package devices

import (
	"context"
	"xiaomihome/xiaomi"
)

// Thermostat 温控器统一控制接口
type Thermostat interface {
	Device
	TurnOn(ctx context.Context) error
	TurnOff(ctx context.Context) error
	IsOn(ctx context.Context) (bool, error)
	SetTargetTemp(ctx context.Context, temp float64) error
	GetTargetTemp(ctx context.Context) (float64, error)
	GetCurrentTemp(ctx context.Context) (float64, error)
	SetHeating(ctx context.Context, on bool) error
	IsHeating(ctx context.Context) (bool, error)

	OnStateChanged(handler func(state HeaterState, changed string)) (string, error)
}

type thermostatDevice struct {
	BaseDevice
	propOn          siidPiid
	propTargetTemp  siidPiid
	propCurrentTemp siidPiid
	propHeating     siidPiid
	stateCache      HeaterState
}

func NewThermostat(client *xiaomi.Client, info *xiaomi.DeviceInfo) (Thermostat, error) {
	d := &thermostatDevice{BaseDevice: NewBaseDevice(client, info)}
	resolver := d.getSpecResolver()
	if resolver == nil { return nil, xiaomi.ErrNoSPEC }
	siid, piid, ok := resolver.find("on")
	if !ok { return nil, xiaomi.ErrNotSupported }
	d.propOn = siidPiid{siid, piid, true}
	if s, p, ok := resolver.find("target-temperature"); ok { d.propTargetTemp = siidPiid{s, p, true} }
	if s, p, ok := resolver.find("temperature"); ok { d.propCurrentTemp = siidPiid{s, p, true} }
	if s, p, ok := resolver.find("heater"); ok { d.propHeating = siidPiid{s, p, true} }
	return d, nil
}

func (d *thermostatDevice) TurnOn(ctx context.Context) error {
	if !d.propOn.valid { return xiaomi.ErrNotSupported }
	return d.SetProp(ctx, d.propOn.siid, d.propOn.piid, true)
}
func (d *thermostatDevice) TurnOff(ctx context.Context) error {
	if !d.propOn.valid { return xiaomi.ErrNotSupported }
	return d.SetProp(ctx, d.propOn.siid, d.propOn.piid, false)
}
func (d *thermostatDevice) IsOn(ctx context.Context) (bool, error) {
	if !d.propOn.valid { return false, xiaomi.ErrNotSupported }
	prop, err := d.GetProp(ctx, d.propOn.siid, d.propOn.piid)
	if err != nil { return false, err }
	if b, ok := prop.Value.(bool); ok { return b, nil }
	return false, nil
}
func (d *thermostatDevice) SetTargetTemp(ctx context.Context, temp float64) error {
	if !d.propTargetTemp.valid { return xiaomi.ErrNotSupported }
	return d.SetProp(ctx, d.propTargetTemp.siid, d.propTargetTemp.piid, temp)
}
func (d *thermostatDevice) GetTargetTemp(ctx context.Context) (float64, error) {
	if !d.propTargetTemp.valid { return 0, xiaomi.ErrNotSupported }
	prop, err := d.GetProp(ctx, d.propTargetTemp.siid, d.propTargetTemp.piid)
	if err != nil { return 0, err }
	return toFloat(prop.Value), nil
}
func (d *thermostatDevice) GetCurrentTemp(ctx context.Context) (float64, error) {
	if !d.propCurrentTemp.valid { return 0, xiaomi.ErrNotSupported }
	prop, err := d.GetProp(ctx, d.propCurrentTemp.siid, d.propCurrentTemp.piid)
	if err != nil { return 0, err }
	return toFloat(prop.Value), nil
}
func (d *thermostatDevice) SetHeating(ctx context.Context, on bool) error {
	if !d.propHeating.valid { return xiaomi.ErrNotSupported }
	return d.SetProp(ctx, d.propHeating.siid, d.propHeating.piid, on)
}
func (d *thermostatDevice) IsHeating(ctx context.Context) (bool, error) {
	if !d.propHeating.valid { return false, xiaomi.ErrNotSupported }
	prop, err := d.GetProp(ctx, d.propHeating.siid, d.propHeating.piid)
	if err != nil { return false, err }
	if b, ok := prop.Value.(bool); ok { return b, nil }
	return false, nil
}

func (d *thermostatDevice) OnStateChanged(handler func(state HeaterState, changed string)) (string, error) {
	type field struct{ siid, piid int; name string; fill func(*HeaterState, interface{}) }
	var fields []field
	if d.propOn.valid {
		fields = append(fields, field{d.propOn.siid, d.propOn.piid, "on", func(s *HeaterState, v interface{}) { s.On, _ = v.(bool) }})
	}
	if d.propTargetTemp.valid {
		fields = append(fields, field{d.propTargetTemp.siid, d.propTargetTemp.piid, "target-temperature", func(s *HeaterState, v interface{}) { s.TargetTemp = toFloat(v) }})
	}
	if d.propCurrentTemp.valid {
		fields = append(fields, field{d.propCurrentTemp.siid, d.propCurrentTemp.piid, "temperature", func(s *HeaterState, v interface{}) { s.CurrentTemp = toFloat(v) }})
	}
	if len(fields) == 0 { return "", xiaomi.ErrNotSupported }
	return d.SubProp(0, 0, func(did string, prop *xiaomi.PropertyValue) {
		for _, f := range fields {
			if f.siid == prop.SIID && f.piid == prop.PIID {
				f.fill(&d.stateCache, prop.Value)
				handler(d.stateCache, f.name)
				return
			}
		}
	})
}