package main

import (
	"flag"
	"fmt"
	"log"
	"math/rand"
	"os"
	"time"

	"github.com/aggregator-project/aggregator-agent/internal/cache"
	"github.com/aggregator-project/aggregator-agent/internal/client"
	"github.com/aggregator-project/aggregator-agent/internal/config"
	"github.com/aggregator-project/aggregator-agent/internal/display"
	"github.com/aggregator-project/aggregator-agent/internal/scanner"
	"github.com/google/uuid"
)

const (
	AgentVersion = "0.1.0"
	ConfigPath   = "/etc/aggregator/config.json"
)

func main() {
	registerCmd := flag.Bool("register", false, "Register agent with server")
	scanCmd := flag.Bool("scan", false, "Scan for updates and display locally")
	statusCmd := flag.Bool("status", false, "Show agent status")
	listUpdatesCmd := flag.Bool("list-updates", false, "List detailed update information")
	serverURL := flag.String("server", "http://localhost:8080", "Server URL")
	exportFormat := flag.String("export", "", "Export format: json, csv")
	flag.Parse()

	// Load configuration
	cfg, err := config.Load(ConfigPath)
	if err != nil {
		log.Fatal("Failed to load configuration:", err)
	}

	// Handle registration
	if *registerCmd {
		if err := registerAgent(cfg, *serverURL); err != nil {
			log.Fatal("Registration failed:", err)
		}
		fmt.Println("✓ Agent registered successfully!")
		fmt.Printf("Agent ID: %s\n", cfg.AgentID)
		return
	}

	// Handle scan command
	if *scanCmd {
		if err := handleScanCommand(cfg, *exportFormat); err != nil {
			log.Fatal("Scan failed:", err)
		}
		return
	}

	// Handle status command
	if *statusCmd {
		if err := handleStatusCommand(cfg); err != nil {
			log.Fatal("Status command failed:", err)
		}
		return
	}

	// Handle list-updates command
	if *listUpdatesCmd {
		if err := handleListUpdatesCommand(cfg, *exportFormat); err != nil {
			log.Fatal("List updates failed:", err)
		}
		return
	}

	// Check if registered
	if !cfg.IsRegistered() {
		log.Fatal("Agent not registered. Run with -register flag first.")
	}

	// Start agent service
	if err := runAgent(cfg); err != nil {
		log.Fatal("Agent failed:", err)
	}
}

func registerAgent(cfg *config.Config, serverURL string) error {
	hostname, _ := os.Hostname()
	osType, osVersion, osArch := client.DetectSystem()

	apiClient := client.NewClient(serverURL, "")

	req := client.RegisterRequest{
		Hostname:       hostname,
		OSType:         osType,
		OSVersion:      osVersion,
		OSArchitecture: osArch,
		AgentVersion:   AgentVersion,
		Metadata: map[string]string{
			"installation_time": time.Now().Format(time.RFC3339),
		},
	}

	resp, err := apiClient.Register(req)
	if err != nil {
		return err
	}

	// Update configuration
	cfg.ServerURL = serverURL
	cfg.AgentID = resp.AgentID
	cfg.Token = resp.Token

	// Get check-in interval from server config
	if interval, ok := resp.Config["check_in_interval"].(float64); ok {
		cfg.CheckInInterval = int(interval)
	} else {
		cfg.CheckInInterval = 300 // Default 5 minutes
	}

	// Save configuration
	return cfg.Save(ConfigPath)
}

func runAgent(cfg *config.Config) error {
	log.Printf("🚩 RedFlag Agent v%s starting...\n", AgentVersion)
	log.Printf("Agent ID: %s\n", cfg.AgentID)
	log.Printf("Server: %s\n", cfg.ServerURL)
	log.Printf("Check-in interval: %ds\n", cfg.CheckInInterval)

	apiClient := client.NewClient(cfg.ServerURL, cfg.Token)

	// Initialize scanners
	aptScanner := scanner.NewAPTScanner()
	dockerScanner, _ := scanner.NewDockerScanner()

	// Main check-in loop
	for {
		// Add jitter to prevent thundering herd
		jitter := time.Duration(rand.Intn(30)) * time.Second
		time.Sleep(jitter)

		log.Println("Checking in with server...")

		// Get commands from server
		commands, err := apiClient.GetCommands(cfg.AgentID)
		if err != nil {
			log.Printf("Error getting commands: %v\n", err)
			time.Sleep(time.Duration(cfg.CheckInInterval) * time.Second)
			continue
		}

		// Process each command
		for _, cmd := range commands {
			log.Printf("Processing command: %s (%s)\n", cmd.Type, cmd.ID)

			switch cmd.Type {
			case "scan_updates":
				if err := handleScanUpdates(apiClient, cfg, aptScanner, dockerScanner, cmd.ID); err != nil {
					log.Printf("Error scanning updates: %v\n", err)
				}

			case "collect_specs":
				log.Println("Spec collection not yet implemented")

			case "install_updates":
				log.Println("Update installation not yet implemented")

			default:
				log.Printf("Unknown command type: %s\n", cmd.Type)
			}
		}

		// Wait for next check-in
		time.Sleep(time.Duration(cfg.CheckInInterval) * time.Second)
	}
}

func handleScanUpdates(apiClient *client.Client, cfg *config.Config, aptScanner *scanner.APTScanner, dockerScanner *scanner.DockerScanner, commandID string) error {
	log.Println("Scanning for updates...")

