package flexradio

import (
	"bufio"
	"fmt"
	"log"
	"net"
	"strconv"
	"strings"
	"sync"
	"time"
	"unicode"
)

type Client struct {
	host string
	port int

	conn    net.Conn
	reader  *bufio.Reader
	connMu  sync.Mutex
	writeMu sync.Mutex

	lastStatus *Status
	statusMu   sync.RWMutex

	cmdSeq   int
	cmdSeqMu sync.Mutex

	running  bool
	stopChan chan struct{}

	reconnectInterval time.Duration
	reconnectAttempts int
	maxReconnectDelay time.Duration

	radioInfo      map[string]string
	radioInfoMu    sync.RWMutex
	lastInfoCheck  time.Time
	infoCheckTimer *time.Timer

	activeSlices   []int
	activeSlicesMu sync.RWMutex
	sliceListTimer *time.Timer

	onFrequencyChange    func(freqMHz float64)
	checkTransmitAllowed func() bool
}

func New(host string, port int) *Client {
	return &Client{
		host:              host,
		port:              port,
		stopChan:          make(chan struct{}),
		reconnectInterval: 5 * time.Second,
		maxReconnectDelay: 60 * time.Second,
		radioInfo:         make(map[string]string),
		activeSlices:      []int{},
		lastStatus: &Status{
			Connected: false,
			RadioOn:   false,
		},
	}
}

// SetReconnectInterval sets the reconnection interval
func (c *Client) SetReconnectInterval(interval time.Duration) {
	c.reconnectInterval = interval
}

// SetMaxReconnectDelay sets the maximum delay for exponential backoff
func (c *Client) SetMaxReconnectDelay(delay time.Duration) {
	c.maxReconnectDelay = delay
}

// SetFrequencyChangeCallback sets the callback function called when frequency changes
func (c *Client) SetFrequencyChangeCallback(callback func(freqMHz float64)) {
	c.onFrequencyChange = callback
}

// SetTransmitCheckCallback sets the callback to check if transmit is allowed
func (c *Client) SetTransmitCheckCallback(callback func() bool) {
	c.checkTransmitAllowed = callback
}

func (c *Client) Connect() error {
	c.connMu.Lock()
	defer c.connMu.Unlock()

	if c.conn != nil {
		return nil
	}

	addr := fmt.Sprintf("%s:%d", c.host, c.port)
	log.Printf("FlexRadio: Connecting to %s...", addr)

	conn, err := net.DialTimeout("tcp", addr, 5*time.Second)
	if err != nil {
		return fmt.Errorf("failed to connect: %w", err)
	}

	c.conn = conn
	c.reader = bufio.NewReader(conn)
	c.reconnectAttempts = 0

	log.Println("FlexRadio: TCP connection established")
	return nil
}

func (c *Client) Start() error {
	if c.running {
		return nil
	}

	// Try initial connection
	if err := c.Connect(); err != nil {
		log.Printf("FlexRadio: Initial connection failed: %v", err)
	}

	// Update connected status
	c.statusMu.Lock()
	if c.lastStatus != nil {
		c.lastStatus.Connected = (c.conn != nil)
		c.lastStatus.RadioOn = false
	}
	c.statusMu.Unlock()

	c.running = true

	// Start message listener
	go c.messageLoop()

	// Start reconnection monitor
	go c.reconnectionMonitor()

	// Start radio status checker
	go c.radioStatusChecker()

	// Start slice list checker
	go c.sliceListChecker()

	// Try to get initial radio info and subscribe to slices
	if c.conn != nil {
		go func() {
			time.Sleep(500 * time.Millisecond)
			c.SendInfo()

			time.Sleep(500 * time.Millisecond)
			c.SendSliceList()

			time.Sleep(500 * time.Millisecond)
			c.SubscribeToSlices()
		}()
	}

	return nil
}

func (c *Client) Stop() {
	if !c.running {
		return
	}

	c.running = false
	close(c.stopChan)

