package devices

import (
	"context"

	"git.zeroonesoft.cn/golib/xiaomihome/miot"
	"git.zeroonesoft.cn/golib/xiaomihome/xiaomi"
)

// Fan 风扇/新风机统一控制接口。
// 风扇和新风都有 mode 和 fan-level，但部分新风机没有 fan-level，此时用 mode 控制。
type Fan interface {
	Device
	TurnOn(ctx context.Context) error
	TurnOff(ctx context.Context) error
	IsOn(ctx context.Context) (bool, error)

	// 风速控制（有 fan-level 时可用）
	HasFanLevel() bool
	FanLevelValues() []int
	SetFanLevel(ctx context.Context, level int) error
	GetFanLevel(ctx context.Context) (int, error)

	// 模式控制（有 mode+ValueList 时可用，返回原始 uint8 值）
	HasMode() bool
	ModeValues() []int
	SetMode(ctx context.Context, mode int) error
	GetMode(ctx context.Context) (int, error)

	SetOscillation(ctx context.Context, on bool) error
	IsOscillating(ctx context.Context) (bool, error)

	SetNaturalWind(ctx context.Context, on bool) error
	IsNaturalWind(ctx context.Context) (bool, error)

	OnPropsChanged(handler func(props FanProps, changed string)) (string, error)
	GetProps() FanProps
	FetchProps(ctx context.Context) (FanProps, error)
}

// FanProps 风扇/新风机完整状态（MQTT 缓存）
type FanProps struct {
	On          bool `json:"on"`
	FanLevel    int  `json:"fanLevel"`
	Mode        int  `json:"mode"`
	Oscillation bool `json:"oscillation"`
	NaturalWind bool `json:"naturalWind"`
}

type fanDevice struct {
	BaseDevice
	propOn          siidPiid // "on"
	propFanLevel    siidPiid // "fan-level"
	propMode        siidPiid // "mode" — 有 ValueList 时为模式选择器
	propNaturalWind siidPiid // "mode" — 无 ValueList 时为自然风开关
	propOscillation siidPiid // "horizontal-swing" or "oscillation"

	modeValues     []int // 可用模式值列表（来自 SPEC value-list）
	fanLevelValues []int // 可用风速档位值列表

	propsCache FanProps
}

// NewFan creates a Fan control for the given device.
func NewFan(client *xiaomi.Client, info *xiaomi.DeviceInfo) (Fan, error) {
	d := &fanDevice{
		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("fan-level"); ok {
		d.propFanLevel = siidPiid{s, p, true}
		if prop := resolver.prop("fan-level"); prop != nil {
			if len(prop.ValueList) > 0 {
				for _, item := range prop.ValueList {
					d.fanLevelValues = append(d.fanLevelValues, toInt(item.Value))
				}
			} else if prop.ValueRange != nil {
				d.fanLevelValues = rangeValues(prop.ValueRange)
			}
		}
	}
	if s, p, ok := resolver.find("horizontal-swing"); ok {
		d.propOscillation = siidPiid{s, p, true}
	}

	// mode 属性：有 ValueList → 模式选择器，有 ValueRange → 连续值，否则 → 自然风开关
	if s, p, ok := resolver.find("mode"); ok {
		if prop := resolver.prop("mode"); prop != nil {
			if len(prop.ValueList) > 0 {
				d.propMode = siidPiid{s, p, true}
				for _, item := range prop.ValueList {
					d.modeValues = append(d.modeValues, toInt(item.Value))
				}
			} else if prop.ValueRange != nil {
				d.propMode = siidPiid{s, p, true}
				d.modeValues = rangeValues(prop.ValueRange)
			}
		}
		if !d.propMode.valid {
			d.propNaturalWind = siidPiid{s, p, true}
		}
	}

	return d, nil
}

func (d *fanDevice) 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 *fanDevice) 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 *fanDevice) 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 *fanDevice) HasFanLevel() bool { return d.propFanLevel.valid }

func (d *fanDevice) FanLevelValues() []int { return d.fanLevelValues }

func (d *fanDevice) SetFanLevel(ctx context.Context, level int) error {
	if !d.propFanLevel.valid {
		return xiaomi.ErrNotSupported
	}
	return d.SetProp(ctx, d.propFanLevel.siid, d.propFanLevel.piid, level)
}

func (d *fanDevice) GetFanLevel(ctx context.Context) (int, error) {
	if !d.propFanLevel.valid {
		return 0, xiaomi.ErrNotSupported
	}
	prop, err := d.GetProp(ctx, d.propFanLevel.siid, d.propFanLevel.piid)
	if err != nil {
		return 0, err
	}
	return toInt(prop.Value), nil
}

func (d *fanDevice) HasMode() bool { return d.propMode.valid }

func (d *fanDevice) ModeValues() []int { return d.modeValues }

func (d *fanDevice) SetMode(ctx context.Context, mode int) error {
	if !d.propMode.valid {
		return xiaomi.ErrNotSupported
	}
	return d.SetProp(ctx, d.propMode.siid, d.propMode.piid, mode)
}

func (d *fanDevice) GetMode(ctx context.Context) (int, error) {
	if !d.propMode.valid {
		return 0, xiaomi.ErrNotSupported
	}
	prop, err := d.GetProp(ctx, d.propMode.siid, d.propMode.piid)
	if err != nil {
		return 0, err
	}
	return toInt(prop.Value), nil
}

func (d *fanDevice) SetOscillation(ctx context.Context, on bool) error {
	if !d.propOscillation.valid {
		return xiaomi.ErrNotSupported
	}
	return d.SetProp(ctx, d.propOscillation.siid, d.propOscillation.piid, on)
}

