package internal

import (
	"encoding/json"
	"log"
	"sync"
	"time"

	"github.com/cenkalti/backoff/v4"
	"github.com/jcollie/go-homeassistant"
	"github.com/jcollie/go-streamdeck"
	"github.com/pkg/errors"
)

// Button .
type Button interface {
	InitializeButton()
	StateChange(entityID string, state string)
	ButtonPressed(sd *streamdeck.StreamDeck, x int, y int, timestamp time.Time)
	ButtonReleased(sd *streamdeck.StreamDeck, x int, y int, timestamp time.Time)
}

// ButtonInfo .
type ButtonInfo struct {
	X int
	Y int
}

var myButtons []Button

type eventWatcher struct {
	sync.Mutex
	id uint64
}

var theEventWatcher eventWatcher

// StartWatchingEvents .
func StartWatchingEvents(ha *homeassistant.Connection) error {
	var err error

	theEventWatcher.Lock()
	defer theEventWatcher.Unlock()

	if theEventWatcher.id != 0 {
		return errors.Errorf("we already seem to be watching events!")
	}

	theEventWatcher.id, err = ha.SubscribeToEvents("state_changed", &theEventWatcher)
	if err != nil {
		return errors.Wrap(err, "unable to subscribe to state changed events")
	}
	log.Printf("subscribe to state changed events command sent")
	return nil
}

func (e *eventWatcher) HandleResult(ha *homeassistant.Connection, subscriptionID uint64, success bool, result json.RawMessage) {
	log.Printf("eventwatcher result: %v %s\n", success, string(result))
}

func (e *eventWatcher) HandleEvent(ha *homeassistant.Connection, subscriptionID uint64, origin string, timeFired time.Time, event *homeassistant.Event) {
	// fmt.Printf("%s %s %s\n", origin, event.Data.NewState.EntityID, event.Data.NewState.State)
	for _, m := range myButtons {
		m.StateChange(event.Data.NewState.EntityID, event.Data.NewState.State)
	}
}

func (e *eventWatcher) HandleClose(ha *homeassistant.Connection, id uint64) {
	log.Printf("home assistant closed")
	time.Sleep(5 * time.Second)
	e.id = 0
	go func() {
		err := backoff.Retry(
			func() error {
				log.Printf("attempting to watch events")
				return StartWatchingEvents(ha)
			},
			backoff.NewExponentialBackOff(),
		)
		if err != nil {
			log.Printf("unable to start watching events: %+v", err)
		}
	}()
}

type initializeState struct {
	id     uint64
	result chan bool
}

// InitializeState .
func InitializeState(ha *homeassistant.Connection) error {
	var err error
	var i initializeState
	i.result = make(chan bool)
	i.id, err = ha.GetStates(&i)
	if err != nil {
		return errors.Wrap(err, "unable to initialize state")
	}
	result := <-i.result
	if !result {
		return errors.Errorf("problem intiaizlizing states")
	}
	return nil
}

// HandleResult .
func (i *initializeState) HandleResult(ha *homeassistant.Connection, id uint64, success bool, result json.RawMessage) {
	if !success {
		i.result <- false
		close(i.result)
		return
	}
	var states []homeassistant.State
	err := json.Unmarshal(result, &states)
	if err != nil {
		log.Printf("unable to unmarshall states: %+v", err)
		return
	}
	for _, state := range states {
		for _, m := range myButtons {
			m.StateChange(state.EntityID, state.State)
		}
	}
	i.result <- true
	close(i.result)
}

func (i *initializeState) HandleClose(ha *homeassistant.Connection, id uint64) {
	log.Printf("home assistant closed")
	time.Sleep(5 * time.Second)
	i.id = 0
	go func() {
		err := backoff.Retry(
			func() error {
				log.Printf("attempting to initialize state")
				return InitializeState(ha)
			},
			backoff.NewExponentialBackOff(),
		)
		if err != nil {
			log.Printf("unable to initalize state: %+v", err)
		}
	}()
}