package arduino

import (
	"bufio"
	"github.com/cyrilix/robocar-arduino/pkg/tools"
	"github.com/cyrilix/robocar-protobuf/go/events"
	mqtt "github.com/eclipse/paho.mqtt.golang"
	"github.com/tarm/serial"
	"go.uber.org/zap"
	"google.golang.org/protobuf/proto"
	"io"
	"regexp"
	"strconv"
	"strings"
	"sync"
	"time"
)

const (
	MinPwmThrottle = 972.0
	MaxPwmThrottle = 1954.0
)

var (
	serialLineRegex    = regexp.MustCompile(`(?P<timestamp>\d+),(?P<channel_1>\d+),(?P<channel_2>\d+),(?P<channel_3>\d+),(?P<channel_4>\d+),(?P<channel_5>\d+),(?P<channel_6>-?\d+),(?P<channel_7>\d+),(?P<channel_8>\d+),(?P<channel_9>\d+),(?P<frequency>\d+)`)
	DefaultPwmThrottle = PWMConfig{
		Min:    MinPwmThrottle,
		Max:    MaxPwmThrottle,
		Middle: MinPwmThrottle + (MaxPwmThrottle-MinPwmThrottle)/2,
	}
)

type Part struct {
	client                                                                                 mqtt.Client
	throttleTopic, steeringTopic, driveModeTopic, switchRecordTopic, throttleFeedbackTopic string
	maxThrottleCtrlTopic                                                                   string
	pubFrequency                                                                           float64
	serial                                                                                 io.Reader
	mutex                                                                                  sync.Mutex
	steering                                                                               float32
	throttle                                                                               float32
	throttleFeedback                                                                       float32
	maxThrottleCtrl                                                                        float32
	ctrlRecord                                                                             bool
	driveMode                                                                              events.DriveMode
	cancel                                                                                 chan interface{}

	pwmSteeringConfig        *PWMConfig
	pwmThrottleConfig        *PWMConfig
	pwmMaxThrottleCtrlConfig *PWMConfig

	throttleFeedbackThresholds *tools.ThresholdConfig
}

type PWMConfig struct {
	Min    int
	Max    int
	Middle int
}

func NewPWMConfig(min, max int) *PWMConfig {
	return &PWMConfig{
		Min:    min,
		Max:    max,
		Middle: min + (max-min)/2,
	}
}

func NewAsymetricPWMConfig(min, max, middle int) *PWMConfig {
	c := NewPWMConfig(min, max)
	c.Middle = middle
	return c
}

type Option func(p *Part)

func WithThrottleConfig(throttleConfig *PWMConfig) Option {
	return func(p *Part) {
		p.pwmThrottleConfig = throttleConfig
	}
}

func WithSteeringConfig(steeringConfig *PWMConfig) Option {
	return func(p *Part) {
		p.pwmSteeringConfig = steeringConfig
	}
}

func WithMaxThrottleCtrl(throttleCtrl *PWMConfig) Option {
	return func(p *Part) {
		p.pwmMaxThrottleCtrlConfig = throttleCtrl
	}
}

func WithThrottleFeedbackConfig(filename string) Option {
	return func(p *Part) {
		if filename == "" {
			p.throttleFeedbackThresholds = tools.NewThresholdConfig()
			return
		}
		tc, err := tools.NewThresholdConfigFromJson(filename)
		if err != nil {
			zap.S().Panicf("unable to load ThresholdConfig from file %v: %v", filename, err)
		}
		p.throttleFeedbackThresholds = tc

