main.go

package main

import (
	"log"
	"os"
	"path/filepath"
	"regexp"
	"time"

	"github.com/morphar/remotepi/pkg/rc5"
	"github.com/stianeikeland/go-rpio/v4"
)

func init() {
	log.SetFlags(log.Ltime | log.Lshortfile)
}

// $ cat /proc/asound/card0/pcm*/sub*/status
// closed

// $ cat /proc/asound/card0/pcm*/sub*/status
// state: RUNNING

// The regexp for matching ON state of the audio stream
var reRunning = regexp.MustCompile("state: RUNNING")

func main() {
	// Open pin with the remote control rca connected
	err := rpio.Open()
	exitOnErr(err)
	defer rpio.Close()

	// Currently only supports pin 17
	pin := rpio.Pin(17)
	defer pin.Low()

	// Create a couple of amplifier rc commands
	// onOff := rc5Command(16, 12, 0)
	// volumeUp := rc5Command(16, 16, 0)
	// volumeDown := rc5Command(16, 17, 0)
	turnOn := rc5.CommandX(16, 12, 1, 0)
	turnOff := rc5.CommandX(16, 12, 2, 0)
	// directVolume := rc5xCommand(16, 111, 10, 0)

	// onOff := 0b11010000001100
	// turnOff := 0b1101000000001100000010
	// sendSignal(pin, uint(onOff), true)

	// Delays before turning on or off the amplifier
	offDeleay := 2 * time.Minute

	// Find all audio card status files (hopefully only 1)
	statusFiles, err := filepath.Glob("/proc/asound/card0/pcm*/sub*/status")
	exitOnErr(err)

	// if len(matches) != 1 {
	// 	log.Fatal("For now, this only works with 1 audio card")
	// }

	// statusFile := matches[0]

	// Setup the check vars
	var lastOn time.Time
	var stateOn bool

	for {
		// Find the current state - more specifically: is any cards running?
		curStateOn := false
		for _, statusFile := range statusFiles {
			src, err := os.ReadFile(statusFile)
			exitOnErr(err)
			if reRunning.Match(src) {
				curStateOn = true
				break
			}
		}

		// cur state is on, update the lastOn timestamp
		if curStateOn {
			lastOn = time.Now()
		}

		// If any card is running and the state is not on: send the ON signal
		if curStateOn && !stateOn {
			stateOn = true
			rc5.Send(pin, turnOn, true)
			time.Sleep(time.Second)
			pin.Input()
			pin.PullOff()
			continue
		}

		// If the current state is off and the off delay has passed since last on: send the OFF signal
		if !curStateOn && stateOn && time.Since(lastOn) > offDeleay {
			stateOn = false
			rc5.Send(pin, turnOff, true)
			pin.Input()
			pin.PullOff()
		}

		time.Sleep(time.Second)
	}
}

func exitOnErr(err error) {
	if err != nil {
		log.Fatal(err)
	}
}