.clone(),
                        response_content: Vec::new(),
                        input_tokens: total_input_tokens,
                        output_tokens: total_output_tokens,
                    };
                    match chain.run_before_tool_call(&mw_ctx_ref, &name, &input).await? {
                        middleware::ToolCallDecision::Allow => {}
                        middleware::ToolCallDecision::Block(msg) => {
                            tracing::warn!("[AgentLoop] Tool '{}' blocked by middleware: {}", name, msg);
                            let error_output = serde_json::json!({ "error": msg });
                            messages.push(Message::tool_result(id, zclaw_types::ToolId::new(&name), error_output, true));
                            continue;
                        }
                        middleware::ToolCallDecision::ReplaceInput(new_input) => {
                            // Execute with replaced input
                            let tool_result = match self.execute_tool(&name, new_input, &tool_context).await {
                                Ok(result) => result,
                                Err(e) => serde_json::json!({ "error": e.to_string() }),
                            };
                            messages.push(Message::tool_result(id, zclaw_types::ToolId::new(&name), tool_result, false));
                            continue;
                        }
                        middleware::ToolCallDecision::AbortLoop(reason) => {
                            tracing::warn!("[AgentLoop] Loop aborted by middleware: {}", reason);
                            let msg = format!("{}\n已自动终止", reason);
                            self.memory.append_message(&session_id, &Message::assistant(&msg)).await?;
                            abort_result = Some(AgentLoopResult {
                                response: msg,
                                input_tokens: total_input_tokens,
                                output_tokens: total_output_tokens,
                                iterations,
                            });
                        }
                    }
                } else {
                    // Legacy inline path
                    let guard_result = self.loop_guard.lock().unwrap_or_else(|e| e.into_inner()).check(&name, &input);
                    match guard_result {
                        LoopGuardResult::CircuitBreaker => {
                            tracing::warn!("[AgentLoop] Circuit breaker triggered by tool '{}'", name);
                            circuit_breaker_triggered = true;
                            break;
                        }
                        LoopGuardResult::Blocked => {
                            tracing::warn!("[AgentLoop] Tool '{}' blocked by loop guard", name);
                            let error_output = serde_json::json!({ "error": "工具调用被循环防护拦截" });
                            messages.push(Message::tool_result(id, zclaw_types::ToolId::new(&name), error_output, true));
                            continue;
                        }
                        LoopGuardResult::Warn => {
                            tracing::warn!("[AgentLoop] Tool '{}' triggered loop guard warning", name);
                        }
                        LoopGuardResult::Allowed => {}
                    }
                }

                let tool_result = match self.execute_tool(&name, input, &tool_context).await {
                    Ok(result) => result,
                    Err(e) => serde_json::json!({ "error": e.to_string() }),
                };

                // Check if this is a clarification response — terminate loop immediately
                // so the LLM waits for user input instead of continuing to generate.
                if name == "ask_clarification"
                    && tool_result.get("status").and_then(|v| v.as_str()) == Some("clarification_needed")
                {
                    tracing::info!("[AgentLoop] Clarification requested, terminating loop");
                    let question = tool_result.get("question")
                        .and_then(|v| v.as_str())
                        .unwrap_or("需要更多信息")
                        .to_string();
                    messages.push(Message::tool_result(
                        id,
                        zclaw_types::ToolId::new(&name),
                        tool_result,
                        false,
                    ));
                    self.memory.append_message(&session_id, &Message::assistant(&question)).await?;
                    clarification_result = Some(AgentLoopResult {
                        response: question,
                        input_tokens: total_input_tokens,
                        output_tokens: total_output_tokens,
                        iterations,
                    });
                    break;
                }

                // Add tool result to messages
                messages.push(Message::tool_result(
                    id,
                    zclaw_types::ToolId::new(&name),
                    tool_result,
                    false, // is_error - we include errors in the result itself
                ));
            }

            // Continue the loop - LLM will process tool results and generate final response

            // If middleware aborted the loop, return immediately
            if let Some(result) = abort_result {
                break result;
            }

