package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"
	"strings"
	"sync"
	"time"

	"github.com/sashabaranov/go-openai"
)

// DiagnosticResponse represents the diagnostic phase response from AI
type DiagnosticResponse struct {
	ResponseType    string   `json:"response_type"`
	Phase           string   `json:"phase"`
	Analysis        string   `json:"analysis"`
	Commands        []string `json:"commands"`
	NextSteps       []string `json:"next_steps"`
	Reasoning       string   `json:"reasoning"`
	ConfidenceLevel float64  `json:"confidence_level"`
}

// EBPFRequest represents a request for eBPF program execution
type EBPFRequest struct {
	Name        string            `json:"name"`
	Type        string            `json:"type"`
	Target      string            `json:"target"`
	Duration    int               `json:"duration"`
	Filters     map[string]string `json:"filters,omitempty"`
	Description string            `json:"description"`
}

// EBPFEnhancedDiagnosticResponse represents the enhanced diagnostic response with eBPF
type EBPFEnhancedDiagnosticResponse struct {
	ResponseType    string        `json:"response_type"`
	Phase           string        `json:"phase"`
	Analysis        string        `json:"analysis"`
	Commands        []string      `json:"commands"`
	EBPFPrograms    []EBPFRequest `json:"ebpf_programs"`
	NextSteps       []string      `json:"next_steps"`
	Reasoning       string        `json:"reasoning"`
	ConfidenceLevel float64       `json:"confidence_level"`
}

// ResolutionResponse represents the resolution phase response from AI
type ResolutionResponse struct {
	ResponseType   string `json:"response_type"`
	RootCause      string `json:"root_cause"`
	ResolutionPlan string `json:"resolution_plan"`
	Confidence     string `json:"confidence"`
}

// Command represents a command to be executed
type Command struct {
	ID          string `json:"id"`
	Command     string `json:"command"`
	Description string `json:"description"`
}

// AgentConfig holds configuration for concurrent execution
type AgentConfig struct {
	MaxConcurrentTasks int  `json:"max_concurrent_tasks"`
	CollectiveResults  bool `json:"collective_results"`
}

// DefaultAgentConfig returns default configuration
func DefaultAgentConfig() *AgentConfig {
	return &AgentConfig{
		MaxConcurrentTasks: 10,   // Default to 10 concurrent forks
		CollectiveResults:  true, // Send results collectively when all finish
	}
}

// CommandResult represents the result of executing a command
type CommandResult struct {
	ID       string `json:"id"`
	Command  string `json:"command"`
	Output   string `json:"output"`
	ExitCode int    `json:"exit_code"`
	Error    string `json:"error,omitempty"`
}

// LinuxDiagnosticAgent represents the main agent
type LinuxDiagnosticAgent struct {
	client      *openai.Client
	model       string
	executor    *CommandExecutor
	episodeID   string           // TensorZero episode ID for conversation continuity
	ebpfManager *BCCTraceManager // BCC-style eBPF tracing capabilities
	config      *AgentConfig     // Configuration for concurrent execution
}

// NewLinuxDiagnosticAgent creates a new diagnostic agent
func NewLinuxDiagnosticAgent() *LinuxDiagnosticAgent {
	// Get Supabase project URL for TensorZero proxy
	supabaseURL := os.Getenv("SUPABASE_PROJECT_URL")
	if supabaseURL == "" {
		fmt.Printf("Warning: SUPABASE_PROJECT_URL not set, TensorZero integration will not work\n")
		supabaseURL = "https://gpqzsricripnvbrpsyws.supabase.co" // fallback
	}

	model := os.Getenv("NANNYAPI_MODEL")
	if model == "" {
		model = "tensorzero::function_name::diagnose_and_heal"
		fmt.Printf("Warning: Using default model '%s'. Set NANNYAPI_MODEL environment variable for your specific function.\n", model)
	}

