package devices

import (
	"context"
	"xiaomihome/xiaomi"
)

// Cover 窗帘/晾衣架统一控制接口
type Cover interface {
	Device
	Open(ctx context.Context) error
	Close(ctx context.Context) error
	Stop(ctx context.Context) error

	SetPosition(ctx context.Context, pct int) error
	GetPosition(ctx context.Context) (int, error)

	OnPropsChanged(handler func(position int)) (string, error)
	GetProps() int
	FetchProps(ctx context.Context) (int, error)
}

type coverDevice struct {
	BaseDevice
	propMotor    siidPiid
	propPosition siidPiid

	propsCache int
}

const (
	coverMotorOpen  = 1
	coverMotorClose = 0
	coverMotorStop  = 2
)

func NewCover(client *xiaomi.Client, info *xiaomi.DeviceInfo) (Cover, error) {
	d := &coverDevice{BaseDevice: NewBaseDevice(client, info)}
	resolver := d.getSpecResolver()
	if resolver == nil {
		return nil, xiaomi.ErrNoSPEC
	}
	siid, piid, ok := resolver.find("motor-control")
	if !ok {
		return nil, xiaomi.ErrNotSupported
	}
	d.propMotor = siidPiid{siid, piid, true}
	if s, p, ok := resolver.find("current-position"); ok {
		d.propPosition = siidPiid{s, p, true}
	}
	return d, nil
}

func (d *coverDevice) Open(ctx context.Context) error {
	if !d.propMotor.valid { return xiaomi.ErrNotSupported }
	return d.SetProp(ctx, d.propMotor.siid, d.propMotor.piid, coverMotorOpen)
}
func (d *coverDevice) Close(ctx context.Context) error {
	if !d.propMotor.valid { return xiaomi.ErrNotSupported }
	return d.SetProp(ctx, d.propMotor.siid, d.propMotor.piid, coverMotorClose)
}
func (d *coverDevice) Stop(ctx context.Context) error {
	if !d.propMotor.valid { return xiaomi.ErrNotSupported }
	return d.SetProp(ctx, d.propMotor.siid, d.propMotor.piid, coverMotorStop)
}
func (d *coverDevice) SetPosition(ctx context.Context, pct int) error {
	if !d.propPosition.valid { return xiaomi.ErrNotSupported }
	return d.SetProp(ctx, d.propPosition.siid, d.propPosition.piid, pct)
}
func (d *coverDevice) GetPosition(ctx context.Context) (int, error) {
	if !d.propPosition.valid { return 0, xiaomi.ErrNotSupported }
	prop, err := d.GetProp(ctx, d.propPosition.siid, d.propPosition.piid)
	if err != nil { return 0, err }
	return toInt(prop.Value), nil
}

func (d *coverDevice) OnPropsChanged(handler func(position int)) (string, error) {
	if !d.propPosition.valid { return "", xiaomi.ErrNotSupported }
	return d.SubProp(0, 0, func(did string, prop *xiaomi.PropertyValue) {
		if prop.SIID == d.propPosition.siid && prop.PIID == d.propPosition.piid {
			d.propsCache = toInt(prop.Value)
			handler(d.propsCache)
		}
	})
}

func (d *coverDevice) GetProps() int { return d.propsCache }
func (d *coverDevice) FetchProps(ctx context.Context) (int, error) {
	pos, err := d.GetPosition(ctx)
	if err != nil { return d.propsCache, err }
	d.propsCache = pos
	return pos, nil
}