            // If clarification was requested, return immediately
            if let Some(result) = clarification_result {
                break result;
            }

            // If circuit breaker was triggered, terminate immediately
            if circuit_breaker_triggered {
                let msg = "检测到工具调用循环，已自动终止";
                self.memory.append_message(&session_id, &Message::assistant(msg)).await?;
                break AgentLoopResult {
                    response: msg.to_string(),
                    input_tokens: total_input_tokens,
                    output_tokens: total_output_tokens,
                    iterations,
                };
            }
        };

        // Post-completion processing — middleware chain or inline growth
        if let Some(ref chain) = self.middleware_chain {
            let mw_ctx = middleware::MiddlewareContext {
                agent_id: self.agent_id.clone(),
                session_id: session_id.clone(),
                user_input: input.clone(),
                system_prompt: enhanced_prompt.clone(),
                messages: self.memory.get_messages(&session_id).await.unwrap_or_default(),
                response_content: Vec::new(),
                input_tokens: total_input_tokens,
                output_tokens: total_output_tokens,
            };
            if let Err(e) = chain.run_after_completion(&mw_ctx).await {
                tracing::warn!("[AgentLoop] Middleware after_completion failed: {}", e);
            }
        } else if let Some(ref growth) = self.growth {
            // Legacy inline path
            if let Ok(all_messages) = self.memory.get_messages(&session_id).await {
                if let Err(e) = growth.process_conversation(&self.agent_id, &all_messages, session_id.clone()).await {
                    tracing::warn!("[AgentLoop] Growth processing failed: {}", e);
                }
            }
        }

        Ok(result)
    }

    /// Run the agent loop with streaming
    /// Implements complete agent loop with multi-turn tool calling support
    pub async fn run_streaming(
        &self,
        session_id: SessionId,
        input: String,
    ) -> Result<mpsc::Receiver<LoopEvent>> {
        let (tx, rx) = mpsc::channel(100);

        // Add user message to session
        let user_message = Message::user(input.clone());
        self.memory.append_message(&session_id, &user_message).await?;

        // Get all messages for context
        let mut messages = self.memory.get_messages(&session_id).await?;

        let use_middleware = self.middleware_chain.is_some();

        // Apply compaction — skip inline path when middleware chain handles it
        if !use_middleware && self.compaction_threshold > 0 {
            let needs_async =
                self.compaction_config.use_llm || self.compaction_config.memory_flush_enabled;
            if needs_async {
                let outcome = compaction::maybe_compact_with_config(
                    messages,
                    self.compaction_threshold,
                    &self.compaction_config,
                    &self.agent_id,
                    &session_id,
                    Some(&self.driver),
                    self.growth.as_ref(),
                )
                .await;
                messages = outcome.messages;
            } else {
                messages = compaction::maybe_compact(messages, self.compaction_threshold);
            }
        }

        // Enhance system prompt — skip when middleware chain handles it
        let mut enhanced_prompt = if use_middleware {
            let prompt_ctx = PromptContext {
                base_prompt: self.system_prompt.clone(),
                soul: self.soul.clone(),
                thinking_enabled: self.thinking_enabled,
                plan_mode: self.plan_mode,
                tool_definitions: self.tools.definitions(),
                agent_name: None,
            };
            PromptBuilder::new().build(&prompt_ctx)
        } else if let Some(ref growth) = self.growth {
            let base = self.system_prompt.as_deref().unwrap_or("");
            growth.enhance_prompt(&self.agent_id, base, &input).await?
        } else {
            self.system_prompt.clone().unwrap_or_default()
        };

