// PicoClaw - Ultra-lightweight personal AI agent
// Inspired by and based on nanobot: https://github.com/HKUDS/nanobot
// License: MIT
//
// Copyright (c) 2026 PicoClaw contributors

package agent

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"strings"
	"sync"
	"sync/atomic"
	"time"
	"unicode/utf8"

	"github.com/sipeed/picoclaw/pkg/bus"
	"github.com/sipeed/picoclaw/pkg/channels"
	"github.com/sipeed/picoclaw/pkg/config"
	"github.com/sipeed/picoclaw/pkg/constants"
	"github.com/sipeed/picoclaw/pkg/logger"
	"github.com/sipeed/picoclaw/pkg/metrics"
	"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"
)

type ToolCacheEntry struct {
	Result    *tools.ToolResult
	ExpiresAt time.Time
}

type AgentLoop struct {
	bus            *bus.MessageBus
	provider       providers.LLMProvider
	workspace      string
	model          string
	fallbackModels []string
	contextWindow  int // Maximum context window size in tokens
	maxIterations  int
	sessions       *session.SessionManager
	state          *state.Manager
	contextBuilder *ContextBuilder
	tools          *tools.ToolRegistry
	running        atomic.Bool
	summarizing    sync.Map // Tracks which sessions are currently being summarized
	channelManager *channels.Manager
	config         *config.Config
	cache          map[string]ToolCacheEntry
	cacheMutex     sync.RWMutex
}

// processOptions configures how a message is processed
type processOptions struct {
	SessionKey      string // Session identifier for history/context
	Channel         string // Target channel for tool execution
	ChatID          string // Target chat ID for tool execution
	UserMessage     string // User message content (may include prefix)
	DefaultResponse string // Response when LLM returns empty
	EnableSummary   bool   // Whether to trigger summarization
	SendResponse    bool   // Whether to send response via bus
	NoHistory       bool   // If true, don't load session history (for heartbeat)
	Media           []string // Attached media file paths
	MaxIterations   int    // Maximum iterations for this specific request
}

// createToolRegistry creates a tool registry with common tools.
// This is shared between main agent and subagents.
func createToolRegistry(workspace string, restrict bool, cfg *config.Config, msgBus *bus.MessageBus) *tools.ToolRegistry {
	registry := tools.NewToolRegistry()

	// File system tools
	registry.Register(tools.NewReadFileTool(workspace, restrict))
	registry.Register(tools.NewWriteFileTool(workspace, restrict))
	registry.Register(tools.NewListDirTool(workspace, restrict))
	registry.Register(tools.NewEditFileTool(workspace, restrict))
	registry.Register(tools.NewAppendFileTool(workspace, restrict))

	// Shell execution
	registry.Register(tools.NewExecTool(workspace, restrict, cfg.Tools.ResourceLimits))

	if searchTool := tools.NewWebSearchTool(tools.WebSearchToolOptions{
		BraveAPIKey:          cfg.Tools.Web.Brave.APIKey,
		BraveMaxResults:      cfg.Tools.Web.Brave.MaxResults,
		BraveEnabled:         cfg.Tools.Web.Brave.Enabled,
		DuckDuckGoMaxResults: cfg.Tools.Web.DuckDuckGo.MaxResults,
		DuckDuckGoEnabled:    cfg.Tools.Web.DuckDuckGo.Enabled,
	}); searchTool != nil {
		registry.Register(searchTool)
	}
	registry.Register(tools.NewWebFetchTool(50000))

	// Hardware tools (I2C, SPI) - Linux only, returns error on other platforms
	registry.Register(tools.NewI2CTool())
	registry.Register(tools.NewSPITool())

	// Message tool - available to both agent and subagent
	// Subagent uses it to communicate directly with user
	messageTool := tools.NewMessageTool()
	messageTool.SetSendCallback(func(channel, chatID, content string) error {
		var audioPath string

		// Check for [NO_VOICE] prefix to skip TTS
		if strings.HasPrefix(strings.TrimSpace(content), "[NO_VOICE]") {
			content = strings.TrimSpace(strings.TrimPrefix(strings.TrimSpace(content), "[NO_VOICE]"))
		} else {
			// Try to generate audio
			if path, err := generateTTS(workspace, content); err == nil {
				audioPath = path
			} else {
				logger.DebugCF("agent", "TTS generation skipped/failed (message tool)", map[string]interface{}{
					"error": err.Error(),
				})
			}
		}

		msgBus.PublishOutbound(bus.OutboundMessage{
			Channel:   channel,
			ChatID:    chatID,
			Content:   content,
			AudioPath: audioPath,
		})
		return nil
	})
	registry.Register(messageTool)

	return registry
}

func NewAgentLoop(cfg *config.Config, msgBus *bus.MessageBus, provider providers.LLMProvider) *AgentLoop {
	workspace := cfg.WorkspacePath()
	os.MkdirAll(workspace, 0755)

	restrict := cfg.Agents.Defaults.RestrictToWorkspace

	// Create tool registry for main agent
	toolsRegistry := createToolRegistry(workspace, restrict, cfg, msgBus)

	// Create subagent manager with its own tool registry
	subagentManager := tools.NewSubagentManager(provider, cfg.Agents.Defaults.Model, workspace, msgBus)
	subagentTools := createToolRegistry(workspace, restrict, cfg, msgBus)
	// Subagent doesn't need spawn/subagent tools to avoid recursion
	subagentManager.SetTools(subagentTools)

	// Register spawn tool (for main agent)
	spawnTool := tools.NewSpawnTool(subagentManager)
	toolsRegistry.Register(spawnTool)

	// Register subagent tool (synchronous execution)
	subagentTool := tools.NewSubagentTool(subagentManager)
	toolsRegistry.Register(subagentTool)