func (d *fanDevice) IsOscillating(ctx context.Context) (bool, error) {
	if !d.propOscillation.valid {
		return false, xiaomi.ErrNotSupported
	}
	prop, err := d.GetProp(ctx, d.propOscillation.siid, d.propOscillation.piid)
	if err != nil {
		return false, err
	}
	if b, ok := prop.Value.(bool); ok {
		return b, nil
	}
	return false, nil
}

func (d *fanDevice) SetNaturalWind(ctx context.Context, on bool) error {
	if !d.propNaturalWind.valid {
		return xiaomi.ErrNotSupported
	}
	v := 0
	if on {
		v = 1
	}
	return d.SetProp(ctx, d.propNaturalWind.siid, d.propNaturalWind.piid, v)
}

func (d *fanDevice) IsNaturalWind(ctx context.Context) (bool, error) {
	if !d.propNaturalWind.valid {
		return false, xiaomi.ErrNotSupported
	}
	prop, err := d.GetProp(ctx, d.propNaturalWind.siid, d.propNaturalWind.piid)
	if err != nil {
		return false, err
	}
	return toInt(prop.Value) == 1, nil
}

func (d *fanDevice) OnPropsChanged(handler func(props FanProps, changed string)) (string, error) {
	type field struct {
		siid, piid int
		name       string
		fill       func(*FanProps, interface{})
	}
	var fields []field
	if d.propOn.valid {
		fields = append(fields, field{d.propOn.siid, d.propOn.piid, "on",
			func(s *FanProps, v interface{}) { s.On, _ = v.(bool) }})
	}
	if d.propFanLevel.valid {
		fields = append(fields, field{d.propFanLevel.siid, d.propFanLevel.piid, "fan-level",
			func(s *FanProps, v interface{}) { s.FanLevel = toInt(v) }})
	}
	if d.propMode.valid {
		fields = append(fields, field{d.propMode.siid, d.propMode.piid, "mode",
			func(s *FanProps, v interface{}) { s.Mode = toInt(v) }})
	}
	if d.propOscillation.valid {
		fields = append(fields, field{d.propOscillation.siid, d.propOscillation.piid, "oscillation",
			func(s *FanProps, v interface{}) { s.Oscillation, _ = v.(bool) }})
	}
	if d.propNaturalWind.valid {
		fields = append(fields, field{d.propNaturalWind.siid, d.propNaturalWind.piid, "natural-wind",
			func(s *FanProps, v interface{}) { s.NaturalWind = toInt(v) == 1 }})
	}

	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.propsCache, prop.Value)
				handler(d.propsCache, f.name)
				return
			}
		}
	})
}

func (d *fanDevice) GetProps() FanProps { return d.propsCache }

func (d *fanDevice) FetchProps(ctx context.Context) (FanProps, error) {
	keys := []xiaomi.PropKey{}
	if d.propOn.valid {
		keys = append(keys, xiaomi.PropKey{DID: d.info.DID, SIID: d.propOn.siid, PIID: d.propOn.piid})
	}
	if d.propFanLevel.valid {
		keys = append(keys, xiaomi.PropKey{DID: d.info.DID, SIID: d.propFanLevel.siid, PIID: d.propFanLevel.piid})
	}
	if d.propMode.valid {
		keys = append(keys, xiaomi.PropKey{DID: d.info.DID, SIID: d.propMode.siid, PIID: d.propMode.piid})
	}
	if d.propOscillation.valid {
		keys = append(keys, xiaomi.PropKey{DID: d.info.DID, SIID: d.propOscillation.siid, PIID: d.propOscillation.piid})
	}
	if d.propNaturalWind.valid {
		keys = append(keys, xiaomi.PropKey{DID: d.info.DID, SIID: d.propNaturalWind.siid, PIID: d.propNaturalWind.piid})
	}
	props, err := d.client.GetProps(ctx, keys)
	if err != nil {
		return d.propsCache, err
	}
	result := FanProps{}
	for _, p := range props {
		switch {
		case d.propOn.valid && p.SIID == d.propOn.siid && p.PIID == d.propOn.piid:
			result.On, _ = p.Value.(bool)
		case d.propFanLevel.valid && p.SIID == d.propFanLevel.siid && p.PIID == d.propFanLevel.piid:
			result.FanLevel = toInt(p.Value)
		case d.propMode.valid && p.SIID == d.propMode.siid && p.PIID == d.propMode.piid:
			result.Mode = toInt(p.Value)
		case d.propOscillation.valid && p.SIID == d.propOscillation.siid && p.PIID == d.propOscillation.piid:
			result.Oscillation, _ = p.Value.(bool)
		case d.propNaturalWind.valid && p.SIID == d.propNaturalWind.siid && p.PIID == d.propNaturalWind.piid:
			result.NaturalWind = toInt(p.Value) == 1
		}
	}
	d.propsCache = result
	return result, nil
}

// rangeValues 从 SPEC value-range 生成离散值列表，如 [1,8,1] → [1,2,3,4,5,6,7,8]
func rangeValues(r *miot.MIoTSpecValueRange) []int {
	if r == nil {
		return nil
	}
	min, max, step := toInt(r.Min), toInt(r.Max), toInt(r.Step)
	if step <= 0 {
		step = 1
	}
	if max > 100 {
		return nil // 太大会爆内存，返回 nil 让调用方自行处理
	}
	var vals []int
	for i := min; i <= max; i += step {
		vals = append(vals, i)
	}
	return vals
}