package pages

import (
	"context"
	"fmt"
	"math"
	"sync"
	"time"

	"gitea.unprism.ru/KRBL/mpu/mpu"
	"gitea.unprism.ru/KRBL/sim-modem/api/modem/gps"
	"gitea.unprism.ru/yotia/display-test/components"
	"gitea.unprism.ru/yotia/display-test/drawer"
)

// Debug variant:
// line0 - time
// time1 - tempreture, speed
// time2 - latitude
// time3 - longitude

const (
	timeLayout = "01.09.06 15:04:05"
)

// Some layout constants

type statusPage struct {
	drawer drawer.Drawer // Drawer with dysplay

	// Status data
	st systemStatus

	timeShift time.Duration

	// Visual components
	line0 components.Text
	line1 components.Text
	line2 components.Text
	line3 components.Text
	// Layout values
	signalX  int
	serviceX int

	// Threads sync
	ctx    context.Context
	cancel context.CancelFunc
	wg     sync.WaitGroup
}

// Only functions that control content of page
type StatusPageContent interface {
	SystemStatusSetter
	SetTimeShift(shift time.Duration)
}

type StatusPage interface {
	Page
	StatusPageContent
}

func NewStatusPage(d drawer.Drawer) (StatusPage, error) {
	// Check display
	if err := d.GetDisplay().IsReady(); err != nil {
		return nil, fmt.Errorf("display is ready: %w", err)
	}

	// Create visual components
	line0, err := components.NewText(d, 0, drawer.LineH*0)
	if err != nil {
		return nil, fmt.Errorf("create line0: %w", err)
	}
	line1, err := components.NewText(d, 0, drawer.LineH*1)
	if err != nil {
		return nil, fmt.Errorf("create line1: %w", err)
	}
	line2, err := components.NewText(d, 0, drawer.LineH*2)
	if err != nil {
		return nil, fmt.Errorf("create line2: %w", err)
	}
	line3, err := components.NewText(d, 0, drawer.LineH*3)
	if err != nil {
		return nil, fmt.Errorf("create line3: %w", err)
	}

	// Calculate signal and service glyphs' pos
	signalX := d.W() - drawer.CommonGlyphs[drawer.SignalStatusGlyphI].W - drawer.CommonGlyphs[drawer.ServiceStatusGlyphI].W - drawer.CharGap
	serviceX := d.W() - drawer.CommonGlyphs[drawer.ServiceStatusGlyphI].W

	return &statusPage{
		drawer: d,

		line0: line0,
		line1: line1,
		line2: line2,
		line3: line3,

		signalX:  signalX,
		serviceX: serviceX,
	}, nil
}

func (p *statusPage) Activate() {
	// Draw
	p.drawer.Clear()
	//p.line0.SetStr("DEBUG line0")
	//p.line1.SetStr("DEBUG line1")
	//p.line2.SetStr("DEBUG line2")
	//p.line3.SetStr("DEBUG line3")
	p.line0.Draw()
	p.line1.Draw()
	p.line2.Draw()
	p.line3.Draw()

	// At the right-top corner there are signal then service status glyphs
	// Layout:
	//   gap | signal | gap | service
	p.SetRssi(0)

	// Setup threads
	p.ctx, p.cancel = context.WithCancel(context.Background())
	go p.timeUpdateLoop()
}

func (p *statusPage) Diactivate() {
	// Stop all support threads
	p.cancel()
	p.wg.Wait()
}

func (p *statusPage) SetTimeShift(shift time.Duration) {
	p.st.mutex.Lock()
	defer p.st.mutex.Unlock()

	p.timeShift = shift
}

func (p *statusPage) SetGps(newData gps.Data) {
	p.st.mutex.Lock()
	defer p.st.mutex.Unlock()

	p.st.gpsData = newData

	// Format and update coords

	// Langitude, longitude store format: ddmm.mmmmmm, dddmm.mmmmmm
	// Latitude and longitude output format:
	//  DD° MM.MMM' N
	// DDD° MM.MMM' W
	latStr := fmt.Sprintf("   %02d°%06.3f' %s", int(p.st.gpsData.Latitude)/100, math.Mod(p.st.gpsData.Latitude, 100), p.st.gpsData.LatitudeIndicator)
	p.line2.SetStr(latStr)
	logStr := fmt.Sprintf("  %03d°%06.3f' %s", int(p.st.gpsData.Longitude)/100, math.Mod(p.st.gpsData.Longitude, 100), p.st.gpsData.LongitudeIndicator)
	p.line3.SetStr(logStr)
}