	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)

	return &AgentLoop{
		config:         cfg,
		bus:            msgBus,
		provider:       provider,
		workspace:      workspace,
		model:          cfg.Agents.Defaults.Model,
		fallbackModels: cfg.Agents.Defaults.FallbackModels,
		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{},
		cache:          make(map[string]ToolCacheEntry),
	}
}

func generateTTS(workspace, text string) (string, error) {
	// Clean text for TTS (remove markdown symbols)
	// 1. Remove code blocks
	reCode := regexp.MustCompile("```[\\s\\S]*?```")
	cleanText := reCode.ReplaceAllString(text, "code block")

	// 2. Remove inline code
	reInline := regexp.MustCompile("`[^`]*`")
	cleanText = reInline.ReplaceAllString(cleanText, "code")

	// 3. Remove links [text](url) -> text
	reLink := regexp.MustCompile(`\[([^\]]+)\]\([^\)]+\)`)
	cleanText = reLink.ReplaceAllString(cleanText, "$1")

	// 4. Remove bold/italic/header markers (*, _, #)
	reSymbols := regexp.MustCompile(`[\*\_#]`)
	cleanText = reSymbols.ReplaceAllString(cleanText, "")

	// Search in workspace/skills and system skills
	skillPaths := []string{
		filepath.Join(workspace, "skills", "voice-tts"),
		"/picoclaw/skills/voice-tts",
		"workspace/skills/voice-tts",
	}

	var scriptPath string
	for _, p := range skillPaths {
		sp := filepath.Join(p, "scripts", "speak.py")
		if _, err := os.Stat(sp); err == nil {
			scriptPath = sp
			break
		}
	}

	if scriptPath == "" {
		return "", fmt.Errorf("voice-tts skill not found")
	}

	// Generate temp file
	outFile := filepath.Join(os.TempDir(), fmt.Sprintf("tts_%d.mp3", time.Now().UnixNano()))

	// Execute script
	// python3 script.py "text" --file outFile --no-play
	cmd := exec.Command("python3", scriptPath, cleanText, "--file", outFile, "--no-play")
	if out, err := cmd.CombinedOutput(); err != nil {
		return "", fmt.Errorf("tts execution failed: %v, output: %s", err, out)
	}

	return outFile, nil
}

func (al *AgentLoop) Run(ctx context.Context) error {
	al.running.Store(true)

	for al.running.Load() {
		select {
		case <-ctx.Done():
			return nil
		default:
			msg, ok := al.bus.ConsumeInbound(ctx)
			if !ok {
				continue
			}

			response, err := al.processMessage(ctx, msg)
			if err != nil {
				response = fmt.Sprintf("Error processing message: %v", err)
			}

			if response != "" {
				// Check if the message tool already sent a response during this round.
				// If so, skip publishing to avoid duplicate messages to the user.
				alreadySent := false
				if tool, ok := al.tools.Get("message"); ok {
					if mt, ok := tool.(*tools.MessageTool); ok {
						alreadySent = mt.HasSentInRound()
					}
				}

				if !alreadySent {
					var audioPath string
					// Try to generate audio
					if path, err := generateTTS(al.workspace, response); err == nil {
						audioPath = path
					} else {
						// Debug log if TTS fails (e.g. skill not found)
						logger.DebugCF("agent", "TTS generation skipped/failed", map[string]interface{}{
							"error": err.Error(),
						})
					}

					al.bus.PublishOutbound(bus.OutboundMessage{
						Channel:   msg.Channel,
						ChatID:    msg.ChatID,
						Content:   response,
						AudioPath: audioPath,
					})
				}
			}
		}
	}

	return nil
}

func (al *AgentLoop) Stop() {
	al.running.Store(false)
}

func (al *AgentLoop) RegisterTool(tool tools.Tool) {
	al.tools.Register(tool)
}

func (al *AgentLoop) SetChannelManager(cm *channels.Manager) {
	al.channelManager = cm
}

// 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(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(chatID)
}

func (al *AgentLoop) ProcessDirect(ctx context.Context, content, sessionKey string) (string, error) {
	return al.ProcessDirectWithChannel(ctx, content, sessionKey, "cli", "direct")
}

func (al *AgentLoop) ProcessDirectWithChannel(ctx context.Context, content, sessionKey, channel, chatID string) (string, error) {
	msg := bus.InboundMessage{
		Channel:    channel,
		SenderID:   "cron",
		ChatID:     chatID,
		Content:    content,
		SessionKey: sessionKey,
	}

	return al.processMessage(ctx, msg)
}

// ProcessHeartbeat processes a heartbeat request without session history.
// Each heartbeat is independent and doesn't accumulate context.
func (al *AgentLoop) ProcessHeartbeat(ctx context.Context, content, channel, chatID string) (string, error) {
	return al.runAgentLoop(ctx, processOptions{
		SessionKey:      "heartbeat",
		Channel:         channel,
		ChatID:          chatID,
		UserMessage:     content,
		DefaultResponse: "Saya telah selesai memproses pesan, namun tidak ada respons tambahan.",
		EnableSummary:   false,
		SendResponse:    false,
		NoHistory:       true, // Don't load session history for heartbeat
	})
}

func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage) (string, error) {
	// Add message preview to log (show full content for error messages)
	var logContent string
	if strings.Contains(msg.Content, "Error:") || strings.Contains(msg.Content, "error") {
		logContent = msg.Content // Full content for errors
	} else {
		logContent = utils.Truncate(msg.Content, 80)
	}
	logger.InfoCF("agent", fmt.Sprintf("Processing message from %s:%s: %s", msg.Channel, msg.SenderID, logContent),
		map[string]interface{}{
			"channel":     msg.Channel,
			"chat_id":     msg.ChatID,
			"sender_id":   msg.SenderID,
			"session_key": msg.SessionKey,
		})

	// Route system messages to processSystemMessage
	if msg.Channel == "system" {
		return al.processSystemMessage(ctx, msg)
	}

