package smartfanunit

import (
	"errors"

	"github.com/compute-blade-community/compute-blade-agent/pkg/hal/led"
	"github.com/compute-blade-community/compute-blade-agent/pkg/smartfanunit/proto"
)

// Blade -> FanUnit communication
const (
	// CmdSetFanSpeedPercent sets the fan speed as a percentage, sent from the blade to the fan unit.
	CmdSetFanSpeedPercent proto.Command = 0x01

	// CmdSetLED represents the command to set the LED color, sent from the blade to the fan unit.
	CmdSetLED proto.Command = 0x02
)

// FanUnit -> Blade, sent in regular intervals
const (
	// NotifyButtonPress represents a command sent from the fan unit to indicate a button press event.
	NotifyButtonPress proto.Command = 0xa1

	// NotifyAirFlowTemperature represents a command sent from the fan unit to report the current air flow temperature.
	NotifyAirFlowTemperature proto.Command = 0xa2

	// NotifyFanSpeedRPM is a command used to report the current fan speed in RPM from the fan unit to the blade.
	NotifyFanSpeedRPM proto.Command = 0xa3
)

var ErrInvalidCommand = errors.New("invalid command")

type PacketGenerator interface {
	Packet() proto.Packet
}

// SetFanSpeedPercentPacket is sent from the blade to the fan unit to set the fan speed in percent.
type SetFanSpeedPercentPacket struct {
	Percent uint8
}

func (p *SetFanSpeedPercentPacket) Packet() proto.Packet {
	return proto.Packet{
		Command: CmdSetFanSpeedPercent,
		Data:    proto.Data{p.Percent, 0, 0},
	}
}

func (p *SetFanSpeedPercentPacket) FromPacket(packet proto.Packet) error {
	if packet.Command != CmdSetFanSpeedPercent {
		return ErrInvalidCommand
	}
	p.Percent = packet.Data[0]
	return nil
}

// SetLEDPacket is sent from the blade to the fan unit to set the LED color.
type SetLEDPacket struct {
	Color led.Color
}

func (p *SetLEDPacket) Packet() proto.Packet {
	return proto.Packet{
		Command: CmdSetLED,
		Data:    proto.Data{p.Color.Blue, p.Color.Green, p.Color.Red},
	}
}

func (p *SetLEDPacket) FromPacket(packet proto.Packet) error {
	if packet.Command != CmdSetLED {
		return ErrInvalidCommand
	}
	p.Color = led.Color{
		Blue:  packet.Data[0],
		Green: packet.Data[1],
		Red:   packet.Data[2],
	}
	return nil
}

// ButtonPressPacket is sent from the fan unit to the blade when the button is pressed.
type ButtonPressPacket struct{}

func (p *ButtonPressPacket) Packet() proto.Packet {
	return proto.Packet{
		Command: NotifyButtonPress,
		Data:    proto.Data{},
	}
}

func (p *ButtonPressPacket) FromPacket(packet proto.Packet) error {
	if packet.Command != NotifyButtonPress {
		return ErrInvalidCommand
	}
	return nil
}

// AirFlowTemperaturePacket is sent from the fan unit to the blade to report the current air flow temperature.
type AirFlowTemperaturePacket struct {
	Temperature float32
}

func (p *AirFlowTemperaturePacket) Packet() proto.Packet {
	return proto.Packet{
		Command: NotifyAirFlowTemperature,
		Data:    float32To24Bit(p.Temperature),
	}
}

func (p *AirFlowTemperaturePacket) FromPacket(packet proto.Packet) error {
	if packet.Command != NotifyAirFlowTemperature {
		return ErrInvalidCommand
	}
	p.Temperature = float32From24Bit(packet.Data)
	return nil
}

// FanSpeedRPMPacket is sent from the fan unit to the blade to report the current fan speed in RPM.
type FanSpeedRPMPacket struct {
	RPM float32
}

func (p *FanSpeedRPMPacket) Packet() proto.Packet {
	return proto.Packet{
		Command: NotifyFanSpeedRPM,
		Data:    float32To24Bit(p.RPM),
	}
}
func (p *FanSpeedRPMPacket) FromPacket(packet proto.Packet) error {
	if packet.Command != NotifyFanSpeedRPM {
		return ErrInvalidCommand
	}
	p.RPM = float32From24Bit(packet.Data)
	return nil
}