	}
}

func NewPart(client mqtt.Client, name string, baud int, throttleTopic, steeringTopic, driveModeTopic,
	switchRecordTopic, throttleFeedbackTopic, maxThrottleCtrlTopic string, pubFrequency float64, options ...Option) *Part {
	c := &serial.Config{Name: name, Baud: baud}
	s, err := serial.OpenPort(c)
	if err != nil {
		zap.S().Panicw("unable to open serial port: %v", err)
	}
	p := &Part{
		client:                client,
		serial:                s,
		throttleTopic:         throttleTopic,
		steeringTopic:         steeringTopic,
		driveModeTopic:        driveModeTopic,
		switchRecordTopic:     switchRecordTopic,
		throttleFeedbackTopic: throttleFeedbackTopic,
		maxThrottleCtrlTopic:  maxThrottleCtrlTopic,
		pubFrequency:          pubFrequency,
		driveMode:             events.DriveMode_INVALID,
		cancel:                make(chan interface{}),

		pwmSteeringConfig:        &DefaultPwmThrottle,
		pwmThrottleConfig:        &DefaultPwmThrottle,
		pwmMaxThrottleCtrlConfig: &DefaultPwmThrottle,

		throttleFeedbackThresholds: tools.NewThresholdConfig(),
	}

	for _, o := range options {
		o(p)
	}
	return p
}

func (a *Part) Start() error {
	zap.S().Info("start arduino part")
	go a.publishLoop()
	for {
		buff := bufio.NewReader(a.serial)
		line, err := buff.ReadString('\n')
		if err == io.EOF || line == "" {
			zap.S().Error("remote connection closed")
			break
		}

		zap.L().Debug("raw line: %s", zap.String("raw", line))
		if !serialLineRegex.MatchString(line) {
			zap.S().Errorf("invalid line: '%v'", line)
			continue
		}
		values := strings.Split(strings.TrimSuffix(strings.TrimSuffix(line, "\n"), "\r"), ",")

		a.updateValues(values)
	}
	return nil
}

func (a *Part) updateValues(values []string) {
	a.mutex.Lock()
	defer a.mutex.Unlock()
	a.processChannel1(values[1])
	a.processChannel2(values[2])
	a.processChannel3(values[3])
	a.processChannel4(values[4])
	a.processChannel5(values[5])
	a.processChannel6(values[6])
	a.processChannel7(values[7])
	a.processChannel8(values[8])
	a.processChannel9(values[9])
}

func (a *Part) Stop() {
	zap.S().Info("stop ArduinoPart")
	close(a.cancel)
	switch s := a.serial.(type) {
	case io.ReadCloser:
		if err := s.Close(); err != nil {
			zap.S().Fatalf("unable to close serial port: %v", err)
		}
	}
}

func (a *Part) processChannel1(v string) {
	zap.L().Debug("process new value for steering on channel1", zap.String("value", v))
	value, err := strconv.Atoi(v)
	if err != nil {
		zap.S().Errorf("invalid steering value for channel1, should be an int: %v", err)
	}
	a.steering = convertPwmToPercent(value, a.pwmSteeringConfig)
}

func convertPwmToPercent(value int, c *PWMConfig) float32 {
	if value < c.Min {
		value = c.Min
	} else if value > c.Max {
		value = c.Max
	}
	if value == c.Middle {
		return 0.
	}
	if value < c.Middle {
		return (float32(value) - float32(c.Middle)) / float32(c.Middle-c.Min)
	}
	//  middle < value < max
	return (float32(value) - float32(c.Middle)) / float32(c.Max-c.Middle)
}

func (a *Part) processChannel2(v string) {
	zap.L().Debug("process new throttle value on channel2", zap.String("value", v))
	value, err := strconv.Atoi(v)
	if err != nil {
		zap.S().Errorf("invalid throttle value for channel2, should be an int: %v", err)
	}
	if value < a.pwmThrottleConfig.Min {
		value = a.pwmThrottleConfig.Min
	} else if value > a.pwmThrottleConfig.Max {
		value = a.pwmThrottleConfig.Max
	}