	// Check for commands
	if response, handled := al.handleCommand(ctx, msg); handled {
		return response, nil
	}

	// Process as user message
	return al.runAgentLoop(ctx, processOptions{
		SessionKey:      msg.SessionKey,
		Channel:         msg.Channel,
		ChatID:          msg.ChatID,
		UserMessage:     msg.Content,
		DefaultResponse: "Saya telah selesai memproses pesan, namun tidak ada respons tambahan.",
		EnableSummary:   true,
		SendResponse:    false,
		Media:           msg.Media,
	})
}

func (al *AgentLoop) processSystemMessage(ctx context.Context, msg bus.InboundMessage) (string, error) {
	// Verify this is a system message
	if msg.Channel != "system" {
		return "", fmt.Errorf("processSystemMessage called with non-system message channel: %s", msg.Channel)
	}

	logger.InfoCF("agent", "Processing system message",
		map[string]interface{}{
			"sender_id": msg.SenderID,
			"chat_id":   msg.ChatID,
		})

	// Parse origin channel from chat_id (format: "channel:chat_id")
	var originChannel string
	if idx := strings.Index(msg.ChatID, ":"); idx > 0 {
		originChannel = msg.ChatID[:idx]
	} else {
		// Fallback
		originChannel = "cli"
	}

	// Extract subagent result from message content
	// Format: "Task 'label' completed.\n\nResult:\n<actual content>"
	content := msg.Content
	if idx := strings.Index(content, "Result:\n"); idx >= 0 {
		content = content[idx+8:] // Extract just the result part
	}

	// Skip internal channels - only log, don't send to user
	if constants.IsInternalChannel(originChannel) {
		logger.InfoCF("agent", "Subagent completed (internal channel)",
			map[string]interface{}{
				"sender_id":   msg.SenderID,
				"content_len": len(content),
				"channel":     originChannel,
			})
		return "", nil
	}

	// Agent acts as dispatcher only - subagent handles user interaction via message tool
	// Don't forward result here, subagent should use message tool to communicate with user
	logger.InfoCF("agent", "Subagent completed",
		map[string]interface{}{
			"sender_id":   msg.SenderID,
			"channel":     originChannel,
			"content_len": len(content),
		})

	// Agent only logs, does not respond to user
	return "", nil
}

// runAgentLoop is the core message processing logic.
// It handles context building, LLM calls, tool execution, and response handling.
func (al *AgentLoop) runAgentLoop(ctx context.Context, opts processOptions) (string, error) {
	// 0. Record last channel for heartbeat notifications (skip internal channels)
	if opts.Channel != "" && opts.ChatID != "" {
		// Don't record internal channels (cli, system, subagent)
		if !constants.IsInternalChannel(opts.Channel) {
			channelKey := fmt.Sprintf("%s:%s", opts.Channel, opts.ChatID)
			if err := al.RecordLastChannel(channelKey); err != nil {
				logger.WarnCF("agent", "Failed to record last channel: %v", map[string]interface{}{"error": err.Error()})
			}
		}
	}

	// 1. Update tool contexts
	al.updateToolContexts(opts.Channel, opts.ChatID)

	// Determine adaptive iteration limit
	if opts.MaxIterations == 0 {
		// Heuristic:
		// - Short messages (< 50 chars): likely simple queries -> 10 iterations
		// - Medium messages (< 200 chars): standard tasks -> 25 iterations
		// - Long messages or complex keywords: complex tasks -> al.maxIterations (usually 50)
		msgLen := len(opts.UserMessage)
		opts.MaxIterations = 25 // Default medium

		if msgLen < 50 {
			opts.MaxIterations = 10
		} else if msgLen >= 200 {
			opts.MaxIterations = al.maxIterations
		}

		// Check for complexity keywords
		keywords := []string{"plan", "analyze", "research", "scan", "crawl", "recursive", "complex"}
		lowerMsg := strings.ToLower(opts.UserMessage)
		for _, kw := range keywords {
			if strings.Contains(lowerMsg, kw) {
				opts.MaxIterations = al.maxIterations + 10 // Boost for complex tasks
				break
			}
		}

		// Ensure we don't exceed a hard safety limit (e.g., 100) unless configured
		if opts.MaxIterations > 100 {
			opts.MaxIterations = 100
		}
	}
	
	logger.InfoCF("agent", "Adaptive iteration limit set", map[string]interface{}{
		"limit": opts.MaxIterations,
		"msg_len": len(opts.UserMessage),
	})

	// 2. Build messages (skip history for heartbeat)
	var history []providers.Message
	var summary string
	if !opts.NoHistory {
		history = al.sessions.GetHistory(opts.SessionKey)
		summary = al.sessions.GetSummary(opts.SessionKey)
	}
	messages := al.contextBuilder.BuildMessages(
		history,
		summary,
		opts.UserMessage,
		opts.Media,
		opts.Channel,
		opts.ChatID,
	)

	// 3. Save user message to session
	al.sessions.AddMessage(opts.SessionKey, "user", opts.UserMessage)

	// 4. Run LLM iteration loop
	finalContent, iteration, err := al.runLLMIteration(ctx, messages, opts)
	if err != nil {
		return "", err
	}

	// If last tool had ForUser content and we already sent it, we might not need to send final response
	// This is controlled by the tool's Silent flag and ForUser content