	// Note: We don't use the OpenAI client anymore, we use direct HTTP to Supabase proxy
	agent := &LinuxDiagnosticAgent{
		client:   nil, // Not used anymore
		model:    model,
		executor: NewCommandExecutor(10 * time.Second), // 10 second timeout for commands
		config:   DefaultAgentConfig(),                 // Default concurrent execution config
	}

	// Initialize BCC-style eBPF capabilities
	agent.ebpfManager = NewBCCTraceManager()

	return agent
}

// DiagnoseIssue starts the diagnostic process for a given issue
func (a *LinuxDiagnosticAgent) DiagnoseIssue(issue string) error {
	fmt.Printf("Diagnosing issue: %s\n", issue)
	fmt.Println("Gathering system information...")

	// Gather system information
	systemInfo := GatherSystemInfo()

	// Format the initial prompt with system information
	initialPrompt := FormatSystemInfoForPrompt(systemInfo) + "\n" + issue

	// Start conversation with initial issue including system info
	messages := []openai.ChatCompletionMessage{
		{
			Role:    openai.ChatMessageRoleUser,
			Content: initialPrompt,
		},
	}

	for {
		// Send request to TensorZero API via OpenAI SDK
		response, err := a.sendRequestWithEpisode(messages, a.episodeID)
		if err != nil {
			return fmt.Errorf("failed to send request: %w", err)
		}

		if len(response.Choices) == 0 {
			return fmt.Errorf("no choices in response")
		}

		content := response.Choices[0].Message.Content
		fmt.Printf("\nAI Response:\n%s\n", content)

		// Parse the response to determine next action
		var diagnosticResp EBPFEnhancedDiagnosticResponse
		var resolutionResp ResolutionResponse

		// Try to parse as diagnostic response first (with eBPF support)
		if err := json.Unmarshal([]byte(content), &diagnosticResp); err == nil && diagnosticResp.ResponseType == "diagnostic" {
			// Handle diagnostic phase
			fmt.Printf("\nReasoning: %s\n", diagnosticResp.Reasoning)

			// Execute commands and collect results
			commandResults := make([]CommandResult, 0, len(diagnosticResp.Commands))
			if len(diagnosticResp.Commands) > 0 {
				fmt.Printf("🔧 Executing diagnostic commands...\n")
				for i, cmdStr := range diagnosticResp.Commands {
					// Convert string to Command struct
					cmd := Command{
						ID:          fmt.Sprintf("cmd_%d", i),
						Command:     cmdStr,
						Description: fmt.Sprintf("Diagnostic command: %s", cmdStr),
					}
					result := a.executor.Execute(cmd)
					commandResults = append(commandResults, result)

					if result.ExitCode != 0 {
						fmt.Printf("❌ Command '%s' failed with exit code %d\n", cmd.ID, result.ExitCode)
					}
				}
			}

			// Execute eBPF programs if present - support both old and new formats
			var ebpfResults []map[string]interface{}
			if len(diagnosticResp.EBPFPrograms) > 0 {
				fmt.Printf("🔬 AI requested %d eBPF traces for enhanced diagnostics\n", len(diagnosticResp.EBPFPrograms))

				// Convert EBPFPrograms to TraceSpecs and execute concurrently
				traceSpecs := a.convertEBPFProgramsToTraceSpecs(diagnosticResp.EBPFPrograms)
				ebpfResults = a.executeBCCTracesConcurrently(traceSpecs)
			}

			// Prepare combined results as user message
			allResults := map[string]interface{}{
				"command_results":   commandResults,
				"executed_commands": len(commandResults),
			}

			// Include eBPF results if any were executed
			if len(ebpfResults) > 0 {
				allResults["ebpf_results"] = ebpfResults
				allResults["executed_ebpf_programs"] = len(ebpfResults)

