balazsgrill/wscgo

package devices

import (
    "sync"

    "periph.io/x/conn/v3/gpio"
    "periph.io/x/conn/v3/gpio/gpioreg"
)

// ShutterStateListener is the signature for state callback
type ShutterStateListener func(int)

// IShutter is the interface of a shutter device
type IShutter interface {
    Device
    Open()
    Close()
    OpenOrStop()
    CloseOrStop()
    MoveBy(int)
    Stop()
    GetRange() int
    AddListener(ShutterStateListener)
}

// ShutterConfig holds the configuration values for a shutter
type ShutterConfig struct {
    UpPin         string `ini:"uppin"`
    DownPin       string `ini:"downpin"`
    DirSwitchWait int    `ini:"dirswitchwait"`
    Range         int    `ini:"range"`
    Inverted      bool   `ini:"inverted"`
}

type shutter struct {
    lock sync.Mutex

    upPin   gpio.PinOut
    downPin gpio.PinOut
    config  *ShutterConfig
    Cmd     int
    Wait    int

    Current int
    Prev    int

    PrevDir     int
    firstCmd    bool
    stopCounter int
    shouldWait  bool

    listeners []ShutterStateListener
}

// CreateShutter configures a shutter device
func CreateShutter(config *ShutterConfig) (IShutter, error) {
    uppin := gpioreg.ByName(config.UpPin)
    if uppin == nil {
        return nil, invalidPinError(config.UpPin)
    }
    uppin = CachedPin(uppin, 100)
    downpin := gpioreg.ByName(config.DownPin)
    if downpin == nil {
        return nil, invalidPinError(config.DownPin)
    }
    downpin = CachedPin(downpin, 100)
    return &shutter{
        upPin:       uppin,
        downPin:     downpin,
        config:      config,
        Current:     0,
        Prev:        0,
        PrevDir:     0,
        firstCmd:    true,
        stopCounter: 0,
        shouldWait:  false,
    }, nil
}

func (shutter *shutter) getRealLevel(level gpio.Level) gpio.Level {
    if shutter.config.Inverted {
        return !level
    }
    return level
}

func (shutter *shutter) fireEvent() {
    for _, listener := range shutter.listeners {
        go listener(shutter.Current)
    }
}

func (shutter *shutter) up() error {
    err := shutter.downPin.Out(shutter.getRealLevel(gpio.Low)) // turn off down
    if err != nil {
        return err
    }
    return shutter.upPin.Out(shutter.getRealLevel(gpio.High)) // turn on up
}

func (shutter *shutter) down() error {
    err := shutter.upPin.Out(shutter.getRealLevel(gpio.Low)) // turn off up
    if err != nil {
        return err
    }
    return shutter.downPin.Out(shutter.getRealLevel(gpio.High)) // turn on down
}

func (shutter *shutter) stop() error {
    err := shutter.upPin.Out(shutter.getRealLevel(gpio.Low)) // turn off up
    if err != nil {
        return err
    }
    return shutter.downPin.Out(shutter.getRealLevel(gpio.Low)) // turn on down
}

func (shutter *shutter) Initialize() error {
    shutter.Prev = -1
    return shutter.stop()
}

func (shutter *shutter) setCmd(steps int, stopIfDirchange bool) {
    shutter.lock.Lock()
    defer shutter.lock.Unlock()
    if steps == 0 {
        //stop
        shutter.Cmd = 0
        if shutter.PrevDir != 0 && !shutter.firstCmd {
            shutter.Wait = shutter.config.DirSwitchWait
        } else {
            //shutter.PrevDir = 0
        }
    } else if steps > 0 {
        //up
        if shutter.Cmd < 0 {
            // direction change
            if stopIfDirchange {
                shutter.Cmd = 0
            } else {
                shutter.Cmd = steps
            }
            shutter.Wait = shutter.config.DirSwitchWait
        } else {
            shutter.Cmd += steps
        }

        if (shutter.PrevDir != 1 && shutter.PrevDir != 0 && !shutter.firstCmd) || (shutter.shouldWait && shutter.PrevDir != 1) {
            shutter.Wait = shutter.config.DirSwitchWait - shutter.stopCounter
        }

        shutter.PrevDir = 1
    } else {
        //down
        if shutter.Cmd > 0 {
            //direction change
            if stopIfDirchange {
                shutter.Cmd = 0
            } else {
                shutter.Cmd = steps
            }
            shutter.Wait = shutter.config.DirSwitchWait
        } else {
            shutter.Cmd += steps
        }

        if (shutter.PrevDir != -1 && shutter.PrevDir != 0 && !shutter.firstCmd) || (shutter.shouldWait && shutter.PrevDir != -1) {
            shutter.Wait = shutter.config.DirSwitchWait - shutter.stopCounter
        }

        shutter.PrevDir = -1
    }

    shutter.firstCmd = false
}

func (shutter *shutter) Tick() error {
    shutter.lock.Lock()
    defer shutter.lock.Unlock()
    if shutter.Wait > 0 {
        shutter.Wait--
        if shutter.Wait == 0 {
            shutter.PrevDir = 0
        }
        return shutter.stop()
    }
    if shutter.Cmd == 0 {
        if shutter.stopCounter <= shutter.config.DirSwitchWait && shutter.shouldWait {
            shutter.stopCounter++
        }
        if shutter.stopCounter >= shutter.config.DirSwitchWait {
            shutter.shouldWait = false
        } else {
            shutter.shouldWait = true
        }
        return shutter.stop()
    }
    defer shutter.fireEvent()
    shutter.stopCounter = 0
    if shutter.Cmd > 0 {
        shutter.Cmd--
        shutter.Current++
        if shutter.Current > shutter.config.Range {
            shutter.Current = shutter.config.Range
        }
        shutter.PrevDir = 1
        return shutter.up()
    }
    shutter.Cmd++
    shutter.Current--
    if shutter.Current < 0 {
        shutter.Current = 0
    }
    shutter.PrevDir = -1
    return shutter.down()
}

func (shutter *shutter) AddListener(listener ShutterStateListener) {
    shutter.listeners = append(shutter.listeners, listener)
}

func (shutter *shutter) Open() {
    shutter.setCmd(shutter.config.Range, false)
}
func (shutter *shutter) Close() {
    shutter.setCmd(-shutter.config.Range, false)
}
func (shutter *shutter) OpenOrStop() {
    shutter.setCmd(shutter.config.Range, true)
}
func (shutter *shutter) CloseOrStop() {
    shutter.setCmd(-shutter.config.Range, true)
}
func (shutter *shutter) MoveBy(steps int) {
    shutter.setCmd(steps, false)
}
func (shutter *shutter) Stop() {
    shutter.setCmd(0, false)
}
func (shutter *shutter) GetRange() int {
    return shutter.config.Range
}