package main

import (
	"context"
	"encoding/xml"
	"fmt"
	"net/http"
	"os"
	"os/exec"
	"os/signal"
	"strings"
	"syscall"
	"time"

	"github.com/tarm/serial"

	log "github.com/sirupsen/logrus"

	"gitea.futuresens.co.uk/futuresens/hardlink/bootstrap"
	"gitea.futuresens.co.uk/futuresens/hardlink/config"
	"gitea.futuresens.co.uk/futuresens/hardlink/dispenser"
	"gitea.futuresens.co.uk/futuresens/hardlink/errorhandlers"
	"gitea.futuresens.co.uk/futuresens/hardlink/handlers"
	"gitea.futuresens.co.uk/futuresens/hardlink/lockserver"
	"gitea.futuresens.co.uk/futuresens/hardlink/logging"
	"gitea.futuresens.co.uk/futuresens/hardlink/mail"
	"gitea.futuresens.co.uk/futuresens/hardlink/payment"
	"gitea.futuresens.co.uk/futuresens/hardlink/printer"
)

const (
	buildVersion     = "1.2.5"
	serviceName      = "hardlink"
	pollingFrequency = 8 * time.Second
)

func main() {
	// Load config
	cfg := config.ReadHardlinkConfig()
	printer.Layout = readTicketLayout()
	printer.PrinterName = cfg.PrinterName
	lockserver.Cert = cfg.Cert
	lockserver.LockServerURL = cfg.LockserverUrl
	mail.SendErrorEmails = cfg.SendErrorEmails

	// Root context for background goroutines
	// rootCtx, rootCancel := context.WithCancel(context.Background())
	// defer rootCancel()

	var (
		dispPort       *serial.Port
		disp           *dispenser.Client
		cardWellStatus string
	)

	// Setup logging and get file handle
	logFile, err := logging.SetupLogging(cfg.LogDir, serviceName, buildVersion)
	if err != nil {
		log.Printf("Failed to set up logging: %v\n", err)
	}
	if logFile != nil {
		defer logFile.Close()
	}

	// Initialize dispenser
	if !cfg.TestMode {
		dispenser.SerialPort = cfg.DispenserPort
		dispenser.Address = []byte(cfg.DispenserAdrr)

		dispPort, err = dispenser.InitializeDispenser()
		if err != nil {
			mail.SendEmailOnError(cfg.Hotel, cfg.Kiosk, "Dispenser Initialization Error", fmt.Sprintf("Failed to initialize dispenser: %v", err))
			errorhandlers.FatalError(err)
		}
		defer dispPort.Close()

		disp = dispenser.NewClient(dispPort, 32)
		defer disp.Close()

		ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
		defer cancel()

		cardWellStatus, err = disp.DispenserPrepare(ctx)
		if err != nil {
			err = fmt.Errorf("%s; wrong dispenser address: %s", err, cfg.DispenserAdrr)
			mail.SendEmailOnError(cfg.Hotel, cfg.Kiosk, "Dispenser Preparation Error", err.Error())
			errorhandlers.FatalError(err)
		}
		fmt.Println(cardWellStatus)
	}

	// Test lock-server connection
	switch strings.ToLower(cfg.LockType) {
	case lockserver.TLJ:
		// TLJ uses HTTP - skip TCP probe here
	default:
		lockConn, err := lockserver.InitializeServerConnection(cfg.LockserverUrl)
		if err != nil {
			fmt.Println(err.Error())
			log.Errorf(err.Error())
			mail.SendEmailOnError(cfg.Hotel, cfg.Kiosk, "Lock Server Connection Error", err.Error())
		} else {
			fmt.Printf("Connected to the lock server successfuly at %s\n", cfg.LockserverUrl)
			log.Infof("Connected to the lock server successfuly at %s", cfg.LockserverUrl)
			lockConn.Close()
		}
	}

	database, err := bootstrap.OpenDB(&cfg)
	if err != nil {
		log.Warnf("DB init failed: %v", err)
	}
	if database != nil {
		defer database.Close()
	}

	if cfg.IsPayment {
		fmt.Println("Payment processing is enabled")
		log.Info("Payment processing is enabled")

		startChipDnaClient()