	// Stop timers
	if c.infoCheckTimer != nil {
		c.infoCheckTimer.Stop()
	}
	if c.sliceListTimer != nil {
		c.sliceListTimer.Stop()
	}

	c.connMu.Lock()
	if c.conn != nil {
		c.conn.Close()
		c.conn = nil
		c.reader = nil
	}
	c.connMu.Unlock()

	// Update status
	c.statusMu.Lock()
	if c.lastStatus != nil {
		c.lastStatus.Connected = false
		c.lastStatus.RadioOn = false
		c.lastStatus.RadioInfo = "Disconnected"
		c.lastStatus.ActiveSlices = 0
		c.lastStatus.Frequency = 0
		c.lastStatus.Mode = ""
		c.lastStatus.Tx = false
	}
	c.statusMu.Unlock()
}

// Helper functions for common commands
func (c *Client) SendInfo() error {
	return c.sendCommand("info")
}

func (c *Client) SendSliceList() error {
	return c.sendCommand("slice list")
}

func (c *Client) SubscribeToSlices() error {
	return c.sendCommand("sub slice all")
}

func (c *Client) sendCommand(cmd string) error {
	c.writeMu.Lock()
	defer c.writeMu.Unlock()

	c.connMu.Lock()
	conn := c.conn
	c.connMu.Unlock()

	if conn == nil {
		return fmt.Errorf("not connected")
	}

	seq := c.getNextSeq()
	fullCmd := fmt.Sprintf("C%d|%s\n", seq, cmd)

	log.Printf("FlexRadio TX: %s", strings.TrimSpace(fullCmd))

	_, err := conn.Write([]byte(fullCmd))
	if err != nil {
		// Mark connection as broken
		c.connMu.Lock()
		if c.conn != nil {
			c.conn.Close()
			c.conn = nil
			c.reader = nil
		}
		c.connMu.Unlock()

		// Update status
		c.statusMu.Lock()
		if c.lastStatus != nil {
			c.lastStatus.Connected = false
			c.lastStatus.RadioOn = false
			c.lastStatus.RadioInfo = "Connection lost"
		}
		c.statusMu.Unlock()

		return fmt.Errorf("failed to send command: %w", err)
	}

	return nil
}

func (c *Client) getNextSeq() int {
	c.cmdSeqMu.Lock()
	defer c.cmdSeqMu.Unlock()
	c.cmdSeq++
	return c.cmdSeq
}

func (c *Client) messageLoop() {
	log.Println("FlexRadio: Message loop started")

	for c.running {
		c.connMu.Lock()
		if c.conn == nil || c.reader == nil {
			c.connMu.Unlock()
			time.Sleep(1 * time.Second)
			continue
		}

		c.conn.SetReadDeadline(time.Now().Add(2 * time.Second))
		line, err := c.reader.ReadString('\n')
		c.connMu.Unlock()

		if err != nil {
			if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
				continue
			}

			log.Printf("FlexRadio: Read error: %v", err)

			c.connMu.Lock()
			if c.conn != nil {
				c.conn.Close()
				c.conn = nil
				c.reader = nil
			}
			c.connMu.Unlock()

			c.statusMu.Lock()
			if c.lastStatus != nil {
				c.lastStatus.Connected = false
				c.lastStatus.RadioOn = false
				c.lastStatus.RadioInfo = "Connection lost"
			}
			c.statusMu.Unlock()
			continue
		}

		line = strings.TrimSpace(line)
		if line == "" {
			continue
		}

		c.handleMessage(line)
	}

	log.Println("FlexRadio: Message loop stopped")
}

// Message handling - SIMPLIFIED VERSION
func (c *Client) handleMessage(msg string) {
	msg = strings.TrimSpace(msg)
	if msg == "" {
		return
	}

	// DEBUG: Log tous les messages reçus
	log.Printf("FlexRadio RAW: %s", msg)

