package gpio

import (
	"fmt"
	"strings"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"gobot.io/x/gobot/v2/drivers/aio"
)

func initTestEasyDriverWithStubbedAdaptor() (*EasyDriver, *gpioTestAdaptor) {
	const anglePerStep = 0.5 // use non int step angle to check int math

	a := newGpioTestAdaptor()
	d := NewEasyDriver(a, anglePerStep, "1")
	return d, a
}

func TestNewEasyDriver(t *testing.T) {
	// arrange
	const anglePerStep = 0.5 // use non int step angle to check int math

	a := newGpioTestAdaptor()
	// act
	d := NewEasyDriver(a, anglePerStep, "1")
	// assert
	assert.IsType(t, &EasyDriver{}, d)
	// assert: gpio.driver attributes
	require.NotNil(t, d.driver)
	assert.True(t, strings.HasPrefix(d.driverCfg.name, "EasyDriver"))
	assert.Equal(t, a, d.connection)
	require.NoError(t, d.afterStart())
	require.NoError(t, d.beforeHalt())
	assert.NotNil(t, d.Commander)
	assert.NotNil(t, d.mutex)
	// assert: driver specific attributes
	assert.Equal(t, "1", d.stepPin)
	assert.InDelta(t, float32(anglePerStep), d.anglePerStep, 0.0)
	assert.Equal(t, uint(14), d.speedRpm)
	assert.Equal(t, "forward", d.direction)
	assert.Equal(t, 0, d.stepNum)
	assert.False(t, d.disabled)
	assert.False(t, d.sleeping)
	assert.Nil(t, d.stopAsynchRunFunc)
	require.NotNil(t, d.easyCfg)
	assert.Empty(t, d.easyCfg.dirPin)
	assert.Empty(t, d.easyCfg.enPin)
	assert.Empty(t, d.easyCfg.sleepPin)
}

func TestNewEasyDriver_options(t *testing.T) {
	// This is a general test, that options are applied in constructor by using the common WithName() option, least one
	// option of this driver and one of another driver (which should lead to panic). Further tests for options can also
	// be done by call of "WithOption(val).apply(cfg)".
	// arrange
	const (
		myName = "front wheel"
		dirPin = "2"
	)
	panicFunc := func() {
		NewEasyDriver(newGpioTestAdaptor(), 0.1, "1", WithName("crazy"),
			aio.WithActuatorScaler(func(float64) int { return 0 }))
	}
	// act
	d := NewEasyDriver(newGpioTestAdaptor(), 0.2, "1", WithName(myName), WithEasyDirectionPin(dirPin))
	// assert
	assert.Equal(t, dirPin, d.easyCfg.dirPin)
	assert.Equal(t, myName, d.Name())
	assert.PanicsWithValue(t, "'scaler option for analog actuators' can not be applied on 'crazy', "+
		"consider to use one of the options instead: WithEasyDirectionPin, WithEasyEnablePin, WithEasySleepPin", panicFunc)
}

func TestEasy_WithEasyEnablePin(t *testing.T) {
	// arrange
	const myEnablePin = "3"
	cfg := easyConfiguration{}
	// act
	WithEasyEnablePin(myEnablePin).apply(&cfg)
	// assert
	assert.Equal(t, myEnablePin, cfg.enPin)
}

func TestEasy_WithEasySleepPin(t *testing.T) {
	// arrange
	const mySleepPin = "4"
	cfg := easyConfiguration{}
	// act
	WithEasySleepPin(mySleepPin).apply(&cfg)
	// assert
	assert.Equal(t, mySleepPin, cfg.sleepPin)
}

