/*
 * Copyright (C) 2025 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 com.android.launcher3.dragndrop

import android.net.Uri
import android.platform.test.annotations.EnableFlags
import android.platform.test.flag.junit.SetFlagsRule
import android.view.DragEvent
import androidx.test.filters.SmallTest
import com.android.launcher3.Flags.FLAG_ENABLE_SYSTEM_DRAG
import com.android.launcher3.Launcher
import com.android.launcher3.dagger.LauncherAppComponent
import com.android.launcher3.dagger.LauncherAppSingleton
import com.android.launcher3.util.AllModulesForTest
import com.android.launcher3.util.LauncherMultivalentJUnit
import com.android.launcher3.util.SandboxApplication
import dagger.BindsInstance
import dagger.Component
import org.junit.Assert.assertFalse
import org.junit.Assert.assertTrue
import org.junit.Before
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith
import org.mockito.ArgumentCaptor
import org.mockito.Mock
import org.mockito.Mockito.verify
import org.mockito.junit.MockitoJUnit
import org.mockito.kotlin.clearInvocations
import org.mockito.kotlin.mock
import org.mockito.kotlin.times
import org.mockito.kotlin.verifyNoInteractions
import org.mockito.kotlin.verifyNoMoreInteractions
import org.mockito.kotlin.whenever

/** Tests for {@link SystemDragControllerImpl}. */
@SmallTest
@EnableFlags(FLAG_ENABLE_SYSTEM_DRAG)
@RunWith(LauncherMultivalentJUnit::class)
class SystemDragControllerImplTest {

    @get:Rule val context = SandboxApplication()
    @get:Rule val flags = SetFlagsRule()
    @get:Rule val mockito = MockitoJUnit.rule()

    @Mock private lateinit var mockDragEvent: DragEvent
    @Mock private lateinit var mockItemInfo: SystemDragItemInfo
    @Mock private lateinit var mockLauncher: Launcher
    @Mock private lateinit var mockSystemDragListener: SystemDragListener
    @Mock private lateinit var mockUri: Uri

    private lateinit var controller: SystemDragControllerImpl

    @Before
    fun setUp() {
        initMock(mockLauncher)
        initMock(mockSystemDragListener)

        context.initDaggerComponent(
            DaggerSystemDragControllerImplTest_TestComponent.builder()
                .bindSystemDragListenerFactory { mockSystemDragListener }
        )

        val controller = SystemDragController.INSTANCE[context]
        assertTrue(controller is SystemDragControllerImpl)
        this.controller = controller as SystemDragControllerImpl
    }

    @Test
    fun testAcceptDropWhenUriListIsEmpty() {
        whenever(mockItemInfo.uriList).thenReturn(emptyList())
        assertFalse(controller.acceptDrop(mockItemInfo))
    }

    @Test
    fun testAcceptDropWhenUriListIsNull() {
        whenever(mockItemInfo.uriList).thenReturn(null)
        assertFalse(controller.acceptDrop(mockItemInfo))
    }

    @Test
    fun testAcceptDropWhenUriListIsPopulated() {
        whenever(mockItemInfo.uriList).thenReturn(listOf(mockUri))
        assertTrue(controller.acceptDrop(mockItemInfo))
    }

    @Test
    fun testDragContinue() {
        testDragStart()
        clearInvocations(mockSystemDragListener)

        whenever(mockDragEvent.action).thenReturn(DragEvent.ACTION_DRAG_LOCATION)
        whenever(mockLauncher.dragController.isDragging).thenReturn(true)

        // NOTE: Fulfillment is delegated to the system drag listener.
        assertTrue(controller.onDrag(mockDragEvent))
        verify(mockSystemDragListener).onDrag(mockDragEvent)

        whenever(mockLauncher.dragController.isDragging).thenReturn(false)

        // NOTE: Fulfillment is delegated to the system drag listener.
        assertTrue(controller.onDrag(mockDragEvent))
        verify(mockSystemDragListener, times(2)).onDrag(mockDragEvent)
    }

    @Test
    fun testDragStart() {
        controller.setLauncher(mockLauncher)

        whenever(mockDragEvent.action).thenReturn(DragEvent.ACTION_DRAG_STARTED)
        whenever(mockLauncher.dragController.isDragging).thenReturn(false)

        // NOTE: Fulfillment is delegated to the system drag listener.
        assertTrue(controller.onDrag(mockDragEvent))
        verify(mockSystemDragListener).onDrag(mockDragEvent)
    }

    @Test
    fun testDragStartAfterCleanup() {
        testDragStart()

        val cleanupCallbackCaptor = ArgumentCaptor.forClass(Runnable::class.java)
        verify(mockSystemDragListener).setCleanupCallback(cleanupCallbackCaptor.capture())
        cleanupCallbackCaptor.value.run()

        val oldMockSystemDragListener = mockSystemDragListener
        mockSystemDragListener = mock<SystemDragListener>().apply(this::initMock)

        testDragStart()
        verifyNoMoreInteractions(oldMockSystemDragListener)
    }

    @Test
    fun testDragStartWhenActionIsNotStarted() {
        controller.setLauncher(mockLauncher)

        whenever(mockDragEvent.action).thenReturn(DragEvent.ACTION_DRAG_LOCATION)
        whenever(mockLauncher.dragController.isDragging).thenReturn(false)

        // NOTE: Fulfillment is *not* delegated to the system drag listener.
        assertFalse(controller.onDrag(mockDragEvent))
        verifyNoInteractions(mockSystemDragListener)
    }

    @Test
    fun testDragStartWhenAlreadyDragging() {
        controller.setLauncher(mockLauncher)

        whenever(mockDragEvent.action).thenReturn(DragEvent.ACTION_DRAG_STARTED)
        whenever(mockLauncher.dragController.isDragging).thenReturn(true)

        // NOTE: Fulfillment is *not* delegated to the system drag listener.
        assertFalse(controller.onDrag(mockDragEvent))
        verifyNoInteractions(mockSystemDragListener)
    }

    @Test
    fun testSetLauncher() {
        controller.setLauncher(mockLauncher)
        verify(mockLauncher.dragController).addSystemDragHandler(controller)

        val oldMockLauncher = mockLauncher
        mockLauncher = mock<Launcher>().apply(this::initMock)

        controller.setLauncher(mockLauncher)
        verify(oldMockLauncher.dragController).removeSystemDragHandler(controller)
        verify(mockLauncher.dragController).addSystemDragHandler(controller)
    }

    private fun initMock(mockLauncher: Launcher) {
        whenever(mockLauncher.dragController).thenReturn(mock())
    }

    private fun initMock(mockSystemDragListener: SystemDragListener) {
        whenever(mockSystemDragListener.onDrag(mockDragEvent)).thenReturn(true)
    }

    @LauncherAppSingleton
    @Component(modules = [AllModulesForTest::class])
    interface TestComponent : LauncherAppComponent {
        @Component.Builder
        interface Builder : LauncherAppComponent.Builder {
            @BindsInstance
            fun bindSystemDragListenerFactory(factory: SystemDragListenerFactory): Builder

            override fun build(): TestComponent
        }
    }
}