        // Run middleware before_completion hooks (compaction, memory inject, etc.)
        if let Some(ref chain) = self.middleware_chain {
            let mut mw_ctx = middleware::MiddlewareContext {
                agent_id: self.agent_id.clone(),
                session_id: session_id.clone(),
                user_input: input.clone(),
                system_prompt: enhanced_prompt.clone(),
                messages,
                response_content: Vec::new(),
                input_tokens: 0,
                output_tokens: 0,
            };
            match chain.run_before_completion(&mut mw_ctx).await? {
                middleware::MiddlewareDecision::Continue => {
                    messages = mw_ctx.messages;
                    enhanced_prompt = mw_ctx.system_prompt;
                }
                middleware::MiddlewareDecision::Stop(reason) => {
                    let _ = tx.send(LoopEvent::Complete(AgentLoopResult {
                        response: reason,
                        input_tokens: 0,
                        output_tokens: 0,
                        iterations: 1,
                    })).await;
                    return Ok(rx);
                }
            }
        }

        // Clone necessary data for the async task
        let session_id_clone = session_id.clone();
        let memory = self.memory.clone();
        let driver = self.driver.clone();
        let tools = self.tools.clone();
        let loop_guard_clone = self.loop_guard.lock().unwrap_or_else(|e| e.into_inner()).clone();
        let middleware_chain = self.middleware_chain.clone();
        let skill_executor = self.skill_executor.clone();
        let path_validator = self.path_validator.clone();
        let agent_id = self.agent_id.clone();
        let model = self.model.clone();
        let max_tokens = self.max_tokens;
        let temperature = self.temperature;
        let thinking_enabled = self.thinking_enabled;
        let reasoning_effort = self.reasoning_effort.clone();
        let plan_mode = self.plan_mode;

        tokio::spawn(async move {
            let mut messages = messages;
            let loop_guard_clone = Mutex::new(loop_guard_clone);
            let max_iterations = 10;
            let mut iteration = 0;
            let mut total_input_tokens = 0u32;
            let mut total_output_tokens = 0u32;

            'outer: loop {
                iteration += 1;
                if iteration > max_iterations {
                    let _ = tx.send(LoopEvent::Error("达到最大迭代次数".to_string())).await;
                    break;
                }

                // Notify iteration start
                let _ = tx.send(LoopEvent::IterationStart {
                    iteration,
                    max_iterations,
                }).await;

                // Build completion request
                let request = CompletionRequest {
                    model: model.clone(),
                    system: Some(enhanced_prompt.clone()),
                    messages: messages.clone(),
                    tools: tools.definitions(),
                    max_tokens: Some(max_tokens),
                    temperature: Some(temperature),
                    stop: Vec::new(),
                    stream: true,
                    thinking_enabled,
                    reasoning_effort: reasoning_effort.clone(),
                    plan_mode,
                };

                let mut stream = driver.stream(request);
                let mut pending_tool_calls: Vec<(String, String, serde_json::Value)> = Vec::new();
                let mut iteration_text = String::new();
                let mut reasoning_text = String::new(); // Track reasoning separately for API requirement

                // Process stream chunks
                tracing::debug!("[AgentLoop] Starting to process stream chunks");
                let mut chunk_count: usize = 0;
                let mut text_delta_count: usize = 0;
                let mut thinking_delta_count: usize = 0;
                let mut stream_errored = false;
                let chunk_timeout = std::time::Duration::from_secs(60);