	// 5. Handle empty response
	if finalContent == "" {
		// Try to construct a meaningful response from the last action
		history := al.sessions.GetHistory(opts.SessionKey)
		if len(history) > 0 {
			lastMsg := history[len(history)-1]
			if lastMsg.Role == "tool" {
				// Find tool name from previous assistant message
				var toolName string
				if len(history) > 1 {
					prevMsg := history[len(history)-2]
					if prevMsg.Role == "assistant" {
						for _, tc := range prevMsg.ToolCalls {
							if tc.ID == lastMsg.ToolCallID {
								toolName = tc.Name
								break
							}
						}
					}
				}

				contentPreview := utils.Truncate(lastMsg.Content, 200)
				if toolName != "" {
					finalContent = fmt.Sprintf("Saya telah selesai menjalankan **%s**.\n\nHasil:\n%s", toolName, contentPreview)
				} else {
					finalContent = fmt.Sprintf("Proses selesai.\n\nHasil:\n%s", contentPreview)
				}
			}
		}

		// Fallback to default if still empty
		if finalContent == "" {
			finalContent = opts.DefaultResponse
		}
	}

	// 6. Save final assistant message to session
	al.sessions.AddMessage(opts.SessionKey, "assistant", finalContent)
	al.sessions.Save(opts.SessionKey)

	// 7. Optional: summarization
	if opts.EnableSummary {
		al.maybeSummarize(opts.SessionKey, opts.Channel, opts.ChatID)
	}

	// 8. Optional: send response via bus
	if opts.SendResponse {
		al.bus.PublishOutbound(bus.OutboundMessage{
			Channel: opts.Channel,
			ChatID:  opts.ChatID,
			Content: finalContent,
		})
	}

	// 9. Log response
	responsePreview := utils.Truncate(finalContent, 120)
	logger.InfoCF("agent", fmt.Sprintf("Response: %s", responsePreview),
		map[string]interface{}{
			"session_key":  opts.SessionKey,
			"iterations":   iteration,
			"final_length": len(finalContent),
		})

	return finalContent, nil
}

// runLLMIteration executes the LLM call loop with tool handling.
// Returns the final content, iteration count, and any error.
func (al *AgentLoop) runLLMIteration(ctx context.Context, messages []providers.Message, opts processOptions) (string, int, error) {
	iteration := 0
	var finalContent string
	
	// Use config for dynamic values if not overridden
	maxIterations := opts.MaxIterations
	if maxIterations <= 0 {
		if al.config != nil {
			maxIterations = al.config.GetAgentDefaults().MaxToolIterations
		}
		if maxIterations <= 0 {
			maxIterations = al.maxIterations
		}
	}

	for iteration < maxIterations {
		iteration++
		metrics.AgentIterations.Inc()

		// Adaptive iteration limit:
		// If we are nearing the limit but the agent is still using tools effectively (not looping),
		// we might want to extend the limit slightly.
		// For now, let's implement a simple check: if we hit the limit, but the last action was a successful tool call
		// that produced new information (not an error), we could allow 1-2 more iterations.
		// However, to keep it simple and safe, we'll just log a warning if we hit the limit.
		if iteration == maxIterations {
			logger.WarnCF("agent", "Max iterations reached", map[string]interface{}{
				"limit": maxIterations,
			})
		}

		logger.DebugCF("agent", "LLM iteration",
			map[string]interface{}{
				"iteration": iteration,
				"max":       maxIterations,
			})

		// Build tool definitions
		providerToolDefs := al.tools.ToProviderDefs()

		// Log LLM request details
		logger.DebugCF("agent", "LLM request",
			map[string]interface{}{
				"iteration":         iteration,
				"model":             al.model,
				"messages_count":    len(messages),
				"tools_count":       len(providerToolDefs),
				"max_tokens":        8192,
				"temperature":       0.7,
				"system_prompt_len": len(messages[0].Content),
			})

		// Log full messages (detailed)
		logger.DebugCF("agent", "Full LLM request",
			map[string]interface{}{
				"iteration":     iteration,
				"messages_json": formatMessagesForLog(messages),
				"tools_json":    formatToolsForLog(providerToolDefs),
			})

		var response *providers.LLMResponse
		var err error

		// Create list of models to try: [current_model, fallback_1, fallback_2, ...]
		modelsToTry := []string{al.model}
		if len(al.fallbackModels) > 0 {
			modelsToTry = append(modelsToTry, al.fallbackModels...)
		} else {
			// Legacy/Fallback hardcoded if config is empty
			backupModels := []string{
				"arcee-ai/trinity-large-preview:free",
			}
			modelsToTry = append(modelsToTry, backupModels...)
		}

		modelSuccess := false

		for modelIdx, modelToUse := range modelsToTry {
			// Retry loop for context/token errors
			maxRetries := 2
			for retry := 0; retry <= maxRetries; retry++ {
				response, err = al.provider.Chat(ctx, messages, providerToolDefs, modelToUse, map[string]interface{}{
					"max_tokens":  8192,
					"temperature": 0.7,
				})

				if err == nil {
					modelSuccess = true
					metrics.LLMRequests.WithLabelValues(modelToUse, "success").Inc()
					break // Success
				}
				metrics.LLMRequests.WithLabelValues(modelToUse, "error").Inc()

				errMsg := strings.ToLower(err.Error())
				// Check for context window errors (provider specific, but usually contain "token" or "invalid")
				isContextError := strings.Contains(errMsg, "token") ||
					strings.Contains(errMsg, "context") ||
					strings.Contains(errMsg, "invalidparameter") ||
					strings.Contains(errMsg, "length")

				// Check for transient errors (network, server error)
				isTransientError := strings.Contains(errMsg, "timeout") ||
					strings.Contains(errMsg, "connection") ||
					strings.Contains(errMsg, "500") ||
					strings.Contains(errMsg, "502") ||
					strings.Contains(errMsg, "503") ||
					strings.Contains(errMsg, "504") ||
					strings.Contains(errMsg, "rate limit") ||
					strings.Contains(errMsg, "429")

				if (isContextError || isTransientError) && retry < maxRetries {
					logger.WarnCF("agent", "Recoverable error detected, retrying with backoff", map[string]interface{}{
						"error":        err.Error(),
						"retry":        retry,
						"model":        modelToUse,
						"is_context":   isContextError,
						"is_transient": isTransientError,
					})

					// Exponential backoff: 1s, 2s, 4s
					backoff := time.Duration(1<<retry) * time.Second
					time.Sleep(backoff)

					if isContextError {
						if retry == 0 && !constants.IsInternalChannel(opts.Channel) && opts.SendResponse {
							al.bus.PublishOutbound(bus.OutboundMessage{
								Channel: opts.Channel,
								ChatID:  opts.ChatID,
								Content: "⚠️ Context window exceeded. Compressing history and retrying...",
							})
						}
						// Apply compression logic if needed (currently simple retry)
						// Ideally call al.forceCompression(opts.SessionKey) here if we had access to modify history in-place
						// But history is passed as argument 'messages'. 
						// To fix context error, we MUST reduce 'messages'.
						
