package jetson

import (
	"errors"
	"strings"
	"testing"

	"runtime"
	"strconv"
	"sync"

	"gobot.io/x/gobot"
	"gobot.io/x/gobot/drivers/gpio"
	"gobot.io/x/gobot/drivers/i2c"
	"gobot.io/x/gobot/drivers/spi"
	"gobot.io/x/gobot/gobottest"
	"gobot.io/x/gobot/system"
)

// make sure that this Adaptor fulfills all the required interfaces
var _ gobot.Adaptor = (*Adaptor)(nil)
var _ gobot.DigitalPinnerProvider = (*Adaptor)(nil)
var _ gobot.PWMPinnerProvider = (*Adaptor)(nil)
var _ gpio.DigitalReader = (*Adaptor)(nil)
var _ gpio.DigitalWriter = (*Adaptor)(nil)
var _ i2c.Connector = (*Adaptor)(nil)
var _ spi.Connector = (*Adaptor)(nil)

func initTestAdaptorWithMockedFilesystem(mockPaths []string) (*Adaptor, *system.MockFilesystem) {
	a := NewAdaptor()
	fs := a.sys.UseMockFilesystem(mockPaths)
	if err := a.Connect(); err != nil {
		panic(err)
	}
	return a, fs
}

func TestNewAdaptor(t *testing.T) {
	a := NewAdaptor()

	gobottest.Assert(t, strings.HasPrefix(a.Name(), "JetsonNano"), true)
	gobottest.Assert(t, a.GetDefaultBus(), 1)

	a.SetName("NewName")
	gobottest.Assert(t, a.Name(), "NewName")
}

func TestFinalize(t *testing.T) {
	mockPaths := []string{
		"/sys/class/gpio/export",
		"/sys/class/gpio/unexport",
		"/dev/i2c-1",
		"/dev/i2c-0",
		"/dev/spidev0.0",
		"/dev/spidev0.1",
	}
	a, _ := initTestAdaptorWithMockedFilesystem(mockPaths)

	a.DigitalWrite("3", 1)

	a.GetConnection(0xff, 0)
	gobottest.Assert(t, a.Finalize(), nil)
}

func TestPWMPinsConnect(t *testing.T) {
	a := NewAdaptor()
	gobottest.Assert(t, a.pwmPins, (map[string]gobot.PWMPinner)(nil))

	err := a.PwmWrite("33", 1)
	gobottest.Assert(t, err.Error(), "not connected")

	err = a.Connect()
	gobottest.Assert(t, err, nil)
	gobottest.Refute(t, a.pwmPins, (map[string]gobot.PWMPinner)(nil))
	gobottest.Assert(t, len(a.pwmPins), 0)
}

func TestPWMPinsReConnect(t *testing.T) {
	// arrange
	mockPaths := []string{
		"/sys/class/pwm/pwmchip0/export",
		"/sys/class/pwm/pwmchip0/unexport",
		"/sys/class/pwm/pwmchip0/pwm2/duty_cycle",
		"/sys/class/pwm/pwmchip0/pwm2/period",
		"/sys/class/pwm/pwmchip0/pwm2/enable",
	}
	a, _ := initTestAdaptorWithMockedFilesystem(mockPaths)
	gobottest.Assert(t, len(a.pwmPins), 0)
	gobottest.Assert(t, a.PwmWrite("33", 1), nil)
	gobottest.Assert(t, len(a.pwmPins), 1)
	gobottest.Assert(t, a.Finalize(), nil)
	// act
	err := a.Connect()
	// assert
	gobottest.Assert(t, err, nil)
	gobottest.Assert(t, len(a.pwmPins), 0)
}

func TestDigitalIO(t *testing.T) {
	mockPaths := []string{
		"/sys/class/gpio/export",
		"/sys/class/gpio/unexport",
		"/sys/class/gpio/gpio216/value",
		"/sys/class/gpio/gpio216/direction",
		"/sys/class/gpio/gpio14/value",
		"/sys/class/gpio/gpio14/direction",
	}
	a, fs := initTestAdaptorWithMockedFilesystem(mockPaths)

	err := a.DigitalWrite("7", 1)
	gobottest.Assert(t, err, nil)
	gobottest.Assert(t, fs.Files["/sys/class/gpio/gpio216/value"].Contents, "1")

	err = a.DigitalWrite("13", 1)
	gobottest.Assert(t, err, nil)
	i, err := a.DigitalRead("13")
	gobottest.Assert(t, err, nil)
	gobottest.Assert(t, i, 1)

	gobottest.Assert(t, a.DigitalWrite("notexist", 1), errors.New("'notexist' is not a valid id for a digital pin"))
	gobottest.Assert(t, a.Finalize(), nil)
}

func TestI2c(t *testing.T) {
	a, _ := initTestAdaptorWithMockedFilesystem([]string{"/dev/i2c-1"})
	a.sys.UseMockSyscall()

	con, err := a.GetConnection(0xff, 1)
	gobottest.Assert(t, err, nil)

	_, err = con.Write([]byte{0x00, 0x01})
	gobottest.Assert(t, err, nil)

	data := []byte{42, 42}
	_, err = con.Read(data)
	gobottest.Assert(t, err, nil)
	gobottest.Assert(t, data, []byte{0x00, 0x01})

	_, err = a.GetConnection(0xff, 51)
	gobottest.Assert(t, err, errors.New("Bus number 51 out of range"))

	gobottest.Assert(t, a.GetDefaultBus(), 1)
}

func TestSPI(t *testing.T) {
	a := NewAdaptor()

	gobottest.Assert(t, a.GetSpiDefaultBus(), 0)
	gobottest.Assert(t, a.GetSpiDefaultChip(), 0)
	gobottest.Assert(t, a.GetSpiDefaultMode(), 0)
	gobottest.Assert(t, a.GetSpiDefaultMaxSpeed(), int64(10000000))

	_, err := a.GetSpiConnection(10, 0, 0, 8, 10000000)
	gobottest.Assert(t, err.Error(), "Bus number 10 out of range")

	// TODO: tests for real connection currently not possible, because not using system.Accessor using
	// TODO: test tx/rx here...
}

func TestDigitalPinConcurrency(t *testing.T) {

	oldProcs := runtime.GOMAXPROCS(0)
	runtime.GOMAXPROCS(8)
	defer runtime.GOMAXPROCS(oldProcs)

	for retry := 0; retry < 20; retry++ {

		a := NewAdaptor()
		var wg sync.WaitGroup

		for i := 0; i < 20; i++ {
			wg.Add(1)
			pinAsString := strconv.Itoa(i)
			go func(pin string) {
				defer wg.Done()
				a.DigitalPin(pin)
			}(pinAsString)
		}

		wg.Wait()
	}
}