                loop {
                    match tokio::time::timeout(chunk_timeout, stream.next()).await {
                        Ok(Some(Ok(chunk))) => {
                            chunk_count += 1;
                            match &chunk {
                                StreamChunk::TextDelta { delta } => {
                                    text_delta_count += 1;
                                    tracing::debug!("[AgentLoop] TextDelta #{}: {} chars", text_delta_count, delta.len());
                                    iteration_text.push_str(delta);
                                    let _ = tx.send(LoopEvent::Delta(delta.clone())).await;
                                }
                                StreamChunk::ThinkingDelta { delta } => {
                                    thinking_delta_count += 1;
                                    tracing::debug!("[AgentLoop] ThinkingDelta #{}: {} chars", thinking_delta_count, delta.len());
                                    reasoning_text.push_str(delta);
                                    let _ = tx.send(LoopEvent::ThinkingDelta(delta.clone())).await;
                                }
                                StreamChunk::ToolUseStart { id, name } => {
                                    tracing::debug!("[AgentLoop] ToolUseStart: id={}, name={}", id, name);
                                    pending_tool_calls.push((id.clone(), name.clone(), serde_json::Value::Null));
                                }
                                StreamChunk::ToolUseDelta { id, delta } => {
                                    // Accumulate tool input delta (internal processing, not sent to user)
                                    if let Some(tool) = pending_tool_calls.iter_mut().find(|(tid, _, _)| tid == id) {
                                        // Try to accumulate JSON string
                                        match &mut tool.2 {
                                            serde_json::Value::String(s) => s.push_str(delta),
                                            serde_json::Value::Null => tool.2 = serde_json::Value::String(delta.clone()),
                                            _ => {}
                                        }
                                    }
                                }
                                StreamChunk::ToolUseEnd { id, input } => {
                                    tracing::debug!("[AgentLoop] ToolUseEnd: id={}, input={:?}", id, input);
                                    // Update with final parsed input and emit ToolStart event
                                    if let Some(tool) = pending_tool_calls.iter_mut().find(|(tid, _, _)| tid == id) {
                                        tool.2 = input.clone();
                                        let _ = tx.send(LoopEvent::ToolStart { name: tool.1.clone(), input: input.clone() }).await;
                                    }
                                }
                                StreamChunk::Complete { input_tokens: it, output_tokens: ot, .. } => {
                                    tracing::debug!("[AgentLoop] Stream complete: input_tokens={}, output_tokens={}", it, ot);
                                    total_input_tokens += *it;
                                    total_output_tokens += *ot;
                                    // Calibrate token estimation on first iteration
                                    if iteration == 1 {
                                        compaction::update_calibration(
                                            compaction::estimate_messages_tokens(&messages),
                                            *it,
                                        );
                                    }
                                }
                                StreamChunk::Error { message } => {
                                    tracing::error!("[AgentLoop] Stream error: {}", message);
                                    let _ = tx.send(LoopEvent::Error(message.clone())).await;
                                    stream_errored = true;
                                }
                            }
                        }
                        Ok(Some(Err(e))) => {
                            tracing::error!("[AgentLoop] Chunk error: {}", e);
                            let _ = tx.send(LoopEvent::Error(format!("LLM 响应错误: {}", e.to_string()))).await;
                            stream_errored = true;
                        }
                        Ok(None) => break, // Stream ended normally
                        Err(_) => {
                            tracing::error!("[AgentLoop] Stream chunk timeout ({}s)", chunk_timeout.as_secs());
                            let _ = tx.send(LoopEvent::Error("LLM 响应超时，请重试".to_string())).await;
                            stream_errored = true;
                        }
                    }
                    if stream_errored {
                        break;
                    }
                }
                tracing::info!("[AgentLoop] Stream ended: {} total chunks (text={}, thinking={}, tools={}), iteration_text={} chars",
                    chunk_count, text_delta_count, thinking_delta_count, pending_tool_calls.len(),
                    iteration_text.len());

                // Fallback: if model generated reasoning but no text content,
                // use reasoning as text response. This happens with some thinking models
                // (DeepSeek R1, QWQ) that put the answer in reasoning_content instead of content.
                // Safe now because: (1) context is clean (no stale user_profile/memory injection),
                // (2) max_tokens=16384 prevents truncation, (3) reasoning is about the correct topic.
                if iteration_text.is_empty() && !reasoning_text.is_empty() {
                    tracing::info!("[AgentLoop] Model generated {} chars of reasoning but no text — using reasoning as response",
                        reasoning_text.len());
                    let _ = tx.send(LoopEvent::Delta(reasoning_text.clone())).await;
                    iteration_text = reasoning_text.clone();
                } else if iteration_text.is_empty() {
                    tracing::warn!("[AgentLoop] No text content after {} chunks (thinking_delta={})",
                        chunk_count, thinking_delta_count);
                }

