package hue

import (
	"context"
	"encoding/json"
	"encoding/xml"
	"fmt"
	"git.aiterp.net/lucifer/new-server/internal/lerrors"
	"git.aiterp.net/lucifer/new-server/models"
	"log"
	"net/http"
	"strconv"
	"sync"
	"sync/atomic"
	"time"
)

type Driver struct {
	mu      sync.Mutex
	bridges []*Bridge
}

func (d *Driver) SearchBridge(ctx context.Context, address, _ string, dryRun bool) ([]models.Bridge, error) {
	if address == "" {
		if !dryRun {
			return nil, lerrors.ErrAddressOnlyDryRunnable
		}

		res, err := http.Get("https://discovery.meethue.com")
		if err != nil {
			return nil, err
		}
		defer res.Body.Close()

		entries := make([]DiscoveryEntry, 0, 8)
		err = json.NewDecoder(res.Body).Decode(&entries)
		if err != nil {
			return nil, err
		}

		bridges := make([]models.Bridge, 0, len(entries))
		for _, entry := range entries {
			bridges = append(bridges, models.Bridge{
				ID:      -1,
				Name:    entry.Id,
				Driver:  models.DTHue,
				Address: entry.InternalIPAddress,
				Token:   "",
			})
		}

		return bridges, nil
	}

	deviceInfo := BridgeDeviceInfo{}
	res, err := http.Get(fmt.Sprintf("http://%s/description.xml", address))
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	err = xml.NewDecoder(res.Body).Decode(&deviceInfo)
	if err != nil {
		return nil, err
	}

	bridge := models.Bridge{
		ID:      -1,
		Name:    deviceInfo.Device.FriendlyName,
		Driver:  models.DTHue,
		Address: address,
		Token:   "",
	}

	if !dryRun {
		b := &Bridge{host: address}

		timeout, cancel := context.WithTimeout(ctx, time.Second*30)
		defer cancel()

		ticker := time.NewTicker(time.Second)
		defer ticker.Stop()

		for range ticker.C {
			token, err := b.getToken(timeout)
			if err != nil {
				if err == errLinkButtonNotPressed {
					continue
				}

				return nil, err
			}

			bridge.Token = token
			b.token = token
			break
		}
	}

	return []models.Bridge{bridge}, nil
}

func (d *Driver) SearchDevices(ctx context.Context, bridge models.Bridge, timeout time.Duration) ([]models.Device, error) {
	b, err := d.ensureBridge(ctx, bridge)
	if err != nil {
		return nil, err
	}

	before, err := d.ListDevices(ctx, bridge)
	if err != nil {
		return nil, err
	}

	if timeout.Seconds() < 10 {
		timeout = time.Second * 10
	}
	halfTime := timeout / 2

	err = b.StartDiscovery(ctx, "sensors")
	if err != nil {
		return nil, err
	}
	select {
	case <-time.After(halfTime):
	case <-ctx.Done():
		return nil, ctx.Err()
	}

	err = b.StartDiscovery(ctx, "lights")
	if err != nil {
		return nil, err
	}
	select {
	case <-time.After(halfTime):
	case <-ctx.Done():
		return nil, ctx.Err()
	}

	err = b.Refresh(ctx)
	if err != nil {
		return nil, err
	}

	after, err := d.ListDevices(ctx, bridge)
	if err != nil {
		return nil, err
	}

	intersection := make([]models.Device, 0, 4)
	for _, device := range after {
		found := false
		for _, device2 := range before {
			if device2.InternalID == device.InternalID {
				found = true
				break
			}
		}

		if !found {
			intersection = append(intersection, device)
		}
	}

	return intersection, nil
}

func (d *Driver) ListDevices(ctx context.Context, bridge models.Bridge) ([]models.Device, error) {
	b, err := d.ensureBridge(ctx, bridge)
	if err != nil {
		return nil, err
	}

	devices := make([]models.Device, 0, 8)

	lightMap, err := b.getLights(ctx)
	if err != nil {
		return nil, err
	}
	for _, lightInfo := range lightMap {
		device := models.Device{
			ID:         -1,
			BridgeID:   b.externalID,
			InternalID: lightInfo.Uniqueid,
			Icon:       "lightbulb",
			Name:       lightInfo.Name,
			Capabilities: []models.DeviceCapability{
				models.DCPower,
			},
			ButtonNames: nil,
			DriverProperties: map[string]interface{}{
				"modelId":      lightInfo.Modelid,
				"productName":  lightInfo.Productname,
				"swVersion":    lightInfo.Swversion,
				"hueLightType": lightInfo.Type,
			},
			UserProperties: nil,
			State:          models.DeviceState{},
			Tags:           nil,
		}

		hasDimming := false
		hasCT := false
		hasColor := false

		switch lightInfo.Type {
		case "On/off light":
			// Always take DCPower for granted anyway.
		case "Dimmable light":
			hasDimming = true
		case "Color temperature light":
			hasDimming = true
			hasCT = true
		case "Color light":
			hasDimming = true
			hasColor = true
		case "Extended color light":
			hasDimming = true
			hasColor = true
			hasCT = true
		}

