/*
 * Copyright 2020 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package androidx.compose.animation

import androidx.compose.animation.core.AnimationVector
import androidx.compose.animation.core.FastOutLinearInEasing
import androidx.compose.animation.core.FastOutSlowInEasing
import androidx.compose.animation.core.FloatSpringSpec
import androidx.compose.animation.core.LinearEasing
import androidx.compose.animation.core.LinearOutSlowInEasing
import androidx.compose.animation.core.TweenSpec
import androidx.compose.foundation.Box
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.setValue
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.lerp
import androidx.compose.ui.unit.Bounds
import androidx.compose.ui.unit.Position
import androidx.compose.ui.unit.PxBounds
import androidx.compose.ui.unit.dp
import androidx.compose.ui.util.lerp
import androidx.test.filters.MediumTest
import androidx.ui.test.createComposeRule
import androidx.ui.test.runOnIdle
import androidx.ui.test.waitForIdle
import org.junit.Assert.assertEquals
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith
import org.junit.runners.JUnit4

@RunWith(JUnit4::class)
@MediumTest
class SingleValueAnimationTest {

    @get:Rule
    val composeTestRule = createComposeRule()

    @Test
    fun animate1DTest() {
        val startVal = 20f
        val endVal = 250f

        var floatValue = startVal
        var dpValue = startVal.dp
        var pxValue = startVal

        fun <T> tween(): TweenSpec<T> =
            TweenSpec(
                easing = FastOutSlowInEasing,
                durationMillis = 100
            )

        val children: @Composable() (Boolean) -> Unit = { enabled ->
            floatValue = animate(
                if (enabled) endVal else startVal,
                tween()
            )

            dpValue = animate(
                if (enabled) endVal.dp else startVal.dp,
                tween()
            )

            pxValue = animate(
                if (enabled) endVal else startVal,
                tween()
            )
        }

        val verify: () -> Unit = {
            for (i in 0..100 step 50) {
                val value = lerp(
                    startVal.toFloat(), endVal.toFloat(),
                    FastOutSlowInEasing.invoke(i / 100f)
                )
                assertEquals(value, floatValue)
                assertEquals(value.dp, dpValue)
                assertEquals(value, pxValue)
                composeTestRule.clockTestRule.advanceClock(50)
                waitForIdle()
            }
        }

        animateTest(children, verify)
    }

    @Test
    fun animate2DTest() {

        val startVal = AnimationVector(120f, 56f)
        val endVal = AnimationVector(0f, 77f)

        var vectorValue = startVal
        var positionValue = Position.VectorConverter.convertFromVector(startVal)
        var sizeValue = Size.VectorConverter.convertFromVector(startVal)
        var pxPositionValue = Offset.VectorConverter.convertFromVector(startVal)

        fun <V> tween(): TweenSpec<V> =
            TweenSpec(
                easing = LinearEasing,
                durationMillis = 100
            )

        val children: @Composable() (Boolean) -> Unit = { enabled ->
            vectorValue = animate(
                if (enabled) endVal else startVal,
                tween()
            )

            positionValue = animate(
                if (enabled)
                    Position.VectorConverter.convertFromVector(endVal)
                else
                    Position.VectorConverter.convertFromVector(startVal),
                tween()
            )

            sizeValue = animate(
                if (enabled)
                    Size.VectorConverter.convertFromVector(endVal)
                else
                    Size.VectorConverter.convertFromVector(startVal),
                tween()
            )

            pxPositionValue = animate(
                if (enabled)
                    Offset.VectorConverter.convertFromVector(endVal)
                else
                    Offset.VectorConverter.convertFromVector(startVal),
                tween()
            )
        }

        val verify: () -> Unit = {
            for (i in 0..100 step 50) {
                val expect = AnimationVector(
                    lerp(startVal.v1, endVal.v1, i / 100f),
                    lerp(startVal.v2, endVal.v2, i / 100f)
                )

                assertEquals(expect, vectorValue)
                assertEquals(Size.VectorConverter.convertFromVector(expect), sizeValue)
                assertEquals(Position.VectorConverter.convertFromVector(expect), positionValue)
                assertEquals(Offset.VectorConverter.convertFromVector(expect), pxPositionValue)
                composeTestRule.clockTestRule.advanceClock(50)
                waitForIdle()
            }
        }

        animateTest(children, verify)
    }

    @Test
    fun animate4DTest() {
        val startVal = AnimationVector(30f, -76f, 280f, 35f)
        val endVal = AnimationVector(-42f, 89f, 77f, 100f)

        var vectorValue = startVal
        var boundsValue = Bounds.VectorConverter.convertFromVector(startVal)
        var pxBoundsValue = PxBounds.VectorConverter.convertFromVector(startVal)

        fun <V> tween(): TweenSpec<V> =
            TweenSpec(
                easing = LinearOutSlowInEasing,
                durationMillis = 100
            )

        val children: @Composable() (Boolean) -> Unit = { enabled ->
            vectorValue = animate(
                if (enabled) endVal else startVal,
                tween()
            )

            boundsValue = animate(
                if (enabled)
                    Bounds.VectorConverter.convertFromVector(endVal)
                else
                    Bounds.VectorConverter.convertFromVector(startVal),
                tween()
            )