                // If no tool calls, we have the final response
                if pending_tool_calls.is_empty() {
                    tracing::info!("[AgentLoop] No tool calls, returning final response: {} chars (reasoning: {} chars)", iteration_text.len(), reasoning_text.len());
                    // Save final assistant message with reasoning
                    if let Err(e) = memory.append_message(&session_id_clone, &Message::assistant_with_thinking(
                        &iteration_text,
                        &reasoning_text,
                    )).await {
                        tracing::warn!("[AgentLoop] Failed to save final assistant message: {}", e);
                    }

                    let _ = tx.send(LoopEvent::Complete(AgentLoopResult {
                        response: iteration_text.clone(),
                        input_tokens: total_input_tokens,
                        output_tokens: total_output_tokens,
                        iterations: iteration,
                    })).await;

                    // Post-completion: middleware after_completion (memory extraction, etc.)
                    if let Some(ref chain) = middleware_chain {
                        let mw_ctx = middleware::MiddlewareContext {
                            agent_id: agent_id.clone(),
                            session_id: session_id_clone.clone(),
                            user_input: String::new(),
                            system_prompt: enhanced_prompt.clone(),
                            messages: memory.get_messages(&session_id_clone).await.unwrap_or_default(),
                            response_content: Vec::new(),
                            input_tokens: total_input_tokens,
                            output_tokens: total_output_tokens,
                        };
                        if let Err(e) = chain.run_after_completion(&mw_ctx).await {
                            tracing::warn!("[AgentLoop] Streaming middleware after_completion failed: {}", e);
                        }
                    }

                    break 'outer;
                }

                // Skip tool processing if stream errored or timed out
                if stream_errored {
                    tracing::debug!("[AgentLoop] Stream errored, skipping tool processing and breaking");
                    break 'outer;
                }

                tracing::debug!("[AgentLoop] Processing {} tool calls (reasoning: {} chars)", pending_tool_calls.len(), reasoning_text.len());

                // Push assistant message with reasoning before tool calls (required by Kimi and other thinking-enabled APIs)
                messages.push(Message::assistant_with_thinking(
                    &iteration_text,
                    &reasoning_text,
                ));

                // There are tool calls - add to message history
                for (id, name, input) in &pending_tool_calls {
                    tracing::debug!("[AgentLoop] Adding tool_use to history: id={}, name={}, input={:?}", id, name, input);
                    messages.push(Message::tool_use(id, zclaw_types::ToolId::new(name), input.clone()));
                }

                // Execute tools
                for (id, name, input) in pending_tool_calls {
                    tracing::debug!("[AgentLoop] Executing tool: name={}, input={:?}", name, input);