		// check ChipDNA and PDQ status and log any errors, but continue running even if it fails
		go func() {
			time.Sleep(30 * time.Second) // give ChipDNA client a moment to start
			pdqstatus, err := payment.ReadPdqStatus(cfg.Hotel, cfg.Kiosk)
			if err != nil {
				mail.SendEmailOnError(cfg.Hotel, cfg.Kiosk, "PDQ Status Read Error", err.Error())
			} else {
				fmt.Printf("\nPDQ availabile: %v\n", pdqstatus.IsAvailable)
				log.Infof("PDQ availabile: %v", pdqstatus.IsAvailable)
			}
		}()
	} else {
		fmt.Println("Payment processing is disabled")
		log.Info("Payment processing is disabled")
	}

	// Create App and wire routes
	app := handlers.NewApp(disp, cfg.LockType, cfg.EncoderAddress, cardWellStatus, database, &cfg)

	// Update cardWellStatus when dispenser status changes
	if !cfg.TestMode && disp != nil {
		// Set initial cardWellStatus
		app.SetCardWellStatus(cardWellStatus)

		// Set up callback to update cardWellStatus when dispenser status changes
		disp.OnStockUpdate(func(stock string) {
			app.SetCardWellStatus(stock)
		})

		// Start polling for dispenser status every 10 seconds
		disp.StartPolling(pollingFrequency)
	}

	mux := http.NewServeMux()
	app.RegisterRoutes(mux)

	addr := fmt.Sprintf(":%d", cfg.Port)
	log.Infof("Starting HTTP server on http://localhost%s", addr)
	fmt.Printf("Starting HTTP server on http://localhost%s", addr)

	if err := http.ListenAndServe(addr, mux); err != nil {
		errorhandlers.FatalError(err)
	}
}

func readTicketLayout() printer.LayoutOptions {
	const layoutName = "TicketLayout.xml"
	var layout printer.LayoutOptions

	// 1) Read the file
	data, err := os.ReadFile(layoutName)
	if err != nil {
		errorhandlers.FatalError(fmt.Errorf("failed to read %s: %v", layoutName, err))
	}

	// 2) Unmarshal into your struct
	if err := xml.Unmarshal(data, &layout); err != nil {
		errorhandlers.FatalError(fmt.Errorf("failed to parse %s: %v", layoutName, err))
	}

	return layout
}

func startChipDnaClient() {
	startClient := func() (*exec.Cmd, error) {
		cmd := exec.Command("./ChipDNAClient/ChipDnaClient.exe")
		err := cmd.Start()
		if err != nil {
			return nil, fmt.Errorf("failed to start ChipDnaClient: %v", err)
		}
		log.Infof("ChipDnaClient started with PID %d", cmd.Process.Pid)
		return cmd, nil
	}

	cmd, err := startClient()
	if err != nil {
		errorhandlers.FatalError(err)
	}

	// Restart loop
	go func() {
		for {
			err := cmd.Wait()
			if err != nil {
				log.Errorf("ChipDnaClient exited unexpectedly: %v", err)
				fmt.Printf("ChipDnaClient exited unexpectedly: %v", err)
				time.Sleep(2 * time.Second)
				cmd, err = startClient()
				if err != nil {
					log.Errorf("Restart failed: %v", err)
					return
				}
				log.Info("ChipDnaClient restarted successfully")
				fmt.Printf("ChipDnaClient restarted successfully")
			}
		}
	}()

	// Handle shutdown signals
	sigs := make(chan os.Signal, 1)
	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
	go func() {
		<-sigs
		log.Info("Shutting down...")
		if cmd.Process != nil {
			log.Info("Sending SIGTERM to ChipDnaClient...")
			_ = cmd.Process.Signal(syscall.SIGTERM)
			// wait up to 5s for graceful shutdown
			done := make(chan error, 1)
			go func() { done <- cmd.Wait() }()
			select {
			case <-time.After(5 * time.Second):
				log.Warn("ChipDnaClient did not exit in time, killing...")
				_ = cmd.Process.Kill()
			case err := <-done:
				log.Infof("ChipDnaClient exited cleanly: %v", err)
			}
		}
		os.Exit(0)
	}()
}