            pxBoundsValue = animate(
                if (enabled)
                    PxBounds.VectorConverter.convertFromVector(endVal)
                else
                    PxBounds.VectorConverter.convertFromVector(startVal),
                tween()
            )
        }

        val verify: () -> Unit = {
            for (i in 0..100 step 50) {
                val fraction = LinearOutSlowInEasing.invoke(i / 100f)
                val expect = AnimationVector(
                    lerp(startVal.v1, endVal.v1, fraction),
                    lerp(startVal.v2, endVal.v2, fraction),
                    lerp(startVal.v3, endVal.v3, fraction),
                    lerp(startVal.v4, endVal.v4, fraction)
                )

                assertEquals(expect, vectorValue)
                assertEquals(Bounds.VectorConverter.convertFromVector(expect), boundsValue)
                assertEquals(PxBounds.VectorConverter.convertFromVector(expect), pxBoundsValue)
                composeTestRule.clockTestRule.advanceClock(50)
                waitForIdle()
            }
        }

        animateTest(children, verify)
    }

    @Test
    fun animateColorTest() {
        var value = Color.Black
        val children: @Composable() (Boolean) -> Unit = { enabled ->
            value = animate(
                if (enabled) Color.Cyan else Color.Black, TweenSpec(
                    durationMillis = 100,
                    easing = FastOutLinearInEasing
                )
            )
        }

        val verify: () -> Unit = {

            for (i in 0..100 step 50) {
                val fraction = FastOutLinearInEasing.invoke(i / 100f)
                val expected = lerp(Color.Black, Color.Cyan, fraction)
                assertEquals(expected, value)
                composeTestRule.clockTestRule.advanceClock(50)
                waitForIdle()
            }
        }

        animateTest(children, verify)
    }

    @Test
    fun visibilityThresholdTest() {

        var floatValue = 0f
        var vectorValue = AnimationVector(0f)
        var offsetValue = Offset(0f, 0f)
        var boundsValue = Bounds(0.dp, 0.dp, 0.dp, 0.dp)

        val specForFloat = FloatSpringSpec(visibilityThreshold = 0.01f)
        val specForVector = FloatSpringSpec(visibilityThreshold = PxVisibilityThreshold)
        val specForOffset = FloatSpringSpec(visibilityThreshold = PxVisibilityThreshold)
        val specForBounds = FloatSpringSpec(visibilityThreshold = DpVisibilityThreshold)

        val children: @Composable() (Boolean) -> Unit = { enabled ->
            floatValue = animate(if (enabled) 100f else 0f)

            vectorValue = animate(
                if (enabled) AnimationVector(100f) else AnimationVector(0f),
                visibilityThreshold = AnimationVector(PxVisibilityThreshold)
            )

            offsetValue = animate(
                if (enabled)
                    Offset(100f, 100f)
                else
                    Offset(0f, 0f)
            )

            boundsValue = animate(
                if (enabled)
                    Bounds(100.dp, 100.dp, 100.dp, 100.dp)
                else
                    Bounds(0.dp, 0.dp, 0.dp, 0.dp)
            )
        }

        val durationForFloat = specForFloat.getDurationMillis(0f, 100f, 0f)
        val durationForVector = specForVector.getDurationMillis(0f, 100f, 0f)
        val durationForOffset = specForOffset.getDurationMillis(0f, 100f, 0f)
        val durationForBounds = specForBounds.getDurationMillis(0f, 100f, 0f)
        val verify: () -> Unit = {
            for (i in 0..durationForFloat step 50) {
                val expectFloat = specForFloat.getValue(i, 0f, 100f, 0f)
                assertEquals("play time: $i", expectFloat, floatValue)

                if (i < durationForVector) {
                    val expectVector = specForVector.getValue(i, 0f, 100f, 0f)
                    assertEquals(AnimationVector(expectVector), vectorValue)
                } else {
                    assertEquals(AnimationVector(100f), vectorValue)
                }

                if (i < durationForOffset) {
                    val expectOffset = specForOffset.getValue(i, 0f, 100f, 0f)
                    assertEquals(Offset(expectOffset, expectOffset), offsetValue)
                } else {
                    assertEquals(Offset(100f, 100f), offsetValue)
                }

                if (i < durationForBounds) {
                    val expectBounds = specForBounds.getValue(i, 0f, 100f, 0f)
                    assertEquals(
                        Bounds(expectBounds.dp, expectBounds.dp, expectBounds.dp, expectBounds.dp),
                        boundsValue
                    )
                } else {
                    assertEquals(Bounds(100.dp, 100.dp, 100.dp, 100.dp), boundsValue)
                }

                composeTestRule.clockTestRule.advanceClock(50)
                waitForIdle()
            }
        }

        animateTest(children, verify)
    }

    private fun animateTest(children: @Composable() (Boolean) -> Unit, verify: () -> Unit) {

        composeTestRule.clockTestRule.pauseClock()
        var enabled by mutableStateOf(false)
        composeTestRule.setContent {
            Box {
                children(enabled)
            }
        }
        runOnIdle { enabled = true }
        waitForIdle()

        verify()
    }
}