package main

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

	"github.com/tarm/serial"

	log "github.com/sirupsen/logrus"
	yaml "gopkg.in/yaml.v3"

	"gitea.futuresens.co.uk/futuresens/hardlink/dispenser"
	"gitea.futuresens.co.uk/futuresens/hardlink/handlers"
	"gitea.futuresens.co.uk/futuresens/hardlink/lockserver"
	"gitea.futuresens.co.uk/futuresens/hardlink/printer"
)

const (
	buildVersion = "1.0.27"
	serviceName  = "hardlink"
)

// configRec holds values from config.yml.
type configRec struct {
	Port           int    `yaml:"port"`
	LockserverUrl  string `yaml:"lockservUrl"`
	LockType       string `yaml:"lockType"`
	EncoderAddress string `yaml:"encoderAddr"`
	Cert           string `yaml:"cert"`
	DispenserPort  string `yaml:"dispensPort"`
	DispenserAdrr  string `yaml:"dispensAddr"`
	PrinterName    string `yaml:"printerName"`
	LogDir         string `yaml:"logdir"`
	IsPayment      bool   `yaml:"isPayment"`
	TestMode       bool   `yaml:"testMode"`
}

func main() {
	// Load config
	config := readConfig()
	printer.Layout = readTicketLayout()
	printer.PrinterName = config.PrinterName
	lockserver.Cert = config.Cert
	lockserver.LockServerURL = config.LockserverUrl
	dispHandle := &serial.Port{}

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

	// Initialize dispenser
	if !config.TestMode {
		dispenser.SerialPort = config.DispenserPort
		dispenser.Address = []byte(config.DispenserAdrr)
		dispHandle, err = dispenser.InitializeDispenser()
		if err != nil {
			handlers.FatalError(err)
		}
		defer dispHandle.Close()

		status, err := dispenser.CheckDispenserStatus(dispHandle)
		if err != nil {
			if len(status) == 0 {
				err = fmt.Errorf("%s; wrong dispenser address: %s", err, config.DispenserAdrr)
				handlers.FatalError(err)
			} else {
				fmt.Println(status)
				fmt.Println(err.Error())
			}
		}
		log.Infof("Dispenser initialized on port %s, %s", config.DispenserPort, status)
	}

	// Test lock-server connection
	switch strings.ToLower(config.LockType) {
	case lockserver.TLJ:

	default:
		lockConn, err := lockserver.InitializeServerConnection(config.LockserverUrl)
		if err != nil {
			fmt.Println(err.Error())
			log.Errorf(err.Error())
		} else {
			fmt.Printf("Connected to the lock server successfuly at %s\n", config.LockserverUrl)
			log.Infof("Connected to the lock server successfuly at %s", config.LockserverUrl)
			lockConn.Close()
		}
	}

	if config.IsPayment {
		fmt.Println("Payment processing is enabled")
		log.Info("Payment processing is enabled")
		startChipDnaClient()
	} else {
		fmt.Println("Payment processing is disabled")
		log.Info("Payment processing is disabled")
	}

	// Create App and wire routes
	app := handlers.NewApp(dispHandle, config.LockType, config.EncoderAddress, config.IsPayment)

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

	addr := fmt.Sprintf(":%d", config.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 {
		handlers.FatalError(err)
	}
}

// setupLogging ensures log directory, opens log file, and configures logrus.
// Returns the *os.File so caller can defer its Close().
func setupLogging(logDir string) (*os.File, error) {
	fileName := logDir + serviceName + ".log"
	f, err := os.OpenFile(fileName, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0666)
	if err != nil {
		return nil, fmt.Errorf("open log file: %w", err)
	}

	log.SetOutput(f)
	log.SetFormatter(&log.JSONFormatter{
		TimestampFormat: time.RFC3339,
	})
	log.SetLevel(log.InfoLevel)

	log.WithFields(log.Fields{
		"buildVersion": buildVersion,
	}).Info("Logging initialized")

	return f, nil
}

// readConfig reads config.yml and applies defaults.
func readConfig() configRec {
	var cfg configRec
	const configName = "config.yml"
	defaultPort := 9091
	sep := string(os.PathSeparator)

	data, err := os.ReadFile(configName)
	if err != nil {
		log.Warnf("ReadConfig %s: %v", configName, err)
	} else if err := yaml.Unmarshal(data, &cfg); err != nil {
		log.Warnf("Unmarshal config: %v", err)
	}

	if cfg.Port == 0 {
		cfg.Port = defaultPort
	}

	if cfg.LockType == "" {
		err = fmt.Errorf("LockType is required in %s", configName)
		handlers.FatalError(err)
	}
	cfg.LockType = strings.ToLower(cfg.LockType)

	if cfg.LogDir == "" {
		cfg.LogDir = "./logs" + sep
	} else if !strings.HasSuffix(cfg.LogDir, sep) {
		cfg.LogDir += sep
	}
	return cfg
}

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

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

	// 2) Unmarshal into your struct
	if err := xml.Unmarshal(data, &layout); err != nil {
		handlers.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 {
		handlers.FatalError(err)
	}

	// Restart loop
	go func() {
		for {
			err := cmd.Wait()
			if err != nil {
				log.Errorf("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")
			}
		}
	}()

	// 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)
	}()
}