						// Simple truncation for retry
						if len(messages) > 2 {
							// Drop a few oldest messages from the middle (preserve system prompt and last few)
							// messages[0] is system.
							// Remove messages[1] and messages[2] if available
							if len(messages) > 4 {
								// Remove 2 messages (user+assistant pair usually)
								newMessages := make([]providers.Message, 0, len(messages)-2)
								newMessages = append(newMessages, messages[0])
								newMessages = append(newMessages, messages[3:]...)
								messages = newMessages
								logger.WarnCF("agent", "Dropped 2 oldest messages for retry", nil)
							}
						}
					}
				} else {
					// Non-recoverable or max retries reached
					break
				}
			}

			if modelSuccess {
				if modelToUse != al.model {
					logger.WarnCF("agent", "Switched to fallback model", map[string]interface{}{
						"original": al.model,
						"current":  modelToUse,
					})
				}
				break
			}
			
			logger.WarnCF("agent", "Model failed, checking fallbacks", map[string]interface{}{
				"model":       modelToUse,
				"error":       err.Error(),
				"has_more":    modelIdx < len(modelsToTry)-1,
			})
		}

		if !modelSuccess {
			logger.ErrorCF("agent", "LLM call failed after all models tried", map[string]interface{}{
				"error": err.Error(),
			})
			return "", iteration, fmt.Errorf("LLM call failed after all models tried: %w", err)
		}


		// Check if no tool calls - we're done
		if len(response.ToolCalls) == 0 {
			finalContent = response.Content
			logger.InfoCF("agent", "LLM response without tool calls (direct answer)",
				map[string]interface{}{
					"iteration":     iteration,
					"content_chars": len(finalContent),
				})
			break
		}

		// Log tool calls
		toolNames := make([]string, 0, len(response.ToolCalls))
		for _, tc := range response.ToolCalls {
			toolNames = append(toolNames, tc.Name)
		}
		logger.InfoCF("agent", "LLM requested tool calls",
			map[string]interface{}{
				"tools":     toolNames,
				"count":     len(response.ToolCalls),
				"iteration": iteration,
			})

		// Build assistant message with tool calls
		assistantMsg := providers.Message{
			Role:    "assistant",
			Content: response.Content,
		}
		for _, tc := range response.ToolCalls {
			argumentsJSON, _ := json.Marshal(tc.Arguments)
			assistantMsg.ToolCalls = append(assistantMsg.ToolCalls, providers.ToolCall{
				ID:   tc.ID,
				Type: "function",
				Function: &providers.FunctionCall{
					Name:      tc.Name,
					Arguments: string(argumentsJSON),
				},
			})
		}
		messages = append(messages, assistantMsg)

		// Save assistant message with tool calls to session
		al.sessions.AddFullMessage(opts.SessionKey, assistantMsg)

		// Execute tool calls
		// We execute read-only tools in parallel, and side-effect tools sequentially to preserve causality.
		// Results must be appended to messages in the original order.
		results := make([]providers.Message, len(response.ToolCalls))
		executed := make([]bool, len(response.ToolCalls))

		// Helper to check if tool is safe for parallel execution
		isSafe := func(name string) bool {
			switch name {
			case "read_file", "list_dir", "web_fetch", "web_search", "weather":
				return true
			default:
				return false
			}
		}

		// Helper to check if tool result is cacheable
		isCacheable := func(name string) bool {
			switch name {
			case "read_file", "list_dir":
				return true
			default:
				return false
			}
		}

		i := 0
		for i < len(response.ToolCalls) {
			// Identify a batch of safe tools
			start := i
			end := i
			
			if isSafe(response.ToolCalls[i].Name) {
				// Extend batch while tools are safe
				for end < len(response.ToolCalls) && isSafe(response.ToolCalls[end].Name) {
					end++
				}
			} else {
				// Single unsafe tool
				end = i + 1
			}

			// Execute batch
			var wg sync.WaitGroup
			for j := start; j < end; j++ {
				wg.Add(1)
				go func(idx int, tc providers.ToolCall) {
					defer wg.Done()

					// Log tool call with arguments preview
					argsJSON, _ := json.Marshal(tc.Arguments)
					argsPreview := utils.Truncate(string(argsJSON), 200)
					logger.InfoCF("agent", fmt.Sprintf("Tool call: %s(%s)", tc.Name, argsPreview),
						map[string]interface{}{
							"tool":      tc.Name,
							"iteration": iteration,
						})

					var toolResult *tools.ToolResult
					var cacheKey string

					// Check cache for deterministic tools
					if isCacheable(tc.Name) {
						cacheKey = tc.Name + ":" + string(argsJSON)
						al.cacheMutex.RLock()
						if entry, ok := al.cache[cacheKey]; ok && time.Now().Before(entry.ExpiresAt) {
							toolResult = entry.Result
							logger.DebugCF("agent", "Cache hit for tool", map[string]interface{}{"tool": tc.Name})
							metrics.ToolCacheHits.WithLabelValues(tc.Name).Inc()
						} else {
							metrics.ToolCacheMisses.WithLabelValues(tc.Name).Inc()
						}
						al.cacheMutex.RUnlock()
					}

					if toolResult == nil {
						// Create async callback
						asyncCallback := func(callbackCtx context.Context, result *tools.ToolResult) {
							if !result.Silent && result.ForUser != "" {
								logger.InfoCF("agent", "Async tool completed, agent will handle notification",
									map[string]interface{}{
										"tool":        tc.Name,
										"content_len": len(result.ForUser),
									})
							}
						}