				// Extract evidence summary for TensorZero
				evidenceSummary := make([]string, 0)
				for _, result := range ebpfResults {
					name := result["name"]
					eventCount := result["data_points"]
					description := result["description"]
					status := result["status"]

					summaryStr := fmt.Sprintf("%s: %v events (%s) - %s", name, eventCount, status, description)
					evidenceSummary = append(evidenceSummary, summaryStr)
				}
				allResults["ebpf_evidence_summary"] = evidenceSummary
			}

			resultsJSON, err := json.MarshalIndent(allResults, "", "  ")
			if err != nil {
				return fmt.Errorf("failed to marshal command results: %w", err)
			}

			// Add AI response and command results to conversation
			messages = append(messages, openai.ChatCompletionMessage{
				Role:    openai.ChatMessageRoleAssistant,
				Content: content,
			})
			messages = append(messages, openai.ChatCompletionMessage{
				Role:    openai.ChatMessageRoleUser,
				Content: string(resultsJSON),
			})

			continue
		}

		// Try to parse as resolution response
		if err := json.Unmarshal([]byte(content), &resolutionResp); err == nil && resolutionResp.ResponseType == "resolution" {
			// Handle resolution phase
			fmt.Printf("\n=== DIAGNOSIS COMPLETE ===\n")
			fmt.Printf("Root Cause: %s\n", resolutionResp.RootCause)
			fmt.Printf("Resolution Plan: %s\n", resolutionResp.ResolutionPlan)
			fmt.Printf("Confidence: %s\n", resolutionResp.Confidence)
			break
		}

		// If we can't parse the response, treat it as an error or unexpected format
		fmt.Printf("Unexpected response format or error from AI:\n%s\n", content)
		break
	}

	return nil
}

// sendRequest sends a request to TensorZero via Supabase proxy (without episode ID)
func (a *LinuxDiagnosticAgent) sendRequest(messages []openai.ChatCompletionMessage) (*openai.ChatCompletionResponse, error) {
	return a.sendRequestWithEpisode(messages, "")
}

// sendRequestWithEpisode sends a request to TensorZero via Supabase proxy with episode ID for conversation continuity
func (a *LinuxDiagnosticAgent) sendRequestWithEpisode(messages []openai.ChatCompletionMessage, episodeID string) (*openai.ChatCompletionResponse, error) {
	// Convert messages to the expected format
	messageMaps := make([]map[string]interface{}, len(messages))
	for i, msg := range messages {
		messageMaps[i] = map[string]interface{}{
			"role":    msg.Role,
			"content": msg.Content,
		}
	}

	// Create TensorZero request
	tzRequest := map[string]interface{}{
		"model":    a.model,
		"messages": messageMaps,
	}

	// Add episode ID if provided
	if episodeID != "" {
		tzRequest["tensorzero::episode_id"] = episodeID
	}

	// Marshal request
	requestBody, err := json.Marshal(tzRequest)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal request: %w", err)
	}

	// Get Supabase URL
	supabaseURL := os.Getenv("SUPABASE_PROJECT_URL")
	if supabaseURL == "" {
		return nil, fmt.Errorf("SUPABASE_PROJECT_URL not set")
	}

	// Create HTTP request to TensorZero proxy
	endpoint := fmt.Sprintf("%s/functions/v1/tensorzero-proxy", supabaseURL)
	req, err := http.NewRequest("POST", endpoint, bytes.NewBuffer(requestBody))
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	// Set headers
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Accept", "application/json")

	// Note: No authentication needed for TensorZero proxy based on the existing pattern

	// Send request
	client := &http.Client{Timeout: 30 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

	// Check status code
	if resp.StatusCode != 200 {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("TensorZero proxy error: %d, body: %s", resp.StatusCode, string(body))
	}

	// Parse response
	var tzResponse map[string]interface{}
	if err := json.NewDecoder(resp.Body).Decode(&tzResponse); err != nil {
		return nil, fmt.Errorf("failed to decode response: %w", err)
	}