	// Router selon le premier caractère
	switch msg[0] {
	case 'R': // Réponse à une commande
		c.handleCommandResponse(msg)
	case 'S': // Message de statut
		c.handleStatusMessage(msg)
	case 'V': // Version/Handle
		log.Printf("FlexRadio: Version/Handle: %s", msg)
	case 'M': // Message général
		log.Printf("FlexRadio: Message: %s", msg)
	default:
		log.Printf("FlexRadio: Unknown message type: %s", msg)
	}
}

func (c *Client) handleCommandResponse(msg string) {
	// Format: R<seq>|<status>|<data>
	parts := strings.SplitN(msg, "|", 3)
	if len(parts) < 3 {
		log.Printf("FlexRadio: Malformed response: %s", msg)
		return
	}

	seqStr := strings.TrimPrefix(parts[0], "R")
	status := parts[1]
	data := parts[2]

	seq, _ := strconv.Atoi(seqStr)

	if status != "0" {
		log.Printf("FlexRadio: Command error (seq=%d): %s", seq, msg)
		return
	}

	log.Printf("FlexRadio: Command success (seq=%d)", seq)

	// Identifier le type de réponse par son contenu
	switch {
	case strings.Contains(data, "model="):
		c.parseInfoResponse(data)

	case isSliceListResponse(data):
		c.parseSliceListResponse(data)

	default:
		log.Printf("FlexRadio: Generic response: %s", data)
	}
}

func isSliceListResponse(data string) bool {
	data = strings.TrimSpace(data)
	if data == "" {
		return true
	}

	for _, char := range data {
		if !unicode.IsDigit(char) && char != ' ' {
			return false
		}
	}
	return true
}

func (c *Client) handleStatusMessage(msg string) {
	parts := strings.SplitN(msg, "|", 2)
	if len(parts) < 2 {
		return
	}

	handle := parts[0][1:]
	data := parts[1]

	statusMap := make(map[string]string)
	pairs := strings.Fields(data)

	for _, pair := range pairs {
		if kv := strings.SplitN(pair, "=", 2); len(kv) == 2 {
			statusMap[kv[0]] = kv[1]
		}
	}

	switch {
	case strings.Contains(msg, "interlock"):
		c.handleInterlockStatus(handle, statusMap)

	case strings.Contains(msg, "slice"):
		c.handleSliceStatus(handle, statusMap)

	case strings.Contains(msg, "radio"):
		c.handleRadioStatus(handle, statusMap)

	default:
		log.Printf("FlexRadio: Unknown status (handle=%s): %s", handle, msg)
	}
}

func (c *Client) handleInterlockStatus(handle string, statusMap map[string]string) {
	c.statusMu.Lock()
	defer c.statusMu.Unlock()

	if state, ok := statusMap["state"]; ok {
		c.lastStatus.Tx = (state == "TRANSMITTING" || state == "TUNE")
		log.Printf("FlexRadio: Interlock state=%s, TX=%v", state, c.lastStatus.Tx)
	}
}

func (c *Client) handleSliceStatus(handle string, statusMap map[string]string) {
	c.statusMu.Lock()
	defer c.statusMu.Unlock()

	// Quand on reçoit un message de slice, on a au moins une slice active
	c.lastStatus.ActiveSlices = 1

	if rfFreq, ok := statusMap["RF_frequency"]; ok {
		if freq, err := strconv.ParseFloat(rfFreq, 64); err == nil && freq > 0 {
			c.lastStatus.Frequency = freq
			c.lastStatus.RadioInfo = fmt.Sprintf("Active on %.3f MHz", freq)

			if c.onFrequencyChange != nil {
				go c.onFrequencyChange(freq)
			}
		} else if freq == 0 {
			// Fréquence 0 dans le message de slice = slice inactive
			c.lastStatus.Frequency = 0
			c.lastStatus.RadioInfo = "Slice inactive"
		}
	}

	if mode, ok := statusMap["mode"]; ok {
		c.lastStatus.Mode = mode
	}

	if tx, ok := statusMap["tx"]; ok {
		c.lastStatus.Tx = (tx == "1")
	}
}

func (c *Client) handleRadioStatus(handle string, statusMap map[string]string) {
	if slices, ok := statusMap["slices"]; ok {
		if num, err := strconv.Atoi(slices); err == nil {
			c.statusMu.Lock()
			c.lastStatus.NumSlices = num
			c.statusMu.Unlock()
		}
	}
}