						// Retry logic for tool execution
						maxRetries := 2
						for retry := 0; retry <= maxRetries; retry++ {
							toolResult = al.tools.ExecuteWithContext(ctx, tc.Name, tc.Arguments, opts.Channel, opts.ChatID, asyncCallback)
							
							if toolResult.Err == nil {
								break
							}
							
							// Check for transient errors
							errMsg := strings.ToLower(toolResult.Err.Error())
							isTransient := strings.Contains(errMsg, "timeout") ||
								strings.Contains(errMsg, "connection") ||
								strings.Contains(errMsg, "rate limit") ||
								strings.Contains(errMsg, "429") ||
								strings.Contains(errMsg, "500") ||
								strings.Contains(errMsg, "502") ||
								strings.Contains(errMsg, "503") ||
								strings.Contains(errMsg, "504") ||
								strings.Contains(errMsg, "temporary")

							if !isTransient {
								break
							}
							
							if retry < maxRetries {
								logger.WarnCF("agent", "Tool execution failed, retrying", map[string]interface{}{
									"tool":  tc.Name,
									"error": toolResult.Err.Error(),
									"retry": retry,
								})
								time.Sleep(time.Duration(1<<retry) * time.Second)
							}
						}

						// Update cache if successful
						if isCacheable(tc.Name) && toolResult.Err == nil {
							al.cacheMutex.Lock()
							al.cache[cacheKey] = ToolCacheEntry{
								Result:    toolResult,
								ExpiresAt: time.Now().Add(60 * time.Second), // 60s TTL
							}
							al.cacheMutex.Unlock()
						}
					}

					// Send ForUser content to user immediately if not Silent
					if !toolResult.Silent && toolResult.ForUser != "" && opts.SendResponse {
						al.bus.PublishOutbound(bus.OutboundMessage{
							Channel: opts.Channel,
							ChatID:  opts.ChatID,
							Content: toolResult.ForUser,
						})
						logger.DebugCF("agent", "Sent tool result to user",
							map[string]interface{}{
								"tool":        tc.Name,
								"content_len": len(toolResult.ForUser),
							})
					}

					// Determine content for LLM based on tool result
					contentForLLM := toolResult.ForLLM
					if contentForLLM == "" && toolResult.Err != nil {
						contentForLLM = toolResult.Err.Error()
					}

					results[idx] = providers.Message{
						Role:       "tool",
						Content:    contentForLLM,
						ToolCallID: tc.ID,
					}
					executed[idx] = true
				}(j, response.ToolCalls[j])
			}
			wg.Wait()
			i = end
		}

		// Append results to messages and session in order
		for idx, res := range results {
			if !executed[idx] {
				// Should not happen if logic is correct
				logger.ErrorCF("agent", "Tool result missing for index", map[string]interface{}{"index": idx})
				continue
			}
			messages = append(messages, res)
			al.sessions.AddFullMessage(opts.SessionKey, res)
		}

		// Automatic iteration extension
		// If we reached the limit but just finished executing tools, the task is likely not done.
		// We extend the limit to allow the agent to finish, up to a hard safety limit.
		if iteration >= maxIterations {
			hardLimit := 100 // Default safety hard limit
			// If config has a higher limit, respect that + buffer
			if al.config != nil {
				configLimit := al.config.GetAgentDefaults().MaxToolIterations
				if configLimit > hardLimit {
					hardLimit = configLimit + 20
				}
			}

			if maxIterations < hardLimit {
				extension := 10
				newLimit := maxIterations + extension
				if newLimit > hardLimit {
					newLimit = hardLimit
				}

				if newLimit > maxIterations {
					logger.WarnCF("agent", "Auto-extending iteration limit", map[string]interface{}{
						"old_limit": maxIterations,
						"new_limit": newLimit,
						"reason":    "task ongoing",
					})
					maxIterations = newLimit
					
					// Notify user slightly if it's a significant extension
					if maxIterations > 30 && !constants.IsInternalChannel(opts.Channel) && opts.SendResponse {
						// Only send a subtle notification once or if really long
						if maxIterations == 40 || maxIterations == 70 {
							al.bus.PublishOutbound(bus.OutboundMessage{
								Channel: opts.Channel,
								ChatID:  opts.ChatID,
								Content: fmt.Sprintf("🔄 Memperpanjang waktu proses (%d langkah)...", maxIterations),
							})
						}
					}
				}
			}
		}
	}

	return finalContent, iteration, nil
}



// updateToolContexts updates the context for tools that need channel/chatID info.
func (al *AgentLoop) updateToolContexts(channel, chatID string) {
	// Use ContextualTool interface instead of type assertions
	if tool, ok := al.tools.Get("message"); ok {
		if mt, ok := tool.(tools.ContextualTool); ok {
			mt.SetContext(channel, chatID)
		}
	}
	if tool, ok := al.tools.Get("spawn"); ok {
		if st, ok := tool.(tools.ContextualTool); ok {
			st.SetContext(channel, chatID)
		}
	}
	if tool, ok := al.tools.Get("subagent"); ok {
		if st, ok := tool.(tools.ContextualTool); ok {
			st.SetContext(channel, chatID)
		}
	}
}