	// Convert to OpenAI format for compatibility
	choices, ok := tzResponse["choices"].([]interface{})
	if !ok || len(choices) == 0 {
		return nil, fmt.Errorf("no choices in response")
	}

	// Extract the first choice
	firstChoice, ok := choices[0].(map[string]interface{})
	if !ok {
		return nil, fmt.Errorf("invalid choice format")
	}

	message, ok := firstChoice["message"].(map[string]interface{})
	if !ok {
		return nil, fmt.Errorf("invalid message format")
	}

	content, ok := message["content"].(string)
	if !ok {
		return nil, fmt.Errorf("invalid content format")
	}

	// Create OpenAI-compatible response
	response := &openai.ChatCompletionResponse{
		Choices: []openai.ChatCompletionChoice{
			{
				Message: openai.ChatCompletionMessage{
					Role:    openai.ChatMessageRoleAssistant,
					Content: content,
				},
			},
		},
	}

	// Update episode ID if provided in response
	if respEpisodeID, ok := tzResponse["episode_id"].(string); ok && respEpisodeID != "" {
		a.episodeID = respEpisodeID
	}

	return response, nil
}

// convertEBPFProgramsToTraceSpecs converts old EBPFProgram format to new TraceSpec format
func (a *LinuxDiagnosticAgent) convertEBPFProgramsToTraceSpecs(ebpfPrograms []EBPFRequest) []TraceSpec {
	var traceSpecs []TraceSpec

	for _, prog := range ebpfPrograms {
		spec := a.convertToTraceSpec(prog)
		traceSpecs = append(traceSpecs, spec)
	}

	return traceSpecs
}

// convertToTraceSpec converts an EBPFRequest to a TraceSpec for BCC-style tracing
func (a *LinuxDiagnosticAgent) convertToTraceSpec(prog EBPFRequest) TraceSpec {
	// Determine probe type based on target and type
	probeType := "p" // default to kprobe
	target := prog.Target

	if strings.HasPrefix(target, "tracepoint:") {
		probeType = "t"
		target = strings.TrimPrefix(target, "tracepoint:")
	} else if strings.HasPrefix(target, "kprobe:") {
		probeType = "p"
		target = strings.TrimPrefix(target, "kprobe:")
	} else if prog.Type == "tracepoint" {
		probeType = "t"
	} else if prog.Type == "syscall" {
		// Convert syscall names to kprobe targets
		if !strings.HasPrefix(target, "__x64_sys_") && !strings.Contains(target, ":") {
			if strings.HasPrefix(target, "sys_") {
				target = "__x64_" + target
			} else {
				target = "__x64_sys_" + target
			}
		}
		probeType = "p"
	}

	// Set default duration if not specified
	duration := prog.Duration
	if duration <= 0 {
		duration = 5 // default 5 seconds
	}

	return TraceSpec{
		ProbeType: probeType,
		Target:    target,
		Format:    prog.Description, // Use description as format
		Arguments: []string{},       // Start with no arguments for compatibility
		Duration:  duration,
	}
}

// executeBCCTracesConcurrently executes multiple BCC traces concurrently with configurable parallelism
func (a *LinuxDiagnosticAgent) executeBCCTracesConcurrently(traceSpecs []TraceSpec) []map[string]interface{} {
	if len(traceSpecs) == 0 {
		return []map[string]interface{}{}
	}

	fmt.Printf("🚀 Executing %d BCC traces with max %d concurrent tasks\n", len(traceSpecs), a.config.MaxConcurrentTasks)

	// Channel to limit concurrent goroutines
	semaphore := make(chan struct{}, a.config.MaxConcurrentTasks)
	resultsChan := make(chan map[string]interface{}, len(traceSpecs))
	var wg sync.WaitGroup

	// Start all traces concurrently
	for i, spec := range traceSpecs {
		wg.Add(1)
		go func(index int, traceSpec TraceSpec) {
			defer wg.Done()