	throttle := 0.
	if value > a.pwmThrottleConfig.Middle {
		throttle = (float64(value) - float64(a.pwmThrottleConfig.Middle)) / float64(a.pwmThrottleConfig.Max-a.pwmThrottleConfig.Middle)
	}
	if value < a.pwmThrottleConfig.Middle {
		throttle = -1. * (float64(a.pwmThrottleConfig.Middle) - float64(value)) / (float64(a.pwmThrottleConfig.Middle - a.pwmThrottleConfig.Min))
	}

	a.throttle = float32(throttle)
}

func (a *Part) processChannel3(v string) {
	zap.L().Debug("process new value for channel3", zap.String("value", v))

	value, err := strconv.Atoi(v)
	if err != nil {
		zap.S().Errorf("invalid steering value for channel1, should be an int: %v", err)
	}
	a.maxThrottleCtrl = (convertPwmToPercent(value, a.pwmSteeringConfig) + 1) / 2
}

func (a *Part) processChannel4(v string) {
	zap.L().Debug("process new value for channel4", zap.String("value", v))
	value, err := strconv.Atoi(v)
	if err != nil {
		zap.S().Errorf("invalid throttle value for channel2, should be an int: %v", err)
	}
	a.throttleFeedback = a.convertPwmFeedBackToPercent(value)
}

func (a *Part) processChannel5(v string) {
	zap.L().Debug("process new value for channel5", zap.String("value", v))

	value, err := strconv.Atoi(v)
	if err != nil {
		zap.S().Errorf("invalid value for channel5 'record', should be an int: %v", err)
	}

	if value < 1800 {
		if !a.ctrlRecord {
			zap.S().Infof("Update channel 5 with value %v, record: %v", true, false)
			a.ctrlRecord = true
		}
	} else {
		if a.ctrlRecord {
			zap.S().Infof("Update channel 5 with value %v, record: %v", false, true)
			a.ctrlRecord = false
		}
	}
}

func (a *Part) processChannel6(v string) {
	zap.L().Debug("process new value for channel6", zap.String("value", v))
	value, err := strconv.Atoi(v)
	if err != nil {
		zap.S().Errorf("invalid value for channel6 'drive-mode', should be an int: %v", err)
		return
	}
	if value < 0 {
		// No value, ignore it
		return
	}
	if value <= 1800 && value > 1200 {
		if a.driveMode != events.DriveMode_COPILOT {
			zap.S().Infof("Update channel 6 'drive-mode' with value %v, new user_mode: %v", value, events.DriveMode_PILOT)
			a.driveMode = events.DriveMode_COPILOT
		}
	} else if value > 1800 {
		if a.driveMode != events.DriveMode_PILOT {
			zap.S().Infof("Update channel 6 'drive-mode' with value %v, new user_mode: %v", value, events.DriveMode_PILOT)
			a.driveMode = events.DriveMode_PILOT
		}
	} else {
		if a.driveMode != events.DriveMode_USER {
			zap.S().Infof("Update channel 6 'drive-mode' with value %v, new user_mode: %v", value, events.DriveMode_USER)
		}
		a.driveMode = events.DriveMode_USER
	}
}

func (a *Part) processChannel7(v string) {
	zap.L().Debug("process new value for secondary steering on channel7", zap.String("value", v))
}

func (a *Part) processChannel8(v string) {
	zap.L().Debug("process new throttle value on channel8", zap.String("value", v))
}

func (a *Part) processChannel9(v string) {
	zap.L().Debug("process new value for channel9", zap.String("value", v))
}

func (a *Part) Throttle() float32 {
	a.mutex.Lock()
	defer a.mutex.Unlock()
	return a.throttle
}

func (a *Part) ThrottleFeedback() float32 {
	a.mutex.Lock()
	defer a.mutex.Unlock()
	return a.throttleFeedback
}

func (a *Part) MaxThrottleCtrl() float32 {
	a.mutex.Lock()
	defer a.mutex.Unlock()
	return a.maxThrottleCtrl
}