func (p *statusPage) SetMpu(newData mpu.Data) {
	p.st.mutex.Lock()
	defer p.st.mutex.Unlock()

	p.st.mpuData = newData
}

// Only safely updates local values
func (p *statusPage) setRssi(newData int) {
	p.st.mutex.Lock()
	defer p.st.mutex.Unlock()

	p.st.rssi = newData
}

func (p *statusPage) setService(svc string) {
	p.st.mutex.Lock()
	defer p.st.mutex.Unlock()

	p.st.service = svc
}

func getSignalStrength(rssi int) int {
	// Signal strength clasification (from google):
	// 0 - no signal        -110 to ...
	// 1 - poor signal       -90 to -110
	// 2 - fair signal       -70 to -90
	// 3 - good signal       -50 to -70
	// 4 - excelent signal   ... to -50

	// Description from "sim-modem/api/modem/utils/signal.go"
	// 0          -113 dBm or less
	// 1          -111 dBm
	// 2...30     -109... -53 dBm
	// 31         -51 dBm or greater
	// 99         not known or not detectable
	// 100        -116 dBm or less
	// 101        -115 dBm
	// 102…191    -114... -26dBm
	// 191        -25 dBm or greater
	// 199        not known or not detectable
	// 100…199    expand to TDSCDMA, indicate RSCPreceived

	// Cut certain cases
	switch rssi {
	case 99, 199: // not known or not detectable
		return 0
	case 0, 1, 100, 101: // no signal
		return 0
	case 31, 191: // Excelent
		return 4
	}

	// Ranged values
	if rssi >= 2 && rssi <= 30 {
		// it is in -109...-53 dBm
		// Simplified interpolation from 2..30 to -109...-53 and then to 0...4
		return int((float64(rssi)*2-3)/20) + 1
	}
	if rssi >= 102 && rssi <= 191 {
		// it is in -114...-26 dBm
		// Simplified interpolation from 2..30 to -114...-26 and then to 0...4
		return min(int((float64(rssi-102)+15)/20), 4)
	}

	return 0 // Invalid value
}

func getServiceStrength(service string) int {
	// Service clasification by speed:
	// 0 - no service - "NO SERVICE"
	// 1 - 1G - do not use
	// 2 - 2G - "GSM"
	// 3 - 3G - "WCDMA"
	// 4 - 4G - "LTE", "TDS"

	switch service {
	case "NO SERVICE":
		return 0
	case "GSM":
		return 2
	case "WCDMA":
		return 3
	case "LTE", "TDS":
		return 4
	}

	return 0 // Invalid value
}

func (p *statusPage) SetRssi(rssi int) {
	p.setRssi(rssi) // Save data (with short lock)

	// Update screen image
	ss := getSignalStrength(rssi) // Signal strength in [0; 4] range
	p.drawer.CopyImg(p.signalX, 0, drawer.CommonGlyphs[drawer.SignalStatusGlyphI+ss])
	p.drawer.GetDisplay().FlushByMask(p.drawer.GetDisplay().GetFlushMaskBit(1, 0))
}

func (p *statusPage) SetService(svc string) {
	p.setService(svc) // Save data (with short lock)

	// Update screen image
	ss := getServiceStrength(svc) // Service strength in [0; 4] range
	p.drawer.CopyImg(p.serviceX, 0, drawer.CommonGlyphs[drawer.ServiceStatusGlyphI+ss])
	p.drawer.GetDisplay().FlushByMask(p.drawer.GetDisplay().GetFlushMaskBit(1, 0))
}

func (p *statusPage) timeUpdateLoop() {
	p.wg.Add(1)

	// Because ticker do not send signal immediately
	p.line0.SetStr(time.Now().Add(p.timeShift).Format(timeLayout))

	ticker := time.NewTicker(time.Second)
	for {
		select {
		case <-p.ctx.Done():
			ticker.Stop()
			p.wg.Done()
			return
		case now := <-ticker.C:
			p.line0.SetStr(now.Add(p.timeShift).Format(timeLayout))
		}
	}
}

func (p *statusPage) Close() (outErr error) {

	// TODO Not the best way...
	if err := p.line0.Close(); err != nil {
		outErr = fmt.Errorf("line 0 close: %w:", err)
	}
	if err := p.line1.Close(); err != nil {
		outErr = fmt.Errorf("line 1 close: %w:", err)
	}
	if err := p.line2.Close(); err != nil {
		outErr = fmt.Errorf("line 2 close: %w:", err)
	}
	if err := p.line3.Close(); err != nil {
		outErr = fmt.Errorf("line 3 close: %w:", err)
	}
	return
}