func (c *Client) parseInfoResponse(data string) {
	log.Printf("FlexRadio: Parsing info response: %s", data)

	pairs := []string{}
	current := ""
	inQuotes := false

	for _, char := range data {
		if char == '"' {
			inQuotes = !inQuotes
		}
		if char == ',' && !inQuotes {
			pairs = append(pairs, strings.TrimSpace(current))
			current = ""
		} else {
			current += string(char)
		}
	}
	if current != "" {
		pairs = append(pairs, strings.TrimSpace(current))
	}

	c.radioInfoMu.Lock()
	c.radioInfo = make(map[string]string)

	for _, pair := range pairs {
		kv := strings.SplitN(pair, "=", 2)
		if len(kv) == 2 {
			key := strings.TrimSpace(kv[0])
			value := strings.TrimSpace(kv[1])

			if len(value) >= 2 && value[0] == '"' && value[len(value)-1] == '"' {
				value = value[1 : len(value)-1]
			}

			c.radioInfo[key] = value
		}
	}

	c.radioInfoMu.Unlock()

	c.updateRadioStatus(true, "Radio is on")

	go func() {
		time.Sleep(300 * time.Millisecond)
		c.SendSliceList()
	}()
}

func (c *Client) parseSliceListResponse(data string) {
	slices := []int{}

	if strings.TrimSpace(data) != "" {
		parts := strings.Fields(data)
		for _, part := range parts {
			if sliceNum, err := strconv.Atoi(part); err == nil {
				slices = append(slices, sliceNum)
			}
		}
	}

	c.activeSlicesMu.Lock()
	c.activeSlices = slices
	c.activeSlicesMu.Unlock()

	c.statusMu.Lock()
	if c.lastStatus != nil {
		c.lastStatus.ActiveSlices = len(slices)

		// NE PAS effacer la fréquence ici !
		// La fréquence est gérée par handleSliceStatus

		// Seulement mettre à jour RadioInfo si vraiment pas de slices
		if len(slices) == 0 && c.lastStatus.Frequency == 0 {
			c.lastStatus.RadioInfo = "Radio is on without any active slice"
		} else if len(slices) == 0 && c.lastStatus.Frequency > 0 {
			// Cas spécial : fréquence mais pas de slice dans la liste
			// Peut arriver temporairement, garder l'info actuelle
			c.lastStatus.RadioInfo = fmt.Sprintf("Active on %.3f MHz", c.lastStatus.Frequency)
		}
	}
	c.statusMu.Unlock()

	log.Printf("FlexRadio: Active slices updated: %v (total: %d)", slices, len(slices))
}

func (c *Client) updateRadioStatus(isOn bool, info string) {
	c.statusMu.Lock()
	defer c.statusMu.Unlock()

	if c.lastStatus != nil {
		c.lastStatus.RadioOn = isOn
		c.lastStatus.RadioInfo = info

		c.radioInfoMu.RLock()
		if callsign, ok := c.radioInfo["callsign"]; ok {
			c.lastStatus.Callsign = callsign
		}
		if model, ok := c.radioInfo["model"]; ok {
			c.lastStatus.Model = model
		}
		if softwareVer, ok := c.radioInfo["software_ver"]; ok {
			c.lastStatus.SoftwareVer = softwareVer
		}
		if numSlicesStr, ok := c.radioInfo["num_slice"]; ok {
			if numSlices, err := strconv.Atoi(numSlicesStr); err == nil {
				c.lastStatus.NumSlices = numSlices
			}
		}
		c.radioInfoMu.RUnlock()

		if isOn && c.lastStatus.Frequency == 0 && c.lastStatus.ActiveSlices == 0 {
			c.lastStatus.RadioInfo = "Radio is on without any active slice"
		}
	}
}