func (a *Part) Steering() float32 {
	a.mutex.Lock()
	defer a.mutex.Unlock()
	return a.steering
}

func (a *Part) DriveMode() events.DriveMode {
	a.mutex.Lock()
	defer a.mutex.Unlock()
	return a.driveMode
}

func (a *Part) SwitchRecord() bool {
	a.mutex.Lock()
	defer a.mutex.Unlock()
	return a.ctrlRecord
}

func (a *Part) publishLoop() {
	ticker := time.NewTicker(time.Second / time.Duration(int(a.pubFrequency)))

	for {
		select {
		case <-ticker.C:
			a.publishValues()
		case <-a.cancel:
			ticker.Stop()
			return
		}
	}
}

func (a *Part) publishValues() {
	a.publishThrottle()
	a.publishThrottleFeedback()
	a.publishSteering()
	a.publishDriveMode()
	a.publishSwitchRecord()
	a.publishMaxThrottleCtrl()
}

func (a *Part) publishThrottle() {
	throttle := events.ThrottleMessage{
		Throttle:   a.Throttle(),
		Confidence: 1.0,
	}
	throttleMessage, err := proto.Marshal(&throttle)
	if err != nil {
		zap.S().Errorf("unable to marshal protobuf throttle message: %v", err)
		return
	}
	zap.L().Debug("throttle channel", zap.Float32("throttle", a.throttle))
	publish(a.client, a.throttleTopic, throttleMessage)
}

func (a *Part) publishSteering() {
	steering := events.SteeringMessage{
		Steering:   a.Steering(),
		Confidence: 1.0,
	}
	steeringMessage, err := proto.Marshal(&steering)
	if err != nil {
		zap.S().Errorf("unable to marshal protobuf steering message: %v", err)
		return
	}
	zap.L().Debug("steering channel", zap.Float32("steering", a.steering))
	publish(a.client, a.steeringTopic, steeringMessage)
}

func (a *Part) publishThrottleFeedback() {
	tm := events.ThrottleMessage{
		Throttle:   a.ThrottleFeedback(),
		Confidence: 1.,
	}
	tfMessage, err := proto.Marshal(&tm)
	if err != nil {
		zap.S().Errorf("unable to marshal protobuf throttleFeedback message: %v", err)
		return
	}
	publish(a.client, a.throttleFeedbackTopic, tfMessage)
}

func (a *Part) publishMaxThrottleCtrl() {
	tm := events.ThrottleMessage{
		Throttle:   a.MaxThrottleCtrl(),
		Confidence: 1.,
	}
	tfMessage, err := proto.Marshal(&tm)
	if err != nil {
		zap.S().Errorf("unable to marshal protobuf maxThrottleCtrl message: %v", err)
		return
	}
	publish(a.client, a.maxThrottleCtrlTopic, tfMessage)
}

func (a *Part) publishDriveMode() {
	dm := events.DriveModeMessage{
		DriveMode: a.DriveMode(),
	}
	driveModeMessage, err := proto.Marshal(&dm)
	if err != nil {
		zap.S().Errorf("unable to marshal protobuf driveMode message: %v", err)
		return
	}
	publish(a.client, a.driveModeTopic, driveModeMessage)
}

func (a *Part) publishSwitchRecord() {
	sr := events.SwitchRecordMessage{
		Enabled: !a.SwitchRecord(),
	}
	switchRecordMessage, err := proto.Marshal(&sr)
	if err != nil {
		zap.S().Errorf("unable to marshal protobuf SwitchRecord message: %v", err)
		return
	}
	publish(a.client, a.switchRecordTopic, switchRecordMessage)
}

func (a *Part) convertPwmFeedBackToPercent(value int) float32 {
	return float32(a.throttleFeedbackThresholds.ValueOf(value))
}

var publish = func(client mqtt.Client, topic string, payload []byte) {
	client.Publish(topic, 0, false, payload)
}