package infinitime

import (
	"bytes"
	"encoding/binary"
	"errors"
	"github.com/muka/go-bluetooth/bluez/profile/gatt"
)

const (
	NavFlagsChar    = "00010001-78fc-48fe-8e23-433b3a1942d0"
	NavNarrativeChar= "00010002-78fc-48fe-8e23-433b3a1942d0"
	NavManDistChar  = "00010003-78fc-48fe-8e23-433b3a1942d0"
	NavProgressChar = "00010004-78fc-48fe-8e23-433b3a1942d0"
)

type NavigationCtrl struct {
	flagsChar    *gatt.GattCharacteristic1
	narrativeChar*gatt.GattCharacteristic1
	mandistChar  *gatt.GattCharacteristic1
	progressChar *gatt.GattCharacteristic1
}

type NavigationEvent struct {
	flag         string
	narrative    string
	dist         string
	progress     uint8
}

var (
	ErrNavProgress      = errors.New("progress needs to between 0 and 100")
	ErrNavInvalidFlag   = errors.New("this flag is invalid")
)

var NavFlagNames = []string{
	"arrive", "arrive-left", "arrive-right", "arrive-straight",
	"close",
	"continue", "continue-left", "continue-right", "continue-slight-left",
	"continue-slight-right", "continue-straight", "continue-uturn",
	"depart", "depart-left", "depart-right", "depart-straight",
	"end-of-road-left", "end-of-road-right",
	"ferry", "flag",
	"fork", "fork-left", "fork-right", "fork-straight",
	"fork-slight-left", "fork-slight-right",
	"invalid", "invalid-left", "invalid-right",
	"invalid-slight-left", "invalid-slight-right",
	"invalid-straight", "invalid-uturn",
	"merge-left", "merge-right", "merge-slight-left",
	"merge-slight-right", "merge-straight",
	"new-name-left", "new-name-right", "new-name-sharp-left", "new-name-sharp-right",
	"new-name-slight-left", "new-name-slight-right", "new-name-straight",
	"notification-left", "notification-right",
	"notification-sharp-left", "notification-sharp-right",
	"notification-slight-left", "notification-slight-right",
	"notification-straight",
	"off-ramp-left", "off-ramp-right", "off-ramp-sharp-left", "off-ramp-sharp-right",
	"off-ramp-slight-left", "off-ramp-slight-right", "off-ramp-straight",
	"on-ramp-left", "on-ramp-right", "on-ramp-sharp-left", "on-ramp-sharp-right",
	"on-ramp-slight-left", "on-ramp-slight-right", "on-ramp-straight",
	"rotary", "rotary-left", "rotary-right", "rotary-sharp-left", "rotary-sharp-right",
	"rotary-slight-left", "rotary-slight-right", "rotary-straight",
	"roundabout", "roundabout-left", "roundabout-right",
	"roundabout-sharp-left", "roundabout-sharp-right",
	"roundabout-slight-left", "roundabout-slight-right", "roundabout-straight",
	"turn-left", "turn-right", "turn-sharp-left", "turn-sharp-right",
	"turn-slight-left", "turn-slight-right", "turn-stright",
	"updown", "uturn",
}

func CheckValidNavFlag(flag string) error {
	for _, v := range NavFlagNames {
		if v == flag {
			return nil
		}
	}
	return ErrNavInvalidFlag
}

// Navigation sends a NavigationEvent to the watch
func (i *Device) SetNavigation(flag string, narrative string, dist string, progress uint8) error {
	if progress > 100 {
		return ErrNavProgress
	}
	if err := CheckValidNavFlag(flag); err != nil {
		return err
	}

	if flag != i.navigationEv.flag {
		log.Debug().Str("func", "Navigation").
		    Msg("Sending flag")
		if err := i.checkStatus(i.Navigation.flagsChar, NavFlagsChar); err != nil {
			return err
		}
		if err := i.Navigation.flagsChar.WriteValue([]byte(flag), nil); err != nil {
			return err
		}
		i.navigationEv.flag = flag
	}

	if narrative != i.navigationEv.narrative {
		log.Debug().Str("func", "Navigation").
		    Msg("Sending narrative")
		if err := i.checkStatus(i.Navigation.narrativeChar, NavNarrativeChar); err != nil {
			return err
		}
		if err := i.Navigation.narrativeChar.WriteValue([]byte(narrative), nil); err != nil {
			return err
		}
		i.navigationEv.narrative = narrative
	}

	if dist != i.navigationEv.dist {
		log.Debug().Str("func", "Navigation").
		    Msg("Sending mandist")
		if err := i.checkStatus(i.Navigation.mandistChar, NavManDistChar); err != nil {
			return err
		}
		if err := i.Navigation.mandistChar.WriteValue([]byte(dist), nil); err != nil {
			return err
		}
		i.navigationEv.dist = dist
	}

	if progress != i.navigationEv.progress {
		log.Debug().Str("func", "Navigation").
		    Msg("Sending progress")
		if err := i.checkStatus(i.Navigation.progressChar, NavProgressChar); err != nil {
			return err
		}
		buf := &bytes.Buffer{}
		binary.Write(buf, binary.LittleEndian, progress)
		if err := i.Navigation.progressChar.WriteValue(buf.Bytes(), nil); err != nil {
			return err
		}
		i.navigationEv.progress = progress
	}

	return nil
}