// maybeSummarize triggers summarization if the session history exceeds thresholds.
func (al *AgentLoop) maybeSummarize(sessionKey, channel, chatID string) {
	newHistory := al.sessions.GetHistory(sessionKey)
	tokenEstimate := al.estimateTokens(newHistory)
	threshold := al.contextWindow * 75 / 100

	if len(newHistory) > 20 || tokenEstimate > threshold {
		if _, loading := al.summarizing.LoadOrStore(sessionKey, true); !loading {
			go func() {
				defer al.summarizing.Delete(sessionKey)
				// Notify user about optimization if not an internal channel
				if !constants.IsInternalChannel(channel) {
					al.bus.PublishOutbound(bus.OutboundMessage{
						Channel: channel,
						ChatID:  chatID,
						Content: "🧹 Sedang merapikan ingatan percakapan untuk menjaga performa...",
					})
				}
				al.summarizeSession(sessionKey)
			}()
		}
	}
}

// forceCompression aggressively reduces context when the limit is hit.
// It drops the oldest 50% of messages (keeping system prompt and last user message).
func (al *AgentLoop) forceCompression(sessionKey string) {
	history := al.sessions.GetHistory(sessionKey)
	if len(history) <= 4 {
		return
	}

	// Keep system prompt (usually [0]) and the very last message (user's trigger)
	// We want to drop the oldest half of the *conversation*
	// Assuming [0] is system, [1:] is conversation
	conversation := history[1 : len(history)-1]
	if len(conversation) == 0 {
		return
	}

	// Helper to find the mid-point of the conversation
	mid := len(conversation) / 2

	// New history structure:
	// 1. System Prompt
	// 2. [Summary of dropped part] - synthesized
	// 3. Second half of conversation
	// 4. Last message

	// Simplified approach for emergency: Drop first half of conversation
	// and rely on existing summary if present, or create a placeholder.

	droppedCount := mid
	keptConversation := conversation[mid:]

	newHistory := make([]providers.Message, 0)
	newHistory = append(newHistory, history[0]) // System prompt

	// Add a note about compression
	compressionNote := fmt.Sprintf("[System: Emergency compression dropped %d oldest messages due to context limit]", droppedCount)
	// If there was an existing summary, we might lose it if it was in the dropped part (which is just messages).
	// The summary is stored separately in session.Summary, so it persists!
	// We just need to ensure the user knows there's a gap.

	// We only modify the messages list here
	newHistory = append(newHistory, providers.Message{
		Role:    "system",
		Content: compressionNote,
	})

	newHistory = append(newHistory, keptConversation...)
	newHistory = append(newHistory, history[len(history)-1]) // Last message

	// Update session
	al.sessions.SetHistory(sessionKey, newHistory)
	al.sessions.Save(sessionKey)

	logger.WarnCF("agent", "Forced compression executed", map[string]interface{}{
		"session_key":  sessionKey,
		"dropped_msgs": droppedCount,
		"new_count":    len(newHistory),
	})
}

// GetStartupInfo returns information about loaded tools and skills for logging.
func (al *AgentLoop) GetStartupInfo() map[string]interface{} {
	info := make(map[string]interface{})

	// Tools info
	tools := al.tools.List()
	info["tools"] = map[string]interface{}{
		"count": len(tools),
		"names": tools,
	}

	// Skills info
	info["skills"] = al.contextBuilder.GetSkillsInfo()

	return info
}

// formatMessagesForLog formats messages for logging
func formatMessagesForLog(messages []providers.Message) string {
	if len(messages) == 0 {
		return "[]"
	}

	buf := utils.GetBuffer()
	defer utils.PutBuffer(buf)

	buf.WriteString("[\n")
	for i, msg := range messages {
		buf.WriteString(fmt.Sprintf("  [%d] Role: %s\n", i, msg.Role))
		if len(msg.ToolCalls) > 0 {
			buf.WriteString("  ToolCalls:\n")
			for _, tc := range msg.ToolCalls {
				buf.WriteString(fmt.Sprintf("    - ID: %s, Type: %s, Name: %s\n", tc.ID, tc.Type, tc.Name))
				if tc.Function != nil {
					buf.WriteString(fmt.Sprintf("      Arguments: %s\n", utils.Truncate(tc.Function.Arguments, 200)))
				}
			}
		}
		if msg.Content != "" {
			content := utils.Truncate(msg.Content, 200)
			buf.WriteString(fmt.Sprintf("  Content: %s\n", content))
		}
		if msg.ToolCallID != "" {
			buf.WriteString(fmt.Sprintf("  ToolCallID: %s\n", msg.ToolCallID))
		}
		buf.WriteString("\n")
	}
	buf.WriteString("]")
	return buf.String()
}

// formatToolsForLog formats tool definitions for logging
func formatToolsForLog(tools []providers.ToolDefinition) string {
	if len(tools) == 0 {
		return "[]"
	}

	buf := utils.GetBuffer()
	defer utils.PutBuffer(buf)

	buf.WriteString("[\n")
	for i, tool := range tools {
		buf.WriteString(fmt.Sprintf("  [%d] Type: %s, Name: %s\n", i, tool.Type, tool.Function.Name))
		buf.WriteString(fmt.Sprintf("      Description: %s\n", tool.Function.Description))
		if len(tool.Function.Parameters) > 0 {
			buf.WriteString(fmt.Sprintf("      Parameters: %s\n", utils.Truncate(fmt.Sprintf("%v", tool.Function.Parameters), 200)))
		}
	}
	buf.WriteString("]")
	return buf.String()
}

// summarizeSession summarizes the conversation history for a session.
func (al *AgentLoop) summarizeSession(sessionKey string) {
	ctx, cancel := context.WithTimeout(context.Background(), 120*time.Second)
	defer cancel()

	history := al.sessions.GetHistory(sessionKey)
	summary := al.sessions.GetSummary(sessionKey)

	// Keep last 4 messages for continuity
	if len(history) <= 4 {
		return
	}

	toSummarize := history[:len(history)-4]

