package app

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log/slog"
	"net/http"
	"os"
	"os/signal"
	"strings"
	"syscall"
	"time"

	"git.nakama.town/fmartingr/butterrobot/internal/admin"
	"git.nakama.town/fmartingr/butterrobot/internal/config"
	"git.nakama.town/fmartingr/butterrobot/internal/db"
	"git.nakama.town/fmartingr/butterrobot/internal/platform"
	"git.nakama.town/fmartingr/butterrobot/internal/plugin"
	"git.nakama.town/fmartingr/butterrobot/internal/plugin/fun"
	"git.nakama.town/fmartingr/butterrobot/internal/plugin/ping"
	"git.nakama.town/fmartingr/butterrobot/internal/plugin/social"
	"git.nakama.town/fmartingr/butterrobot/internal/queue"
)

// App represents the application
type App struct {
	config *config.Config
	logger *slog.Logger
	db     *db.Database
	router *http.ServeMux
	queue  *queue.Queue
	admin  *admin.Admin
}

// New creates a new App instance
func New(cfg *config.Config, logger *slog.Logger) (*App, error) {
	// Initialize router
	router := http.NewServeMux()

	// Initialize database
	database, err := db.New(cfg.DatabasePath)
	if err != nil {
		return nil, fmt.Errorf("failed to initialize database: %w", err)
	}

	// Initialize message queue
	messageQueue := queue.New(logger)

	// Initialize admin interface
	adminInterface := admin.New(cfg, database)

	return &App{
		config: cfg,
		logger: logger,
		db:     database,
		router: router,
		queue:  messageQueue,
		admin:  adminInterface,
	}, nil
}

// Run starts the application
func (a *App) Run() error {
	// Initialize platforms
	if err := platform.InitializePlatforms(a.config); err != nil {
		return err
	}

	// Register built-in plugins
	plugin.Register(ping.New())
	plugin.Register(fun.NewCoin())
	plugin.Register(fun.NewDice())
	plugin.Register(fun.NewLoquito())
	plugin.Register(social.NewTwitterExpander())
	plugin.Register(social.NewInstagramExpander())

	// Initialize routes
	a.initializeRoutes()

	// Start message queue worker
	a.queue.Start(a.handleMessage)

	// Create server
	addr := fmt.Sprintf(":%s", a.config.Port)
	srv := &http.Server{
		Addr:    addr,
		Handler: a.router,
	}

	// Start server in a goroutine
	go func() {
		a.logger.Info("Server starting on", "addr", addr)
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			a.logger.Error("Server error", "error", err)
			os.Exit(1)
		}
	}()

	// Wait for interrupt signal
	quit := make(chan os.Signal, 1)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit

	a.logger.Info("Shutting down server...")

	// Create shutdown context with timeout
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	// Shutdown server
	if err := srv.Shutdown(ctx); err != nil {
		return err
	}

	// Stop message queue
	a.queue.Stop()

	// Close database connection
	if err := a.db.Close(); err != nil {
		return err
	}

	a.logger.Info("Server stopped")

	return nil
}

// Initialize HTTP routes
func (a *App) initializeRoutes() {
	// Health check endpoint
	a.router.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusOK)
		json.NewEncoder(w).Encode(map[string]interface{}{})
	})

	// Platform webhook endpoints
	for name := range platform.GetAvailablePlatforms() {
		a.logger.Info("Registering webhook endpoint for platform", "platform", name)
		platformName := name // Create a copy to avoid closure issues
		a.router.HandleFunc("/"+platformName+"/incoming/", a.handleIncomingWebhook)
	}

	// Register admin routes
	a.admin.RegisterRoutes(a.router)
}

// Handle incoming webhook
func (a *App) handleIncomingWebhook(w http.ResponseWriter, r *http.Request) {
	// Extract platform name from path
	platformName := extractPlatformName(r.URL.Path)

	// Check if platform exists
	if _, err := platform.Get(platformName); err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusBadRequest)
		json.NewEncoder(w).Encode(map[string]string{"error": "Unknown platform"})
		return
	}

	// Read request body
	body, err := io.ReadAll(r.Body)
	if err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusBadRequest)
		json.NewEncoder(w).Encode(map[string]string{"error": "Failed to read request body"})
		return
	}

	// Queue message for processing
	a.queue.Add(queue.Item{
		Platform: platformName,
		Request: map[string]any{
			"path": r.URL.Path,
			"json": json.RawMessage(body),
		},
	})

	// Respond with success
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(map[string]any{})
}

// extractPlatformName extracts the platform name from the URL path
func extractPlatformName(path string) string {
	// Remove leading slash
	path = strings.TrimPrefix(path, "/")

	// Split by slash
	parts := strings.Split(path, "/")

	// First part is the platform name
	if len(parts) > 0 {
		// Special case for Telegram with token in the URL
		if parts[0] == "telegram" && len(parts) > 1 && parts[1] == "incoming" {
			return "telegram"
		}
		return parts[0]
	}

	return ""
}

// Handle message processing
func (a *App) handleMessage(item queue.Item) {
	// Get platform
	p, err := platform.Get(item.Platform)
	if err != nil {
		a.logger.Error("Error getting platform", "error", err)
		return
	}

	// Create a new request with the body
	bodyJSON, ok := item.Request["json"].(json.RawMessage)
	if !ok {
		a.logger.Error("Invalid JSON in request")
		return
	}

	reqPath, ok := item.Request["path"].(string)
	if !ok {
		a.logger.Error("Invalid path in request")
		return
	}

	req, err := http.NewRequest("POST", reqPath, strings.NewReader(string(bodyJSON)))
	if err != nil {
		a.logger.Error("Error creating request", "error", err)
		return
	}

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

	// Parse message
	message, err := p.ParseIncomingMessage(req)
	if err != nil {
		a.logger.Error("Error parsing message", "error", err)
		return
	}

	// Skip if message is from a bot
	if message == nil || message.FromBot {
		return
	}

	// Get or create channel
	channel, err := a.db.GetChannelByPlatform(item.Platform, message.Chat)
	if err == db.ErrNotFound {
		channel, err = a.db.CreateChannel(item.Platform, message.Chat, false, message.Channel.ChannelRaw)
		if err != nil {
			a.logger.Error("Error creating channel", "error", err)
			return
		}
	} else if err != nil {
		a.logger.Error("Error getting channel", "error", err)
		return
	}

	// Skip if channel is disabled
	if !channel.Enabled {
		return
	}

	// Process message with plugins
	for pluginID, channelPlugin := range channel.Plugins {
		if !channel.HasEnabledPlugin(pluginID) {
			continue
		}

		// Get plugin
		p, err := plugin.Get(pluginID)
		if err != nil {
			a.logger.Error("Error getting plugin", "error", err)
			continue
		}

		// Process message
		responses := p.OnMessage(message, channelPlugin.Config)

		// Send responses
		platform, err := platform.Get(item.Platform)
		if err != nil {
			a.logger.Error("Error getting platform", "error", err)
			continue
		}

		for _, response := range responses {
			if err := platform.SendMessage(response); err != nil {
				a.logger.Error("Error sending message", "error", err)
			}
		}
	}
}