package meter

//go:generate go tool decorate -f decorateHomeAssistant -b *HomeAssistant -r api.Meter -t "api.MeterEnergy,TotalEnergy,func() (float64, error)" -t "api.PhaseCurrents,Currents,func() (float64, float64, float64, error)" -t "api.PhaseVoltages,Voltages,func() (float64, float64, float64, error)" -t "api.Battery,Soc,func() (float64, error)" -t "api.BatteryCapacity,Capacity,func() float64" -t "api.BatterySocLimiter,GetSocLimits,func() (float64, float64)" -t "api.BatteryPowerLimiter,GetPowerLimits,func() (float64, float64)" -t "api.BatteryController,SetBatteryMode,func(api.BatteryMode) error" -t "api.MaxACPowerGetter,MaxACPower,func() float64"

import (
	"errors"
	"fmt"

	"github.com/evcc-io/evcc/api"
	"github.com/evcc-io/evcc/util"
	"github.com/evcc-io/evcc/util/homeassistant"
)

// HomeAssistant meter implementation
type HomeAssistant struct {
	conn  *homeassistant.Connection
	power string
}

func init() {
	registry.Add("homeassistant", NewHomeAssistantFromConfig)
}

// NewHomeAssistantFromConfig creates a HomeAssistant meter from generic config
func NewHomeAssistantFromConfig(other map[string]any) (api.Meter, error) {
	cc := struct {
		_URI     string `mapstructure:"uri"`   // TODO deprecated
		_Token   string `mapstructure:"token"` // TODO deprecated
		Home     string
		Power    string
		Energy   string
		Currents []string
		Voltages []string
		Soc      string

		// pv
		pvMaxACPower `mapstructure:",squash"`

		// battery
		batteryCapacity    `mapstructure:",squash"`
		batterySocLimits   `mapstructure:",squash"`
		batteryPowerLimits `mapstructure:",squash"`
	}{
		Home: "Home",
		batterySocLimits: batterySocLimits{
			MinSoc: 20,
			MaxSoc: 95,
		},
	}

	if err := util.DecodeOther(other, &cc); err != nil {
		return nil, err
	}

	if cc.Power == "" {
		return nil, errors.New("missing power sensor entity")
	}

	log := util.NewLogger("ha-meter")
	conn, err := homeassistant.NewConnection(log, cc.Home)
	if err != nil {
		return nil, err
	}

	m := &HomeAssistant{
		conn:  conn,
		power: cc.Power,
	}

	// decorators for optional interfaces
	var energy func() (float64, error)
	var currents, voltages func() (float64, float64, float64, error)
	var soc func() (float64, error)

	if cc.Energy != "" {
		energy = func() (float64, error) { return conn.GetFloatState(cc.Energy) }
	}

	// phase currents (optional)
	if phases, err := homeassistant.ValidatePhaseEntities(cc.Currents); len(phases) > 0 {
		currents = func() (float64, float64, float64, error) { return conn.GetPhaseFloatStates(phases) }
	} else if err != nil {
		return nil, fmt.Errorf("currents: %w", err)
	}

	// phase voltages (optional)
	if phases, err := homeassistant.ValidatePhaseEntities(cc.Voltages); len(phases) > 0 {
		voltages = func() (float64, float64, float64, error) { return conn.GetPhaseFloatStates(phases) }
	} else if err != nil {
		return nil, fmt.Errorf("voltages: %w", err)
	}

	if cc.Soc != "" {
		soc = func() (float64, error) { return conn.GetFloatState(cc.Soc) }
	}

	return decorateHomeAssistant(m,
		energy, currents, voltages, soc,
		cc.batteryCapacity.Decorator(), cc.batterySocLimits.Decorator(), cc.batteryPowerLimits.Decorator(), nil,
		cc.pvMaxACPower.Decorator(),
	), nil
}

var _ api.Meter = (*HomeAssistant)(nil)

// CurrentPower implements the api.Meter interface
func (m *HomeAssistant) CurrentPower() (float64, error) {
	return m.conn.GetFloatState(m.power)
}