	// Oversized Message Guard
	// Skip messages larger than 50% of context window to prevent summarizer overflow
	maxMessageTokens := al.contextWindow / 2
	validMessages := make([]providers.Message, 0)
	omitted := false

	for _, m := range toSummarize {
		if m.Role != "user" && m.Role != "assistant" {
			continue
		}
		// Estimate tokens for this message
		msgTokens := len(m.Content) / 2 // Use safer estimate here too (2.5 -> 2 for integer division safety)
		if msgTokens > maxMessageTokens {
			omitted = true
			continue
		}
		validMessages = append(validMessages, m)
	}

	if len(validMessages) == 0 {
		return
	}

	// Multi-Part Summarization
	// Split into two parts if history is significant
	var finalSummary string
	if len(validMessages) > 10 {
		mid := len(validMessages) / 2
		part1 := validMessages[:mid]
		part2 := validMessages[mid:]

		s1, _ := al.summarizeBatch(ctx, part1, "")
		s2, _ := al.summarizeBatch(ctx, part2, "")

		// Merge them
		mergePrompt := fmt.Sprintf("Merge these two conversation summaries into one cohesive summary:\n\n1: %s\n\n2: %s", s1, s2)
		resp, err := al.provider.Chat(ctx, []providers.Message{{Role: "user", Content: mergePrompt}}, nil, al.model, map[string]interface{}{
			"max_tokens":  1024,
			"temperature": 0.3,
		})
		if err == nil {
			finalSummary = resp.Content
		} else {
			finalSummary = s1 + " " + s2
		}
	} else {
		finalSummary, _ = al.summarizeBatch(ctx, validMessages, summary)
	}

	if omitted && finalSummary != "" {
		finalSummary += "\n[Note: Some oversized messages were omitted from this summary for efficiency.]"
	}

	if finalSummary != "" {
		al.sessions.SetSummary(sessionKey, finalSummary)
		al.sessions.TruncateHistory(sessionKey, 4)
		al.sessions.Save(sessionKey)
	}
}

// summarizeBatch summarizes a batch of messages.
func (al *AgentLoop) summarizeBatch(ctx context.Context, batch []providers.Message, existingSummary string) (string, error) {
	prompt := "Provide a concise summary of this conversation segment, preserving core context and key points.\n"
	if existingSummary != "" {
		prompt += "Existing context: " + existingSummary + "\n"
	}
	prompt += "\nCONVERSATION:\n"
	for _, m := range batch {
		prompt += fmt.Sprintf("%s: %s\n", m.Role, m.Content)
	}

	response, err := al.provider.Chat(ctx, []providers.Message{{Role: "user", Content: prompt}}, nil, al.model, map[string]interface{}{
		"max_tokens":  1024,
		"temperature": 0.3,
	})
	if err != nil {
		return "", err
	}
	return response.Content, nil
}

// estimateTokens estimates the number of tokens in a message list.
// Uses a safe heuristic of 2.5 characters per token to account for CJK and other
// overheads better than the previous 3 chars/token.
func (al *AgentLoop) estimateTokens(messages []providers.Message) int {
	totalChars := 0
	for _, m := range messages {
		totalChars += utf8.RuneCountInString(m.Content)
	}
	// 2.5 chars per token = totalChars * 2 / 5
	return totalChars * 2 / 5
}

func (al *AgentLoop) handleCommand(ctx context.Context, msg bus.InboundMessage) (string, bool) {
	content := strings.TrimSpace(msg.Content)
	if !strings.HasPrefix(content, "/") {
		return "", false
	}

	parts := strings.Fields(content)
	if len(parts) == 0 {
		return "", false
	}

	cmd := parts[0]
	args := parts[1:]

	switch cmd {
	case "/show":
		if len(args) < 1 {
			return "Usage: /show [model|channel]", true
		}
		switch args[0] {
		case "model":
			return fmt.Sprintf("Current model: %s", al.model), true
		case "channel":
			return fmt.Sprintf("Current channel: %s", msg.Channel), true
		default:
			return fmt.Sprintf("Unknown show target: %s", args[0]), true
		}

	case "/list":
		if len(args) < 1 {
			return "Usage: /list [models|channels]", true
		}
		switch args[0] {
		case "models":
			// TODO: Fetch available models dynamically if possible
			return "Available models: glm-4.7, claude-3-5-sonnet, gpt-4o (configured in config.json/env)", true
		case "channels":
			if al.channelManager == nil {
				return "Channel manager not initialized", true
			}
			channels := al.channelManager.GetEnabledChannels()
			if len(channels) == 0 {
				return "No channels enabled", true
			}
			return fmt.Sprintf("Enabled channels: %s", strings.Join(channels, ", ")), true
		default:
			return fmt.Sprintf("Unknown list target: %s", args[0]), true
		}

	case "/switch":
		if len(args) < 3 || args[1] != "to" {
			return "Usage: /switch [model|channel] to <name>", true
		}
		target := args[0]
		value := args[2]

		switch target {
		case "model":
			oldModel := al.model
			al.model = value
			return fmt.Sprintf("Switched model from %s to %s", oldModel, value), true
		case "channel":
			// This changes the 'default' channel for some operations, or effectively redirects output?
			// For now, let's just validate if the channel exists
			if al.channelManager == nil {
				return "Channel manager not initialized", true
			}
			if _, exists := al.channelManager.GetChannel(value); !exists && value != "cli" {
				return fmt.Sprintf("Channel '%s' not found or not enabled", value), true
			}

			// If message came from CLI, maybe we want to redirect CLI output to this channel?
			// That would require state persistence about "redirected channel"
			// For now, just acknowledged.
			return fmt.Sprintf("Switched target channel to %s (Note: this currently only validates existence)", value), true
		default:
			return fmt.Sprintf("Unknown switch target: %s", target), true
		}
	}

	return "", false
}