package mk2driver

import "time"

type Led int

const (
	LedMain Led = iota
	LedAbsorption
	LedBulk
	LedFloat
	LedInverter
	LedOverload
	LedLowBattery
	LedTemperature
)

var LedNames = map[Led]string{
	LedTemperature: "led_over_temp",
	LedLowBattery:  "led_bat_low",
	LedOverload:    "led_overload",
	LedInverter:    "led_inverter",
	LedFloat:       "led_float",
	LedBulk:        "led_bulk",
	LedAbsorption:  "led_absorb",
	LedMain:        "led_mains",
}

type LEDstate int

const (
	LedOff LEDstate = iota
	LedOn
	LedBlink
)

var StateNames = map[LEDstate]string{
	LedOff:   "off",
	LedOn:    "on",
	LedBlink: "blink",
}

type Mk2Info struct {
	// Will be marked as false if an error is detected.
	Valid bool

	Version uint32

	BatVoltage float64
	// Positive current == charging
	// Negative current == discharging
	BatCurrent float64

	// Input AC parameters
	InVoltage   float64
	InCurrent   float64
	InFrequency float64

	// Output AC parameters
	OutVoltage   float64
	OutCurrent   float64
	OutFrequency float64

	// Charge state 0.0 to 1.0
	ChargeState float64

	// List LEDs
	LEDs map[Led]LEDstate

	Errors []error

	Timestamp time.Time
}

type Mk2 interface {
	C() chan *Mk2Info
	Close()
}

type PanelSwitchState byte

const (
	// PanelSwitchChargerOnly enables charging only.
	PanelSwitchChargerOnly PanelSwitchState = 0x01
	// PanelSwitchInverterOnly enables inverter output and disables charging.
	PanelSwitchInverterOnly PanelSwitchState = 0x02
	// PanelSwitchOn enables both inverter and charger.
	PanelSwitchOn PanelSwitchState = 0x03
	// PanelSwitchOff disables inverter and charger.
	PanelSwitchOff PanelSwitchState = 0x04
)

type SettingsWriter interface {
	// WriteRAMVar writes a signed 16-bit value to a RAM variable id.
	WriteRAMVar(id uint16, value int16) error
	// WriteSetting writes a signed 16-bit value to a setting id.
	WriteSetting(id uint16, value int16) error
	// SetPanelState sends the MK2 "S" command using a virtual panel switch state.
	// If currentLimitA is nil, the command does not update the AC current limit.
	SetPanelState(switchState PanelSwitchState, currentLimitA *float64) error
	// SetStandby configures the remote panel standby line.
	// When enabled, the inverter is prevented from sleeping while switched off.
	SetStandby(enabled bool) error
}

type DeviceState byte

const (
	// DeviceStateChargerOnly enables charging only.
	DeviceStateChargerOnly DeviceState = 0x02
	// DeviceStateInverterOnly enables inverter output and disables charging.
	DeviceStateInverterOnly DeviceState = 0x03
	// DeviceStateOn enables both inverter and charger.
	DeviceStateOn DeviceState = 0x04
	// DeviceStateOff disables inverter and charger.
	DeviceStateOff DeviceState = 0x05
)

var DeviceStateNames = map[DeviceState]string{
	DeviceStateChargerOnly:  "charger_only",
	DeviceStateInverterOnly: "inverter_only",
	DeviceStateOn:           "on",
	DeviceStateOff:          "off",
}

type RAMVarInfo struct {
	ID        uint16
	Scale     int16
	Offset    int16
	Factor    float64
	Signed    bool
	Supported bool
}

// ProtocolControl exposes protocol 3.14 command paths for direct MK2 control.
type ProtocolControl interface {
	SettingsWriter
	// GetDeviceState returns the current VE.Bus state using command 0x0E.
	GetDeviceState() (DeviceState, error)
	// SetDeviceState sets the VE.Bus state using command 0x0E.
	SetDeviceState(state DeviceState) error
	// ReadRAMVarByID reads a RAM variable via command 0x30.
	ReadRAMVarByID(id uint16) (int16, error)
	// ReadSettingByID reads a setting via command 0x31.
	ReadSettingByID(id uint16) (int16, error)
	// SelectRAMVar selects a RAM variable for follow-up read-selected/write-selected paths.
	SelectRAMVar(id uint16) error
	// SelectSetting selects a setting for follow-up read-selected/write-selected paths.
	SelectSetting(id uint16) error
	// ReadSelected reads the currently selected value via command 0x35.
	ReadSelected() (int16, error)
	// ReadRAMVarInfo reads RAM variable metadata via command 0x36.
	ReadRAMVarInfo(id uint16) (RAMVarInfo, error)
	// WriteSettingByID writes a setting via command 0x37.
	WriteSettingByID(id uint16, value int16) error
	// WriteRAMVarByID writes a RAM variable via command 0x38.
	WriteRAMVarByID(id uint16, value int16) error
}