func (c *Client) reconnectionMonitor() {
	log.Println("FlexRadio: Reconnection monitor started")

	for c.running {
		c.connMu.Lock()
		connected := (c.conn != nil)
		c.connMu.Unlock()

		if !connected {
			c.reconnectAttempts++

			delay := c.calculateReconnectDelay()

			log.Printf("FlexRadio: Attempting to reconnect in %v (attempt %d)...", delay, c.reconnectAttempts)

			select {
			case <-time.After(delay):
				if err := c.reconnect(); err != nil {
					log.Printf("FlexRadio: Reconnection attempt %d failed: %v", c.reconnectAttempts, err)
				} else {
					log.Printf("FlexRadio: Reconnected successfully on attempt %d", c.reconnectAttempts)
					c.reconnectAttempts = 0

					go func() {
						time.Sleep(500 * time.Millisecond)
						c.SendInfo()
					}()
				}
			case <-c.stopChan:
				return
			}
		} else {
			select {
			case <-time.After(10 * time.Second):
			case <-c.stopChan:
				return
			}
		}
	}
}

func (c *Client) calculateReconnectDelay() time.Duration {
	delay := c.reconnectInterval

	if c.reconnectAttempts > 1 {
		multiplier := 1 << (c.reconnectAttempts - 1)
		delay = c.reconnectInterval * time.Duration(multiplier)

		if delay > c.maxReconnectDelay {
			delay = c.maxReconnectDelay
		}
	}

	return delay
}

func (c *Client) reconnect() error {
	c.connMu.Lock()
	defer c.connMu.Unlock()

	// Close existing connection if any
	if c.conn != nil {
		c.conn.Close()
		c.conn = nil
		c.reader = nil
	}

	addr := fmt.Sprintf("%s:%d", c.host, c.port)
	log.Printf("FlexRadio: Reconnecting to %s...", addr)

	conn, err := net.DialTimeout("tcp", addr, 5*time.Second)
	if err != nil {
		c.statusMu.Lock()
		if c.lastStatus != nil {
			c.lastStatus.Connected = false
			c.lastStatus.RadioOn = false
			c.lastStatus.RadioInfo = "Disconnected"
		}
		c.statusMu.Unlock()
		return fmt.Errorf("reconnect failed: %w", err)
	}

	c.conn = conn
	c.reader = bufio.NewReader(conn)

	c.statusMu.Lock()
	if c.lastStatus != nil {
		c.lastStatus.Connected = true
		c.lastStatus.RadioInfo = "TCP connected, checking radio..."
	}
	c.statusMu.Unlock()

	log.Println("FlexRadio: TCP connection reestablished")
	return nil
}

func (c *Client) radioStatusChecker() {
	c.infoCheckTimer = time.NewTimer(10 * time.Second)

	for c.running {
		select {
		case <-c.infoCheckTimer.C:
			c.SendInfo()
			c.infoCheckTimer.Reset(10 * time.Second)
		case <-c.stopChan:
			return
		}
	}
}

func (c *Client) sliceListChecker() {
	c.sliceListTimer = time.NewTimer(10 * time.Second)

	for c.running {
		select {
		case <-c.sliceListTimer.C:
			if c.IsRadioOn() {
				c.SendSliceList()
			}
			c.sliceListTimer.Reset(10 * time.Second)
		case <-c.stopChan:
			return
		}
	}
}

func (c *Client) GetStatus() (*Status, error) {
	c.statusMu.RLock()
	defer c.statusMu.RUnlock()

	if c.lastStatus == nil {
		return &Status{
			Connected: false,
			RadioOn:   false,
			RadioInfo: "Not initialized",
		}, nil
	}

	status := *c.lastStatus
	return &status, nil
}

// IsRadioOn returns true if radio is powered on and responding
func (c *Client) IsRadioOn() bool {
	c.statusMu.RLock()
	defer c.statusMu.RUnlock()

	if c.lastStatus == nil {
		return false
	}

	return c.lastStatus.RadioOn
}