package models

import (
	"context"
	"strings"
	"time"
)

type Device struct {
	ID               int                     `json:"id"`
	BridgeID         int                     `json:"bridgeID"`
	InternalID       string                  `json:"internalId"`
	Icon             string                  `json:"icon"`
	Name             string                  `json:"name"`
	Capabilities     []DeviceCapability      `json:"capabilities"`
	ButtonNames      []string                `json:"buttonNames"`
	DriverProperties map[string]interface{}  `json:"driverProperties"`
	UserProperties   map[string]string       `json:"userProperties"`
	SceneAssignments []DeviceSceneAssignment `json:"sceneAssignments"`
	State            DeviceState             `json:"state"`
	Tags             []string                `json:"tags"`
}

type DeviceUpdate struct {
	Icon           *string            `json:"icon"`
	Name           *string            `json:"name"`
	UserProperties map[string]*string `json:"userProperties"`
}

// DeviceState contains optional state values that
//  - Power: Whether the device is powered on
//  - Color: Color value, if a color setting can be set on the device
//  - Intensity: e.g. brightness, range 0..=1
//  - Temperature: e.g. for thermostats
type DeviceState struct {
	Power       bool       `json:"power"`
	Color       ColorValue `json:"color,omitempty"`
	Intensity   float64    `json:"intensity,omitempty"`
	Temperature float64    `json:"temperature"`
}

type DeviceScene struct {
	SceneID    int       `json:"sceneId"`
	Time       time.Time `json:"time"`
	DurationMS int64     `json:"duration"`
	Tag        string    `json:"tag"`
}

type NewDeviceState struct {
	Power       *bool    `json:"power"`
	Color       *string  `json:"color"`
	Intensity   *float64 `json:"intensity"`
	Temperature *int     `json:"temperature"`
}

type DeviceCapability string

type SaveMode int

const (
	SMState      SaveMode = 1
	SMProperties SaveMode = 2
	SMTags       SaveMode = 4
)

type DeviceRepository interface {
	Find(ctx context.Context, id int) (*Device, error)
	FetchByReference(ctx context.Context, kind ReferenceKind, value string) ([]Device, error)
	Save(ctx context.Context, device *Device, mode SaveMode) error
	SaveMany(ctx context.Context, mode SaveMode, devices []Device) error
	Delete(ctx context.Context, device *Device) error
}

func DeviceCapabilitiesToStrings(caps []DeviceCapability) []string {
	res := make([]string, 0, len(caps))
	for _, cap := range caps {
		res = append(res, string(cap))
	}

	return res
}

var (
	DCPower              DeviceCapability = "Power"
	DCColorHS            DeviceCapability = "ColorHS"
	DCColorHSK           DeviceCapability = "ColorHSK"
	DCColorKelvin        DeviceCapability = "ColorKelvin"
	DCButtons            DeviceCapability = "Buttons"
	DCPresence           DeviceCapability = "Presence"
	DCIntensity          DeviceCapability = "Intensity"
	DCTemperatureControl DeviceCapability = "TemperatureControl"
	DCTemperatureSensor  DeviceCapability = "TemperatureSensor"
)

var Capabilities = []DeviceCapability{
	DCPower,
	DCColorHS,
	DCColorKelvin,
	DCButtons,
	DCPresence,
	DCIntensity,
	DCTemperatureControl,
	DCTemperatureSensor,
}

func (d *Device) ApplyUpdate(update DeviceUpdate) {
	if update.Name != nil {
		d.Name = *update.Name
	}
	if update.Icon != nil {
		d.Icon = *update.Icon
	}
	if d.UserProperties == nil {
		d.UserProperties = make(map[string]string)
	}
	for key, value := range update.UserProperties {
		if value != nil {
			d.UserProperties[key] = *value
		} else {
			delete(d.UserProperties, key)
		}
	}
}

func (d *Device) Validate() error {
	d.Name = strings.Trim(d.Name, " \t\n ")
	if d.Name == "" {
		return ErrInvalidName
	}

	newCaps := make([]DeviceCapability, 0, len(d.Capabilities))
	for _, currCap := range d.Capabilities {
		for _, validCap := range Capabilities {
			if currCap == validCap {
				newCaps = append(newCaps, currCap)
				break
			}
		}
	}
	d.Capabilities = newCaps

	return nil
}

func (d *Device) HasTag(tags ...string) bool {
	for _, c := range d.Tags {
		for _, c2 := range tags {
			if c == c2 {
				return true
			}
		}
	}

	return false
}

func (d *Device) HasCapability(capabilities ...DeviceCapability) bool {
	for _, c := range d.Capabilities {
		for _, c2 := range capabilities {
			if c == c2 {
				return true
			}
		}
	}

	return false
}

func (d *Device) SetState(newState NewDeviceState) error {
	if newState.Power != nil && d.HasCapability(DCPower) {
		d.State.Power = *newState.Power
	}

	if newState.Color != nil {
		parsed, err := ParseColorValue(*newState.Color)
		if err != nil {
			return err
		}

		if (parsed.IsKelvin() && d.HasCapability(DCColorKelvin, DCColorHSK)) || (parsed.IsHueSat() && d.HasCapability(DCColorHS)) {
			d.State.Color = parsed
		}
	}

	if newState.Intensity != nil && d.HasCapability(DCIntensity) {
		d.State.Intensity = *newState.Intensity
	}

	return nil
}

func (s *NewDeviceState) Interpolate(other NewDeviceState, fac float64) NewDeviceState {
	n := NewDeviceState{}

	if s.Power != nil && other.Power != nil {
		if fac >= 0.5 {
			n.Power = other.Power
		} else {
			n.Power = s.Power
		}
	}

	if s.Color != nil && other.Color != nil {
		sc, err := ParseColorValue(*s.Color)
		oc, err2 := ParseColorValue(*other.Color)
		if err == nil && err2 == nil {
			rc := ColorValue{}
			rc.Hue = interpolateFloat(sc.Hue, oc.Hue, fac)
			rc.Saturation = interpolateFloat(sc.Saturation, oc.Saturation, fac)
			rc.Kelvin = interpolateInt(sc.Kelvin, oc.Kelvin, fac)

			rcStr := rc.String()
			n.Color = &rcStr
		}
	}

	if s.Intensity != nil && other.Intensity != nil {
		n.Intensity = new(float64)
		*n.Intensity = interpolateFloat(*s.Intensity, *other.Intensity, fac)
	}

	return n
}

func interpolateFloat(a, b, fac float64) float64 {
	return (a * (1 - fac)) + (b * fac)
}

func interpolateInt(a, b int, fac float64) int {
	return int((float64(a) * (1 - fac)) + (float64(b) * fac))
}