	var allUpdates []client.UpdateReportItem

	// Scan APT updates
	if aptScanner.IsAvailable() {
		log.Println("  - Scanning APT packages...")
		updates, err := aptScanner.Scan()
		if err != nil {
			log.Printf("    APT scan failed: %v\n", err)
		} else {
			log.Printf("    Found %d APT updates\n", len(updates))
			allUpdates = append(allUpdates, updates...)
		}
	}

	// Scan Docker updates
	if dockerScanner != nil && dockerScanner.IsAvailable() {
		log.Println("  - Scanning Docker images...")
		updates, err := dockerScanner.Scan()
		if err != nil {
			log.Printf("    Docker scan failed: %v\n", err)
		} else {
			log.Printf("    Found %d Docker image updates\n", len(updates))
			allUpdates = append(allUpdates, updates...)
		}
	}

	// Report to server
	if len(allUpdates) > 0 {
		report := client.UpdateReport{
			CommandID: commandID,
			Timestamp: time.Now(),
			Updates:   allUpdates,
		}

		if err := apiClient.ReportUpdates(cfg.AgentID, report); err != nil {
			return fmt.Errorf("failed to report updates: %w", err)
		}

		log.Printf("✓ Reported %d updates to server\n", len(allUpdates))
	} else {
		log.Println("✓ No updates found")
	}

	return nil
}

// handleScanCommand performs a local scan and displays results
func handleScanCommand(cfg *config.Config, exportFormat string) error {
	// Initialize scanners
	aptScanner := scanner.NewAPTScanner()
	dockerScanner, _ := scanner.NewDockerScanner()

	fmt.Println("🔍 Scanning for updates...")
	var allUpdates []client.UpdateReportItem

	// Scan APT updates
	if aptScanner.IsAvailable() {
		fmt.Println("  - Scanning APT packages...")
		updates, err := aptScanner.Scan()
		if err != nil {
			fmt.Printf("    ⚠️  APT scan failed: %v\n", err)
		} else {
			fmt.Printf("    ✓ Found %d APT updates\n", len(updates))
			allUpdates = append(allUpdates, updates...)
		}
	}

	// Scan Docker updates
	if dockerScanner != nil && dockerScanner.IsAvailable() {
		fmt.Println("  - Scanning Docker images...")
		updates, err := dockerScanner.Scan()
		if err != nil {
			fmt.Printf("    ⚠️  Docker scan failed: %v\n", err)
		} else {
			fmt.Printf("    ✓ Found %d Docker image updates\n", len(updates))
			allUpdates = append(allUpdates, updates...)
		}
	}

	// Load and update cache
	localCache, err := cache.Load()
	if err != nil {
		fmt.Printf("⚠️  Warning: Failed to load cache: %v\n", err)
		localCache = &cache.LocalCache{}
	}

	// Update cache with scan results
	localCache.UpdateScanResults(allUpdates)
	if cfg.IsRegistered() {
		localCache.SetAgentInfo(cfg.AgentID, cfg.ServerURL)
		localCache.SetAgentStatus("online")
	}

	// Save cache
	if err := localCache.Save(); err != nil {
		fmt.Printf("⚠️  Warning: Failed to save cache: %v\n", err)
	}

	// Display results
	fmt.Println()
	return display.PrintScanResults(allUpdates, exportFormat)
}

// handleStatusCommand displays agent status information
func handleStatusCommand(cfg *config.Config) error {
	// Load cache
	localCache, err := cache.Load()
	if err != nil {
		return fmt.Errorf("failed to load cache: %w", err)
	}

	// Determine status
	agentStatus := "offline"
	if cfg.IsRegistered() {
		agentStatus = "online"
	}
	if localCache.AgentStatus != "" {
		agentStatus = localCache.AgentStatus
	}

	// Use cached info if available, otherwise use config
	agentID := cfg.AgentID.String()
	if localCache.AgentID != (uuid.UUID{}) {
		agentID = localCache.AgentID.String()
	}

	serverURL := cfg.ServerURL
	if localCache.ServerURL != "" {
		serverURL = localCache.ServerURL
	}

	// Display status
	display.PrintAgentStatus(
		agentID,
		serverURL,
		localCache.LastCheckIn,
		localCache.LastScanTime,
		localCache.UpdateCount,
		agentStatus,
	)

	return nil
}

// handleListUpdatesCommand displays detailed update information
func handleListUpdatesCommand(cfg *config.Config, exportFormat string) error {
	// Load cache
	localCache, err := cache.Load()
	if err != nil {
		return fmt.Errorf("failed to load cache: %w", err)
	}

	// Check if we have cached scan results
	if len(localCache.Updates) == 0 {
		fmt.Println("📋 No cached scan results found.")
		fmt.Println("💡 Run '--scan' first to discover available updates.")
		return nil
	}

	// Warn if cache is old
	if localCache.IsExpired(24 * time.Hour) {
		fmt.Printf("⚠️  Scan results are %s old. Run '--scan' for latest results.\n\n",
			formatTimeSince(localCache.LastScanTime))
	}

	// Display detailed results
	return display.PrintDetailedUpdates(localCache.Updates, exportFormat)
}

// formatTimeSince formats a duration as "X time ago"
func formatTimeSince(t time.Time) string {
	duration := time.Since(t)
	if duration < time.Minute {
		return fmt.Sprintf("%d seconds ago", int(duration.Seconds()))
	} else if duration < time.Hour {
		return fmt.Sprintf("%d minutes ago", int(duration.Minutes()))
	} else if duration < 24*time.Hour {
		return fmt.Sprintf("%d hours ago", int(duration.Hours()))
	} else {
		return fmt.Sprintf("%d days ago", int(duration.Hours()/24))
	}
}