                    // Check tool call safety — via middleware chain or inline loop guard
                    if let Some(ref chain) = middleware_chain {
                        let mw_ctx = middleware::MiddlewareContext {
                            agent_id: agent_id.clone(),
                            session_id: session_id_clone.clone(),
                            user_input: input.to_string(),
                            system_prompt: enhanced_prompt.clone(),
                            messages: messages.clone(),
                            response_content: Vec::new(),
                            input_tokens: total_input_tokens,
                            output_tokens: total_output_tokens,
                        };
                        match chain.run_before_tool_call(&mw_ctx, &name, &input).await {
                            Ok(middleware::ToolCallDecision::Allow) => {}
                            Ok(middleware::ToolCallDecision::Block(msg)) => {
                                tracing::warn!("[AgentLoop] Tool '{}' blocked by middleware: {}", name, msg);
                                let error_output = serde_json::json!({ "error": msg });
                                let _ = tx.send(LoopEvent::ToolEnd { name: name.clone(), output: error_output.clone() }).await;
                                messages.push(Message::tool_result(id, zclaw_types::ToolId::new(&name), error_output, true));
                                continue;
                            }
                            Ok(middleware::ToolCallDecision::AbortLoop(reason)) => {
                                tracing::warn!("[AgentLoop] Loop aborted by middleware: {}", reason);
                                let _ = tx.send(LoopEvent::Error(reason)).await;
                                break 'outer;
                            }
                            Ok(middleware::ToolCallDecision::ReplaceInput(new_input)) => {
                                // Execute with replaced input (same path_validator logic below)
                                let pv = path_validator.clone().unwrap_or_else(|| {
                                    let home = std::env::var("USERPROFILE")
                                        .or_else(|_| std::env::var("HOME"))
                                        .unwrap_or_else(|_| ".".to_string());
                                    PathValidator::new().with_workspace(std::path::PathBuf::from(&home))
                                });
                                let working_dir = pv.workspace_root()
                                    .map(|p| p.to_string_lossy().to_string());
                                let tool_context = ToolContext {
                                    agent_id: agent_id.clone(),
                                    working_directory: working_dir,
                                    session_id: Some(session_id_clone.to_string()),
                                    skill_executor: skill_executor.clone(),
                                    path_validator: Some(pv),
                                    event_sender: Some(tx.clone()),
                                };
                                let (result, is_error) = if let Some(tool) = tools.get(&name) {
                                    match tool.execute(new_input, &tool_context).await {
                                        Ok(output) => {
                                            let _ = tx.send(LoopEvent::ToolEnd { name: name.clone(), output: output.clone() }).await;
                                            (output, false)
                                        }
                                        Err(e) => {
                                            let error_output = serde_json::json!({ "error": e.to_string() });
                                            let _ = tx.send(LoopEvent::ToolEnd { name: name.clone(), output: error_output.clone() }).await;
                                            (error_output, true)
                                        }
                                    }
                                } else {
                                    let error_output = serde_json::json!({ "error": format!("Unknown tool: {}", name) });
                                    let _ = tx.send(LoopEvent::ToolEnd { name: name.clone(), output: error_output.clone() }).await;
                                    (error_output, true)
                                };
                                messages.push(Message::tool_result(id, zclaw_types::ToolId::new(&name), result, is_error));
                                continue;
                            }
                            Err(e) => {
                                tracing::error!("[AgentLoop] Middleware error for tool '{}': {}", name, e);
                                let error_output = serde_json::json!({ "error": e.to_string() });
                                let _ = tx.send(LoopEvent::ToolEnd { name: name.clone(), output: error_output.clone() }).await;
                                messages.push(Message::tool_result(id, zclaw_types::ToolId::new(&name), error_output, true));
                                continue;
                            }
                        }
                    } else {
                        // Legacy inline loop guard path
                        let guard_result = loop_guard_clone.lock().unwrap_or_else(|e| e.into_inner()).check(&name, &input);
                        match guard_result {
                            LoopGuardResult::CircuitBreaker => {
                                let _ = tx.send(LoopEvent::Error("检测到工具调用循环，已自动终止".to_string())).await;
                                break 'outer;
                            }
                            LoopGuardResult::Blocked => {
                                tracing::warn!("[AgentLoop] Tool '{}' blocked by loop guard", name);
                                let error_output = serde_json::json!({ "error": "工具调用被循环防护拦截" });
                                let _ = tx.send(LoopEvent::ToolEnd { name: name.clone(), output: error_output.clone() }).await;
                                messages.push(Message::tool_result(id, zclaw_types::ToolId::new(&name), error_output, true));
                                continue;
                            }
                            LoopGuardResult::Warn => {
                                tracing::warn!("[AgentLoop] Tool '{}' triggered loop guard warning", name);
                            }
                            LoopGuardResult::Allowed => {}
                        }
                    }
                    // Use pre-resolved path_validator (already has default fallback from create_tool_context logic)
                    let pv = path_validator.clone().unwrap_or_else(|| {
                        let home = std::env::var("USERPROFILE")
                            .or_else(|_| std::env::var("HOME"))
                            .unwrap_or_else(|_| ".".to_string());
                        PathValidator::new().with_workspace(std::path::PathBuf::from(&home))
                    });
                    let working_dir = pv.workspace_root()
                        .map(|p| p.to_string_lossy().to_string());
                    let tool_context = ToolContext {
                        agent_id: agent_id.clone(),
                        working_directory: working_dir,
                        session_id: Some(session_id_clone.to_string()),
                        skill_executor: skill_executor.clone(),
                        path_validator: Some(pv),
                        event_sender: Some(tx.clone()),
                    };