func TestEasyMoveDeg_IsMoving(t *testing.T) {
	tests := map[string]struct {
		inputDeg               int
		simulateDisabled       bool
		simulateAlreadyRunning bool
		simulateWriteErr       bool
		wantWrites             int
		wantSteps              int
		wantMoving             bool
		wantErr                string
	}{
		"move_one": {
			inputDeg:   1,
			wantWrites: 4,
			wantSteps:  2,
			wantMoving: false,
		},
		"move_more": {
			inputDeg:   20,
			wantWrites: 80,
			wantSteps:  40,
			wantMoving: false,
		},
		"error_disabled": {
			simulateDisabled: true,
			wantMoving:       false,
			wantErr:          "is disabled",
		},
		"error_already_running": {
			simulateAlreadyRunning: true,
			wantMoving:             true,
			wantErr:                "already running or moving",
		},
		"error_write": {
			inputDeg:         1,
			simulateWriteErr: true,
			wantWrites:       0,
			wantMoving:       false,
			wantErr:          "write error",
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			d, a := initTestEasyDriverWithStubbedAdaptor()
			defer func() {
				// for cleanup dangling channels
				if d.stopAsynchRunFunc != nil {
					err := d.stopAsynchRunFunc(true)
					require.NoError(t, err)
				}
			}()
			// arrange: different behavior
			d.disabled = tc.simulateDisabled
			if tc.simulateAlreadyRunning {
				d.stopAsynchRunFunc = func(bool) error { return nil }
			}
			// arrange: writes
			a.written = nil // reset writes of Start()
			a.simulateWriteError = tc.simulateWriteErr
			// act
			err := d.MoveDeg(tc.inputDeg)
			// assert
			if tc.wantErr != "" {
				require.ErrorContains(t, err, tc.wantErr)
			} else {
				require.NoError(t, err)
			}
			assert.Equal(t, tc.wantSteps, d.stepNum)
			assert.Len(t, a.written, tc.wantWrites)
			assert.Equal(t, tc.wantMoving, d.IsMoving())
		})
	}
}

func TestEasyRun_IsMoving(t *testing.T) {
	tests := map[string]struct {
		simulateDisabled       bool
		simulateAlreadyRunning bool
		simulateWriteErr       bool
		wantMoving             bool
		wantErr                string
	}{
		"run": {
			wantMoving: true,
		},
		"error_disabled": {
			simulateDisabled: true,
			wantMoving:       false,
			wantErr:          "is disabled",
		},
		"write_error_skipped": {
			simulateWriteErr: true,
			wantMoving:       true,
		},
		"error_already_running": {
			simulateAlreadyRunning: true,
			wantMoving:             true,
			wantErr:                "already running or moving",
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			d, a := initTestEasyDriverWithStubbedAdaptor()
			d.skipStepErrors = true
			d.disabled = tc.simulateDisabled
			if tc.simulateAlreadyRunning {
				d.stopAsynchRunFunc = func(bool) error { return nil }
			}
			simWriteErr := tc.simulateWriteErr // to prevent data race in write function (go-called)
			a.digitalWriteFunc = func(string, byte) error {
				if simWriteErr {
					simWriteErr = false // to prevent to much output
					return fmt.Errorf("write error")
				}
				return nil
			}
			// act
			err := d.Run()
			// assert
			if tc.wantErr != "" {
				require.ErrorContains(t, err, tc.wantErr)
			} else {
				require.NoError(t, err)
			}
			assert.Equal(t, tc.wantMoving, d.IsMoving())
		})
	}
}

func TestEasyStop_IsMoving(t *testing.T) {
	// arrange
	d, _ := initTestEasyDriverWithStubbedAdaptor()
	require.NoError(t, d.Run())
	require.True(t, d.IsMoving())
	// act
	err := d.Stop()
	// assert
	require.NoError(t, err)
	assert.False(t, d.IsMoving())
}

func TestEasyDriverHalt_IsMoving(t *testing.T) {
	// arrange
	d, _ := initTestEasyDriverWithStubbedAdaptor()
	require.NoError(t, d.Run())
	require.True(t, d.IsMoving())
	// act
	err := d.Halt()
	// assert
	require.NoError(t, err)
	assert.False(t, d.IsMoving())
}

func TestEasySetDirection(t *testing.T) {
	const anglePerStep = 0.5 // use non int step angle to check int math

	tests := map[string]struct {
		input            string
		dirPin           string
		simulateWriteErr bool
		wantVal          string
		wantWritten      byte
		wantErr          string
	}{
		"forward": {
			input:       "forward",
			dirPin:      "10",
			wantWritten: 0,
			wantVal:     "forward",
		},
		"backward": {
			input:       "backward",
			dirPin:      "11",
			wantWritten: 1,
			wantVal:     "backward",
		},
		"unknown": {
			input:       "unknown",
			dirPin:      "12",
			wantWritten: 0xFF,
			wantVal:     "forward",
			wantErr:     "Invalid direction 'unknown'",
		},
		"error_no_pin": {
			input:       "forward",
			dirPin:      "",
			wantWritten: 0xFF,
			wantVal:     "forward",
			wantErr:     "dirPin is not set",
		},
		"error_write": {
			input:            "backward",
			dirPin:           "13",
			simulateWriteErr: true,
			wantWritten:      0xFF,
			wantVal:          "forward",
			wantErr:          "write error",
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			a := newGpioTestAdaptor()
			d := NewEasyDriver(a, anglePerStep, "1", WithEasyDirectionPin(tc.dirPin))
			a.written = nil // reset writes of Start()
			a.simulateWriteError = tc.simulateWriteErr
			require.Equal(t, "forward", d.direction)
			// act
			err := d.SetDirection(tc.input)
			// assert
			if tc.wantErr != "" {
				require.ErrorContains(t, err, tc.wantErr)
			} else {
				require.NoError(t, err)
				assert.Equal(t, tc.dirPin, a.written[0].pin)
				assert.Equal(t, tc.wantWritten, a.written[0].val)
			}
			assert.Equal(t, tc.wantVal, d.direction)
		})
	}
}

