package core

import (
	"encoding/json"
	"errors"
	"fmt"
	"log"
	"sync"
	"time"
)

// TODO: adapt HNR-INS data to continue orientation stream

type Processor interface {
	Process(data *Sensordata) error
}

type pipeline struct {
	syn           synchronizer
	agr           aggregator
	pub           Publisher
	publishTicker *time.Ticker
}

func NewPipeline(d Publisher, publishIntervalMs int, delayUpdateIntervalMs int) *pipeline {
	return &pipeline{
		synchronizer{
			//bufferSize:   100,
			mutex:        &sync.Mutex{},
			updateTicker: time.NewTicker(time.Duration(delayUpdateIntervalMs) * time.Millisecond),
		},
		aggregator{
			tcpMutex:    &sync.Mutex{},
			serialMutex: &sync.Mutex{},
		},
		d,
		time.NewTicker(time.Duration(publishIntervalMs) * time.Millisecond),
	}
}

func (p *pipeline) Run() {
	go p.scheduleSynchronizer()
	go func() {
		for {
			<-p.publishTicker.C
			err := p.Publish()
			if err != nil && err.Error() != "no data available" {
				log.Println(err)
			}
		}
	}()
	log.Println("pipeline: processing service started")
}

func (p *pipeline) Publish() error {
	p.agr.tcpMutex.Lock()
	p.agr.serialMutex.Lock()
	//log.Println(pub.tcpSensorData)
	//log.Println(pub.serialSensorData)
	if (p.agr.tcpSensorData == Sensordata{} && p.agr.serialSensorData == Sensordata{}) {
		p.agr.tcpMutex.Unlock()
		p.agr.serialMutex.Unlock()
		return errors.New("no data available")
	}
	data := map[string]Sensordata{
		string(SOURCE_TCP):    p.agr.tcpSensorData,
		string(SOURCE_SERIAL): p.agr.serialSensorData,
	}
	//p.agr.tcpSensorData = Sensordata{}
	//p.agr.serialSensorData = Sensordata{}
	p.agr.tcpMutex.Unlock()
	p.agr.serialMutex.Unlock()

	jdata, err := json.Marshal(data)
	//log.Println(string(pretty.Pretty(jdata)))
	if err != nil {
		return err
	}
	p.pub.Publish(string(jdata))
	return nil
}

type aggregator struct {
	tcpSensorData    Sensordata
	serialSensorData Sensordata
	tcpMutex         *sync.Mutex
	serialMutex      *sync.Mutex
}

type UnixNanoTime int64

type synchronizer struct {
	tcpSerialDelayMs    int64
	//tcpBuffer     	map[UnixNanoTime]Sensordata
	//serialBuffer  	map[UnixNanoTime]Sensordata
	//bufferSize    	int
	mutex         		*sync.Mutex
	updateTicker  		*time.Ticker
	// should run concurrently
	//
	// Methods:
	// pushSensordata(Sensordata), remove oldest if larger than bufferSize
	// refreshDelay()
	// Schedule()
}

func (p *pipeline) scheduleSynchronizer() {
	log.Println("synchronizer: started")
	for {
		<-p.syn.updateTicker.C
		err := p.refreshDelay()
		if err != nil {
			log.Println(err)
		}
	}
}

func (p *pipeline) refreshDelay() error {
	log.Println("refreshing delay....")
	fmt.Println("Delay TCP/SERIAL", p.syn.tcpSerialDelayMs)
	p.agr.serialMutex.Lock()
	p.agr.tcpMutex.Lock()
	tcpTime := time.Unix(0, p.agr.tcpSensorData.Timestamp)
	serTime := time.Unix(0, p.agr.serialSensorData.Timestamp)
	p.agr.serialMutex.Unlock()
	p.agr.tcpMutex.Unlock()
	if tcpTime.UnixNano() == 0 || serTime.UnixNano() == 0 {
		return errors.New("no sync possible. no data to compare")
	}
	log.Println("TCP", tcpTime.String())
	log.Println("SER", serTime.String())
	log.Println("Difference", tcpTime.Sub(serTime).Milliseconds())
	delay := tcpTime.Sub(serTime).Milliseconds()
	p.syn.tcpSerialDelayMs += delay
	return nil
}

func (p *pipeline) Process(data *Sensordata) error {
	if data == nil {
		return errors.New("nil processing not allowed")
	}
	//log.Println(string(data.SourceId))
	switch data.SourceId {
	case SOURCE_TCP:
		go p.pushTcpDataToBuffer(*data)
	case SOURCE_SERIAL:
		go p.pushSerialDataToBuffer(*data)
	default:
		return errors.New("invalid data source")
	}
	return nil
}

func (p *pipeline) pushTcpDataToBuffer(data Sensordata) {
	if p.syn.tcpSerialDelayMs > 0 {
		time.Sleep(time.Duration(p.syn.tcpSerialDelayMs) * time.Millisecond)
	}
	p.agr.tcpMutex.Lock()
	p.agr.tcpSensorData = p.agr.tcpSensorData.Consolidate2(data)
	p.agr.tcpMutex.Unlock()
}
func (p *pipeline) pushSerialDataToBuffer(data Sensordata) {
	if p.syn.tcpSerialDelayMs < 0 {
		time.Sleep(time.Duration(-p.syn.tcpSerialDelayMs) * time.Millisecond)
	}
	p.agr.serialMutex.Lock()
	p.agr.serialSensorData = p.agr.serialSensorData.Consolidate2(data)
	p.agr.serialMutex.Unlock()
}