                    let (result, is_error) = if let Some(tool) = tools.get(&name) {
                        tracing::debug!("[AgentLoop] Tool '{}' found, executing...", name);
                        match tool.execute(input.clone(), &tool_context).await {
                            Ok(output) => {
                                tracing::debug!("[AgentLoop] Tool '{}' executed successfully: {:?}", name, output);
                                let _ = tx.send(LoopEvent::ToolEnd { name: name.clone(), output: output.clone() }).await;
                                (output, false)
                            }
                            Err(e) => {
                                tracing::error!("[AgentLoop] Tool '{}' execution failed: {}", name, e);
                                let error_output = serde_json::json!({ "error": e.to_string() });
                                let _ = tx.send(LoopEvent::ToolEnd { name: name.clone(), output: error_output.clone() }).await;
                                (error_output, true)
                            }
                        }
                    } else {
                        tracing::error!("[AgentLoop] Tool '{}' not found in registry", name);
                        let error_output = serde_json::json!({ "error": format!("Unknown tool: {}", name) });
                        let _ = tx.send(LoopEvent::ToolEnd { name: name.clone(), output: error_output.clone() }).await;
                        (error_output, true)
                    };

                    // Check if this is a clarification response — break outer loop
                    if name == "ask_clarification"
                        && result.get("status").and_then(|v| v.as_str()) == Some("clarification_needed")
                    {
                        tracing::info!("[AgentLoop] Streaming: Clarification requested, terminating loop");
                        let question = result.get("question")
                            .and_then(|v| v.as_str())
                            .unwrap_or("需要更多信息")
                            .to_string();
                        messages.push(Message::tool_result(
                            id,
                            zclaw_types::ToolId::new(&name),
                            result,
                            is_error,
                        ));
                        // Send the question as final delta so the user sees it
                        let _ = tx.send(LoopEvent::Delta(question.clone())).await;
                        let _ = tx.send(LoopEvent::Complete(AgentLoopResult {
                            response: question.clone(),
                            input_tokens: total_input_tokens,
                            output_tokens: total_output_tokens,
                            iterations: iteration,
                        })).await;
                        if let Err(e) = memory.append_message(&session_id_clone, &Message::assistant(&question)).await {
                            tracing::warn!("[AgentLoop] Failed to save clarification message: {}", e);
                        }
                        break 'outer;
                    }

                    // Add tool result to message history
                    tracing::debug!("[AgentLoop] Adding tool_result to history: id={}, name={}, is_error={}", id, name, is_error);
                    messages.push(Message::tool_result(
                        id,
                        zclaw_types::ToolId::new(&name),
                        result,
                        is_error,
                    ));
                }

                tracing::debug!("[AgentLoop] Continuing to next iteration for LLM to process tool results");
                // Continue loop - next iteration will call LLM with tool results
            }
        });

        Ok(rx)
    }
}

/// Result of an agent loop execution
#[derive(Debug, Clone)]
pub struct AgentLoopResult {
    pub response: String,
    pub input_tokens: u32,
    pub output_tokens: u32,
    pub iterations: usize,
}

/// Events emitted during streaming
#[derive(Debug, Clone)]
pub enum LoopEvent {
    /// Text delta from LLM
    Delta(String),
    /// Thinking/reasoning delta from LLM (extended thinking)
    ThinkingDelta(String),
    /// Tool execution started
    ToolStart { name: String, input: serde_json::Value },
    /// Tool execution completed
    ToolEnd { name: String, output: serde_json::Value },
    /// Sub-agent task status update (started/running/completed/failed)
    SubtaskStatus {
        description: String,
        status: String,
        detail: Option<String>,
    },
    /// New iteration started (multi-turn tool calling)
    IterationStart { iteration: usize, max_iterations: usize },
    /// Loop completed with final result
    Complete(AgentLoopResult),
    /// Error occurred
    Error(String),
}