func TestEasyMaxSpeed(t *testing.T) {
	const delayForMaxSpeed = 1428 * time.Microsecond // 1/700Hz

	tests := map[string]struct {
		anglePerStep float32
		want         uint
	}{
		"maxspeed_for_20spr": {
			anglePerStep: 360.0 / 20.0,
			want:         2100,
		},
		"maxspeed_for_36spr": {
			anglePerStep: 360.0 / 36.0,
			want:         1166,
		},
		"maxspeed_for_50spr": {
			anglePerStep: 360.0 / 50.0,
			want:         840,
		},
		"maxspeed_for_100spr": {
			anglePerStep: 360.0 / 100.0,
			want:         420,
		},
		"maxspeed_for_400spr": {
			anglePerStep: 360.0 / 400.0,
			want:         105,
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			d, _ := initTestEasyDriverWithStubbedAdaptor()
			d.anglePerStep = tc.anglePerStep
			d.stepsPerRev = 360.0 / tc.anglePerStep
			// act
			got := d.MaxSpeed()
			d.speedRpm = got
			got2 := d.getDelayPerStep()
			// assert
			assert.Equal(t, tc.want, got)
			assert.Equal(t, delayForMaxSpeed.Microseconds()/10, got2.Microseconds()/10)
		})
	}
}

func TestEasySetSpeed(t *testing.T) {
	const (
		anglePerStep = 10
		maxRpm       = 1166
	)

	tests := map[string]struct {
		input   uint
		want    uint
		wantErr string
	}{
		"below_minimum": {
			input:   0,
			want:    0,
			wantErr: "RPM (0) cannot be a zero or negative value",
		},
		"minimum": {
			input: 1,
			want:  1,
		},
		"maximum": {
			input: maxRpm,
			want:  maxRpm,
		},
		"above_maximum": {
			input:   maxRpm + 1,
			want:    maxRpm,
			wantErr: "cannot be greater then maximal value 1166",
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			d, _ := initTestEasyDriverWithStubbedAdaptor()
			d.speedRpm = 0
			d.anglePerStep = anglePerStep
			d.stepsPerRev = 360.0 / anglePerStep
			// act
			err := d.SetSpeed(tc.input)
			// assert
			if tc.wantErr != "" {
				require.ErrorContains(t, err, tc.wantErr)
			} else {
				require.NoError(t, err)
			}
			assert.Equal(t, tc.want, d.speedRpm)
		})
	}
}

func TestEasy_onePinStepping(t *testing.T) {
	tests := map[string]struct {
		countCallsForth  int
		countCallsBack   int
		simulateWriteErr bool
		wantSteps        int
		wantWritten      []gpioTestWritten
		wantErr          string
	}{
		"single": {
			countCallsForth: 1,
			wantSteps:       1,
			wantWritten: []gpioTestWritten{
				{pin: "1", val: 0x00},
				{pin: "1", val: 0x01},
			},
		},
		"many": {
			countCallsForth: 4,
			wantSteps:       4,
			wantWritten: []gpioTestWritten{
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
			},
		},
		"forth_and_back": {
			countCallsForth: 5,
			countCallsBack:  3,
			wantSteps:       2,
			wantWritten: []gpioTestWritten{
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
			},
		},
		"reverse": {
			countCallsBack: 3,
			wantSteps:      -3,
			wantWritten: []gpioTestWritten{
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
				{pin: "1", val: 0x0},
				{pin: "1", val: 0x1},
			},
		},
		"error_write": {
			simulateWriteErr: true,
			countCallsBack:   2,
			wantErr:          "write error",
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			d, a := initTestEasyDriverWithStubbedAdaptor()
			a.written = nil // reset writes of Start()
			a.simulateWriteError = tc.simulateWriteErr
			var errs []string
			// act
			for i := 0; i < tc.countCallsForth; i++ {
				if err := d.onePinStepping(); err != nil {
					errs = append(errs, err.Error())
				}
			}
			d.direction = "backward"
			for i := 0; i < tc.countCallsBack; i++ {
				if err := d.onePinStepping(); err != nil {
					errs = append(errs, err.Error())
				}
			}
			// assert
			if tc.wantErr != "" {
				assert.Contains(t, strings.Join(errs, ","), tc.wantErr)
			} else {
				assert.Nil(t, errs)
			}
			assert.Equal(t, tc.wantSteps, d.stepNum)
			assert.Equal(t, tc.wantSteps, d.CurrentStep())
			assert.Equal(t, tc.wantWritten, a.written)
		})
	}
}

