package PinControlService

import (
	"errors"
	log "github.com/sirupsen/logrus"
)

type Pin struct {
	Id                int
	Name              string
	Direction         PinDirection
	PullConfig        *PinPull
	InitialState      *PinCommand
	PinHandle         HardwarePinInterface
	SendPollingEvents bool
	SendChangeEvents  bool
}

func NewPin(config PinConfig) Pin {
	p := Pin{
		Direction:  config.Direction,
		PullConfig: config.PullConfig,
		Name:       config.Name,
		Id:         config.PinNumber,
		PinHandle:  NewHardwarePin(config.PinNumber),
	}

	if config.SendPollingEvents != nil {
		p.SendPollingEvents = *config.SendPollingEvents
	} else {
		p.SendPollingEvents = true
	}

	if config.SendChangeEvents != nil {
		p.SendChangeEvents = *config.SendChangeEvents
	} else {
		p.SendChangeEvents = true
	}

	p.InitialState = config.InitialState

	return p
}

func (p *Pin) State() PinState {
	if state := p.PinHandle.Read(); State(state) == HighState {
		return StateOn
	} else {
		return StateOff
	}
}

func (p *Pin) Command(cmd PinCommand) error {
	log.Infof("send command \"%s\" for pin %s (pin no: %d)", cmd, p.Name, p.Id)
	if p.Direction != Output {
		return errors.New("pin is not an output")
	}

	if cmd == On {
		p.PinHandle.High()
	} else if cmd == Off {
		p.PinHandle.Low()
	} else if cmd == Toggle {
		p.PinHandle.Toggle()
	} else {
		return errors.New("unknown command")
	}

	return nil
}

func (p *Pin) Configure() {
	if p.PullConfig != nil {
		log.Infof("configuring Pull Resistor for pin %s (pin no: %d) as %s", p.Name, p.Id, *p.PullConfig)
		if *p.PullConfig == PullUp {
			p.PinHandle.PullUp()
		} else if *p.PullConfig == PullDown {
			p.PinHandle.PullDown()
		} else if *p.PullConfig == PullOff {
			p.PinHandle.PullOff()
		} else {
			log.Errorf("unknown config value \"%s\" for pull-config", *p.PullConfig)
		}
	}

	if p.Direction == Input {
		log.Infof("configuring pin %s (pin no: %d) as Input", p.Name, p.Id)
		p.PinHandle.Input()
		p.PinHandle.Detect(AnyEdge)
	} else if p.Direction == Output {
		log.Infof("configuring pin %s (pin no: %d) as Output", p.Name, p.Id)
		p.PinHandle.Output()
		if p.InitialState != nil {
			log.Infof("set initial state \"%s\" for pin %s (pin no: %d)", *p.InitialState, p.Name, p.Id)
			_ = p.Command(*p.InitialState)
		}
	}
}

func (p *Pin) Changed() bool {
	ret := p.PinHandle.EdgeDetected()
	if ret {
		log.Infof("pin %s (pin no: %d) changed state", p.Name, p.Id)
	}
	return ret
}