			// Acquire semaphore
			semaphore <- struct{}{}
			defer func() { <-semaphore }()

			result := a.executeSingleBCCTrace(index, traceSpec)
			resultsChan <- result
		}(i, spec)
	}

	// Wait for all traces to complete
	go func() {
		wg.Wait()
		close(resultsChan)
	}()

	// Collect all results
	var allResults []map[string]interface{}
	for result := range resultsChan {
		allResults = append(allResults, result)
	}

	if a.config.CollectiveResults {
		fmt.Printf("✅ All %d BCC traces completed. Sending collective results to API layer.\n", len(allResults))
	}

	return allResults
}

// executeSingleBCCTrace executes a single BCC trace and returns the result
func (a *LinuxDiagnosticAgent) executeSingleBCCTrace(index int, spec TraceSpec) map[string]interface{} {
	result := map[string]interface{}{
		"index":      index,
		"target":     spec.Target,
		"probe_type": spec.ProbeType,
		"success":    false,
		"error":      "",
		"start_time": time.Now().Format(time.RFC3339),
	}

	fmt.Printf("🔍 [Task %d] Starting BCC trace: %s (type: %s)\n", index, spec.Target, spec.ProbeType)

	// Start the trace
	traceID, err := a.ebpfManager.StartTrace(spec)
	if err != nil {
		result["error"] = fmt.Sprintf("Failed to start trace: %v", err)
		fmt.Printf("❌ [Task %d] Failed to start trace %s: %v\n", index, spec.Target, err)
		return result
	}

	result["trace_id"] = traceID
	fmt.Printf("🚀 [Task %d] Trace %s started with ID: %s\n", index, spec.Target, traceID)

	// Wait for the trace duration
	time.Sleep(time.Duration(spec.Duration) * time.Second)

	// Get the trace result
	traceResult, err := a.ebpfManager.GetTraceResult(traceID)
	if err != nil {
		// Try to stop the trace if it's still running
		a.ebpfManager.StopTrace(traceID)
		result["error"] = fmt.Sprintf("Failed to get trace results: %v", err)
		fmt.Printf("❌ [Task %d] Failed to get results for trace %s: %v\n", index, spec.Target, err)
		return result
	}

	// Populate result with trace data
	result["success"] = true
	result["end_time"] = time.Now().Format(time.RFC3339)
	result["event_count"] = traceResult.EventCount
	result["events_per_second"] = traceResult.Statistics.EventsPerSecond
	result["duration"] = traceResult.EndTime.Sub(traceResult.StartTime).Seconds()
	result["summary"] = traceResult.Summary

	// Include sample events (limit to avoid large payloads)
	maxSampleEvents := 10
	if len(traceResult.Events) > 0 {
		sampleCount := len(traceResult.Events)
		if sampleCount > maxSampleEvents {
			sampleCount = maxSampleEvents
		}

		sampleEvents := make([]map[string]interface{}, sampleCount)
		for i := 0; i < sampleCount; i++ {
			event := traceResult.Events[i]
			sampleEvents[i] = map[string]interface{}{
				"pid":          event.PID,
				"tid":          event.TID,
				"process_name": event.ProcessName,
				"message":      event.Message,
				"timestamp":    event.Timestamp,
			}
		}
		result["sample_events"] = sampleEvents
	}

	// Include top processes
	if len(traceResult.Statistics.TopProcesses) > 0 {
		topProcesses := make([]map[string]interface{}, len(traceResult.Statistics.TopProcesses))
		for i, proc := range traceResult.Statistics.TopProcesses {
			topProcesses[i] = map[string]interface{}{
				"process_name": proc.ProcessName,
				"event_count":  proc.EventCount,
				"percentage":   proc.Percentage,
			}
		}
		result["top_processes"] = topProcesses
	}

	fmt.Printf("✅ [Task %d] Trace %s completed: %d events (%.2f events/sec)\n",
		index, spec.Target, traceResult.EventCount, traceResult.Statistics.EventsPerSecond)

	return result
}