func TestEasyEnable_IsEnabled(t *testing.T) {
	const anglePerStep = 0.5 // use non int step angle to check int math

	tests := map[string]struct {
		enPin            string
		simulateWriteErr bool
		wantWrites       int
		wantEnabled      bool
		wantErr          string
	}{
		"basic": {
			enPin:       "10",
			wantWrites:  1,
			wantEnabled: true,
		},
		"with_run": {
			enPin:       "11",
			wantWrites:  1,
			wantEnabled: true,
		},
		"error_no_pin": {
			enPin:       "",
			wantWrites:  0,
			wantEnabled: true, // is enabled by default
			wantErr:     "enPin is not set",
		},
		"error_write": {
			enPin:            "12",
			simulateWriteErr: true,
			wantWrites:       0,
			wantEnabled:      false,
			wantErr:          "write error",
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			a := newGpioTestAdaptor()
			d := NewEasyDriver(a, anglePerStep, "1", WithEasyEnablePin(tc.enPin))
			a.written = nil // reset writes of Start()
			a.simulateWriteError = tc.simulateWriteErr
			d.disabled = true
			require.False(t, d.IsEnabled())
			// act
			err := d.Enable()
			// assert
			assert.Len(t, a.written, tc.wantWrites)
			if tc.wantErr != "" {
				require.ErrorContains(t, err, tc.wantErr)
			} else {
				require.NoError(t, err)
				assert.Equal(t, tc.enPin, a.written[0].pin)
				assert.Equal(t, byte(0), a.written[0].val) // enable pin is active low
			}
			assert.Equal(t, tc.wantEnabled, d.IsEnabled())
		})
	}
}

func TestEasyDisable_IsEnabled(t *testing.T) {
	const anglePerStep = 0.5 // use non int step angle to check int math

	tests := map[string]struct {
		enPin            string
		runBefore        bool
		simulateWriteErr bool
		wantWrites       int
		wantEnabled      bool
		wantErr          string
	}{
		"basic": {
			enPin:       "10",
			wantWrites:  1,
			wantEnabled: false,
		},
		"with_run": {
			enPin:       "10",
			runBefore:   true,
			wantWrites:  1,
			wantEnabled: false,
		},
		"error_no_pin": {
			enPin:       "",
			wantWrites:  0,
			wantEnabled: true, // is enabled by default
			wantErr:     "enPin is not set",
		},
		"error_write": {
			enPin:            "12",
			simulateWriteErr: true,
			wantWrites:       1,
			wantEnabled:      true,
			wantErr:          "write error",
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			a := newGpioTestAdaptor()
			d := NewEasyDriver(a, anglePerStep, "1", WithEasyEnablePin(tc.enPin))
			var numCallsWrite int
			var writtenPin string
			writtenValue := byte(0xFF)
			a.digitalWriteFunc = func(pin string, val byte) error {
				if pin == d.stepPin {
					// we do not consider call of step()
					return nil
				}
				numCallsWrite++
				writtenPin = pin
				writtenValue = val
				if tc.simulateWriteErr {
					return fmt.Errorf("write error")
				}
				return nil
			}
			if tc.runBefore {
				require.NoError(t, d.Run())
				require.True(t, d.IsMoving())
				time.Sleep(time.Millisecond)
			}
			d.disabled = false
			require.True(t, d.IsEnabled())
			// act
			err := d.Disable()
			// assert
			if tc.wantErr != "" {
				require.ErrorContains(t, err, tc.wantErr)
			} else {
				require.NoError(t, err)
				assert.Equal(t, byte(1), writtenValue) // enable pin is active low
			}
			assert.Equal(t, tc.wantEnabled, d.IsEnabled())
			assert.False(t, d.IsMoving())
			assert.Equal(t, tc.wantWrites, numCallsWrite)
			assert.Equal(t, tc.enPin, writtenPin)
		})
	}
}