		ctrl := lightInfo.Capabilities.Control
		if hasDimming {
			device.Capabilities = append(device.Capabilities, models.DCIntensity)
		}
		if hasCT {
			device.Capabilities = append(device.Capabilities, models.DCColorKelvin)
			device.DriverProperties["minKelvin"] = 1000000 / ctrl.CT.Max
			device.DriverProperties["maxKelvin"] = 1000000 / ctrl.CT.Min
		}
		if hasColor {
			device.Capabilities = append(device.Capabilities, models.DCColorHS)
			device.DriverProperties["gamutType"] = ctrl.Colorgamuttype
			device.DriverProperties["gamutData"] = ctrl.Colorgamut
		}
		device.DriverProperties["maxLumen"] = strconv.Itoa(ctrl.Maxlumen)

		devices = append(devices, device)
	}

	sensorMap, err := b.getSensors(ctx)
	if err != nil {
		return nil, err
	}
	for _, sensorInfo := range sensorMap {
		device := models.Device{
			ID:           -1,
			BridgeID:     b.externalID,
			InternalID:   sensorInfo.UniqueID,
			Name:         sensorInfo.Name,
			Capabilities: []models.DeviceCapability{},
			ButtonNames:  []string{},
			DriverProperties: map[string]interface{}{
				"modelId":      sensorInfo.Modelid,
				"productName":  sensorInfo.Productname,
				"swVersion":    sensorInfo.Swversion,
				"hueLightType": sensorInfo.Type,
			},
			UserProperties: nil,
			State:          models.DeviceState{},
			Tags:           nil,
		}

		switch sensorInfo.Type {
		case "ZLLSwitch":
			device.Capabilities = append(device.Capabilities, models.DCButtons)
			device.ButtonNames = append(buttonNames[:0:0], buttonNames...)
			device.Icon = "lightswitch"
		case "ZLLPresence":
			device.Capabilities = append(device.Capabilities, models.DCPresence)
			device.Icon = "sensor"
		case "ZLLTemperature":
			device.Capabilities = append(device.Capabilities, models.DCTemperatureSensor)
			device.Icon = "thermometer"
		case "Daylight":
			continue
		}

		devices = append(devices, device)
	}

	return devices, nil
}

func (d *Driver) Publish(ctx context.Context, bridge models.Bridge, devices []models.Device) error {
	b, err := d.ensureBridge(ctx, bridge)
	if err != nil {
		return err
	}

	err = b.Refresh(ctx)
	if err != nil {
		return err
	}

	b.mu.Lock()
	for _, device := range devices {
		for _, state := range b.lightStates {
			if device.InternalID == state.uniqueID {
				state.externalID = device.ID
				state.Update(device.State)
				break
			}
		}

		for _, state := range b.sensorStates {
			if device.InternalID == state.uniqueID {
				state.externalID = device.ID
				break
			}
		}
	}
	b.mu.Unlock()

	atomic.StoreUint32(&b.syncingPublish, 1)
	defer atomic.StoreUint32(&b.syncingPublish, 0)

	return b.SyncStale(ctx)
}

func (d *Driver) Run(ctx context.Context, bridge models.Bridge, ch chan<- models.Event) error {
	b, err := d.ensureBridge(ctx, bridge)
	if err != nil {
		return err
	}

	fastTicker := time.NewTicker(time.Second / 5)
	slowTicker := time.NewTicker(time.Second / 2)
	selectedTicker := fastTicker
	ticksUntilRefresh := 0
	ticksSinceChange := 0

	for {
		select {
		case <-selectedTicker.C:
			if atomic.LoadUint32(&b.syncingPublish) == 1 {
				continue
			}

			if ticksUntilRefresh <= 0 {
				err := b.Refresh(ctx)
				if err != nil {
					return err
				}
				err = b.SyncStale(ctx)
				if err != nil {
					return err
				}

				ticksUntilRefresh = 60
			}

			events, err := b.SyncSensors(ctx)
			if err != nil {
				return err
			}

			for _, event := range events {
				ch <- event
				ticksSinceChange = 0
			}

			if ticksSinceChange > 30 {
				selectedTicker = slowTicker
			} else if ticksSinceChange == 0 {
				selectedTicker = fastTicker
			}
		case <-ctx.Done():
			return ctx.Err()
		}

		ticksUntilRefresh -= 1
		ticksSinceChange += 1
	}
}

func (d *Driver) ForgetDevice(ctx context.Context, bridge models.Bridge, device models.Device) error {
	b, err := d.ensureBridge(ctx, bridge)
	if err != nil {
		return err
	}

	return b.ForgetDevice(ctx, device)
}

func (d *Driver) ensureBridge(ctx context.Context, info models.Bridge) (*Bridge, error) {
	d.mu.Lock()
	for _, bridge := range d.bridges {
		if bridge.host == info.Address {
			d.mu.Unlock()
			return bridge, nil
		}
	}
	d.mu.Unlock()

	bridge := &Bridge{
		host:       info.Address,
		token:      info.Token,
		externalID: info.ID,
	}

	// If this call succeeds, then the token is ok.
	lightMap, err := bridge.getLights(ctx)
	if err != nil {
		return nil, err
	}
	log.Printf("Found %d lights on bridge %d", len(lightMap), bridge.externalID)

	// To avoid a potential duplicate, try looking for it again before inserting
	d.mu.Lock()
	for _, bridge := range d.bridges {
		if bridge.host == info.Address {
			d.mu.Unlock()
			return bridge, nil
		}
	}
	d.bridges = append(d.bridges, bridge)
	d.mu.Unlock()

	return bridge, nil
}