package main

import (
	"fmt"
	"log"
	"runtime"
	"unsafe"

	ndk "git.wow.st/gmp/android-go/android27"
)

var (
	tag *ndk.Char
)

func apiLevel() {
	msg := ndk.CharWithGoString("hello log world")
	ndk.AndroidLogWrite(ndk.ANDROID_LOG_WARN, tag, msg)
	msg.Free()

	apilevel := ndk.AndroidGetDeviceApiLevel()
	message := fmt.Sprintf("API level is %d", apilevel)
	labchan <- message

	msg = ndk.CharWithGoString(message)
	ndk.AndroidLogWrite(ndk.ANDROID_LOG_WARN, tag, msg)
	msg.Free()
}

func sensorLoop() {
	// the Android Looper is thread-local
	runtime.LockOSThread()

	pkg := ndk.CharWithGoString("st.wow.git.sensors")
	manager := ndk.ASensorManagerGetInstanceForPackage(pkg)
	pkg.Free()

	sens := ndk.ASensorManagerGetDefaultSensor(manager, ndk.ASENSOR_TYPE_ACCELEROMETER)
	stp := ndk.ASensorGetStringType(sens)
	labchan <- "sensor" + stp.String()

	var looper *ndk.ALooper
	var queue *ndk.ASensorEventQueue
	looper_id := 1
	var rate ndk.Int32_t = 60

	setup := func() {
		looper = ndk.ALooperForThread()
		if (looper == nil) {
			labchan <- "no looper for thread"
			looper = ndk.ALooperPrepare(ndk.ALOOPER_PREPARE_ALLOW_NON_CALLBACKS)
		}

		queue = ndk.ASensorManagerCreateEventQueue(manager, looper, looper_id)

		ndk.ASensorEventQueueEnableSensor(queue, sens)
		ndk.ASensorEventQueueSetEventRate(queue, sens, 1000000/rate) // microseconds
	}

	setup()
	labchan <- "polling accelerometer"
	for {
		var zero ndk.Int
		id := (int)(ndk.ALooperPollOnce(-1, &zero, &zero, (*unsafe.Pointer)(unsafe.Pointer(nil)))) // poll forever
		if (id == ndk.ALOOPER_POLL_ERROR) { // set up a new looper
			labchan <- "getting a new looper"
			setup()
			continue
		}
		if (id == looper_id) {
			var event ndk.ASensorEvent
			if (ndk.ASensorEventQueueGetEvents(queue, &event, 1) != 1) {
				continue
			}
			accel := (&event).Acceleration()
			senschan <- vector{float64(accel.X()), float64(accel.Y()), float64(accel.Z())}
		}
	}
}

func init() {
	tag = ndk.CharWithGoString("gio")
	log.Print("Android starting")
	go apiLevel()
	go sensorLoop()
}