func TestEasySleep_IsSleeping(t *testing.T) {
	const anglePerStep = 0.5 // use non int step angle to check int math

	tests := map[string]struct {
		sleepPin         string
		runBefore        bool
		simulateWriteErr bool
		wantWrites       int
		wantSleep        bool
		wantErr          string
	}{
		"basic": {
			sleepPin:   "10",
			wantWrites: 1,
			wantSleep:  true,
		},
		"with_run": {
			sleepPin:   "11",
			runBefore:  true,
			wantWrites: 1,
			wantSleep:  true,
		},
		"error_no_pin": {
			sleepPin:   "",
			wantSleep:  false,
			wantWrites: 0,
			wantErr:    "sleepPin is not set",
		},
		"error_write": {
			sleepPin:         "12",
			simulateWriteErr: true,
			wantWrites:       1,
			wantSleep:        false,
			wantErr:          "write error",
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			a := newGpioTestAdaptor()
			d := NewEasyDriver(a, anglePerStep, "1", WithEasySleepPin(tc.sleepPin))
			d.sleeping = false
			require.False(t, d.IsSleeping())
			// arrange: writes
			var numCallsWrite int
			var writtenPin string
			writtenValue := byte(0xFF)
			a.digitalWriteFunc = func(pin string, val byte) error {
				if pin == d.stepPin {
					// we do not consider call of step()
					return nil
				}
				numCallsWrite++
				writtenPin = pin
				writtenValue = val
				if tc.simulateWriteErr {
					return fmt.Errorf("write error")
				}
				return nil
			}
			if tc.runBefore {
				require.NoError(t, d.Run())
			}
			// act
			err := d.Sleep()
			// assert
			if tc.wantErr != "" {
				require.ErrorContains(t, err, tc.wantErr)
			} else {
				require.NoError(t, err)
				assert.Equal(t, byte(0), writtenValue) // sleep pin is active low
			}
			assert.Equal(t, tc.wantSleep, d.IsSleeping())
			assert.Equal(t, tc.wantWrites, numCallsWrite)
			assert.Equal(t, tc.sleepPin, writtenPin)
		})
	}
}

func TestEasyWake_IsSleeping(t *testing.T) {
	const anglePerStep = 0.5 // use non int step angle to check int math

	tests := map[string]struct {
		sleepPin         string
		simulateWriteErr bool
		wantWrites       int
		wantSleep        bool
		wantErr          string
	}{
		"basic": {
			sleepPin:   "10",
			wantWrites: 1,
			wantSleep:  false,
		},
		"error_no_pin": {
			sleepPin:   "",
			wantWrites: 0,
			wantSleep:  true,
			wantErr:    "sleepPin is not set",
		},
		"error_write": {
			sleepPin:         "12",
			simulateWriteErr: true,
			wantWrites:       1,
			wantSleep:        true,
			wantErr:          "write error",
		},
	}
	for name, tc := range tests {
		t.Run(name, func(t *testing.T) {
			// arrange
			a := newGpioTestAdaptor()
			d := NewEasyDriver(a, anglePerStep, "1", WithEasySleepPin(tc.sleepPin))
			d.sleeping = true
			require.True(t, d.IsSleeping())
			// arrange: writes
			var numCallsWrite int
			var writtenPin string
			writtenValue := byte(0xFF)
			a.digitalWriteFunc = func(pin string, val byte) error {
				if pin == d.stepPin {
					// we do not consider call of step()
					return nil
				}
				numCallsWrite++
				writtenPin = pin
				writtenValue = val
				if tc.simulateWriteErr {
					return fmt.Errorf("write error")
				}
				return nil
			}
			// act
			err := d.Wake()
			// assert
			if tc.wantErr != "" {
				require.ErrorContains(t, err, tc.wantErr)
			} else {
				require.NoError(t, err)
				assert.Equal(t, byte(1), writtenValue) // sleep pin is active low
			}
			assert.Equal(t, tc.wantSleep, d.IsSleeping())
			assert.Equal(t, tc.wantWrites, numCallsWrite)
			assert.Equal(t, tc.sleepPin, writtenPin)
		})
	}
}