/*
 * Copyright (C) 2019 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.systemui.statusbar

import android.animation.Animator
import android.animation.AnimatorListenerAdapter
import android.animation.ValueAnimator
import android.content.Context
import android.content.res.Configuration
import android.os.PowerManager
import android.os.SystemClock
import android.util.IndentingPrintWriter
import android.view.MotionEvent
import android.view.VelocityTracker
import android.view.ViewConfiguration
import androidx.annotation.VisibleForTesting
import com.android.app.animation.Interpolators
import com.android.systemui.Dumpable
import com.android.systemui.Gefingerpoken
import com.android.systemui.classifier.Classifier.NOTIFICATION_DRAG_DOWN
import com.android.systemui.dagger.SysUISingleton
import com.android.systemui.dump.DumpManager
import com.android.systemui.plugins.FalsingManager
import com.android.systemui.plugins.statusbar.StatusBarStateController
import com.android.systemui.res.R
import com.android.systemui.shade.domain.interactor.ShadeInteractor
import com.android.systemui.statusbar.notification.NotificationWakeUpCoordinator
import com.android.systemui.statusbar.notification.row.ExpandableNotificationRow
import com.android.systemui.statusbar.notification.row.ExpandableView
import com.android.systemui.statusbar.notification.stack.NotificationStackScrollLayoutController
import com.android.systemui.statusbar.phone.KeyguardBypassController
import com.android.systemui.statusbar.policy.ConfigurationController
import com.android.systemui.statusbar.policy.HeadsUpManager
import java.io.PrintWriter
import javax.inject.Inject
import kotlin.math.max

/**
 * A utility class that handles notification panel expansion when a user swipes downward on a
 * notification from the pulsing state.
 * If face-bypass is enabled, the user can swipe down anywhere on the screen (not just from a
 * notification) to trigger the notification panel expansion.
 */
@SysUISingleton
class PulseExpansionHandler @Inject
constructor(
    context: Context,
    private val wakeUpCoordinator: NotificationWakeUpCoordinator,
    private val bypassController: KeyguardBypassController,
    private val headsUpManager: HeadsUpManager,
    configurationController: ConfigurationController,
    private val statusBarStateController: StatusBarStateController,
    private val falsingManager: FalsingManager,
    private val shadeInteractor: ShadeInteractor,
    private val lockscreenShadeTransitionController: LockscreenShadeTransitionController,
    dumpManager: DumpManager
) : Gefingerpoken, Dumpable {
    companion object {
        private val SPRING_BACK_ANIMATION_LENGTH_MS = 375
    }

    private val mPowerManager: PowerManager?

    private var mInitialTouchX: Float = 0.0f
    private var mInitialTouchY: Float = 0.0f
    var isExpanding: Boolean = false
        private set(value) {
            val changed = field != value
            field = value
            bypassController.isPulseExpanding = value
            if (changed) {
                if (value) {
                    lockscreenShadeTransitionController.onPulseExpansionStarted()
                } else {
                    if (!leavingLockscreen) {
                        bypassController.maybePerformPendingUnlock()
                        pulseExpandAbortListener?.run()
                    }
                }
                headsUpManager.unpinAll(
                    /*userUnPinned= */
                    true,
                )
            }
        }
    var leavingLockscreen: Boolean = false
        private set
    private var touchSlop = 0f
    private var minDragDistance = 0
    private lateinit var stackScrollerController: NotificationStackScrollLayoutController
    private val mTemp2 = IntArray(2)
    private var mDraggedFarEnough: Boolean = false
    private var mStartingChild: ExpandableView? = null
    private var mPulsing: Boolean = false

    private var velocityTracker: VelocityTracker? = null

    private val isFalseTouch: Boolean
        get() = falsingManager.isFalseTouch(NOTIFICATION_DRAG_DOWN)
    var pulseExpandAbortListener: Runnable? = null
    var bouncerShowing: Boolean = false

    init {
        initResources(context)
        configurationController.addCallback(object : ConfigurationController.ConfigurationListener {
            override fun onConfigChanged(newConfig: Configuration?) {
                initResources(context)
            }
        })

        mPowerManager = context.getSystemService(PowerManager::class.java)
        dumpManager.registerDumpable(this)
    }

    private fun initResources(context: Context) {
        minDragDistance = context.resources.getDimensionPixelSize(
            R.dimen.keyguard_drag_down_min_distance)
        touchSlop = ViewConfiguration.get(context).scaledTouchSlop.toFloat()
    }

    override fun onInterceptTouchEvent(event: MotionEvent): Boolean {
        return canHandleMotionEvent() && startExpansion(event)
    }

    private fun canHandleMotionEvent(): Boolean {
        return wakeUpCoordinator.canShowPulsingHuns && !shadeInteractor.isQsExpanded.value &&
            !bouncerShowing
    }

    private fun startExpansion(event: MotionEvent): Boolean {
        if (velocityTracker == null) {
            velocityTracker = VelocityTracker.obtain()
        }
        velocityTracker!!.addMovement(event)
        val x = event.x
        val y = event.y

        when (event.actionMasked) {
            MotionEvent.ACTION_DOWN -> {
                mDraggedFarEnough = false
                isExpanding = false
                leavingLockscreen = false
                mStartingChild = null
                mInitialTouchY = y
                mInitialTouchX = x
            }

            MotionEvent.ACTION_MOVE -> {
                val h = y - mInitialTouchY
                if (h > touchSlop && h > Math.abs(x - mInitialTouchX)) {
                    isExpanding = true
                    captureStartingChild(mInitialTouchX, mInitialTouchY)
                    mInitialTouchY = y
                    mInitialTouchX = x
                    return true
                }
            }

            MotionEvent.ACTION_UP -> {
                recycleVelocityTracker()
                isExpanding = false
            }

            MotionEvent.ACTION_CANCEL -> {
                recycleVelocityTracker()
                isExpanding = false
            }
        }
        return false
    }

    private fun recycleVelocityTracker() {
        velocityTracker?.recycle()
        velocityTracker = null
    }

    override fun onTouchEvent(event: MotionEvent): Boolean {
        val finishExpanding = (event.action == MotionEvent.ACTION_CANCEL ||
            event.action == MotionEvent.ACTION_UP) && isExpanding

        val isDraggingNotificationOrCanBypass = mStartingChild?.showingPulsing() == true ||
            bypassController.canBypass()
        if ((!canHandleMotionEvent() || !isDraggingNotificationOrCanBypass) && !finishExpanding) {
            // We allow cancellations/finishing to still go through here to clean up the state
            return false
        }

        if (velocityTracker == null || !isExpanding ||
            event.actionMasked == MotionEvent.ACTION_DOWN) {
            return startExpansion(event)
        }
        velocityTracker!!.addMovement(event)
        val y = event.y

        val moveDistance = y - mInitialTouchY
        when (event.actionMasked) {
            MotionEvent.ACTION_MOVE -> updateExpansionHeight(moveDistance)
            MotionEvent.ACTION_UP -> {
                velocityTracker!!.computeCurrentVelocity(
                    /* units= */
                    1000,
                )
                val canExpand = moveDistance > 0 && velocityTracker!!.getYVelocity() > -1000 &&
                    statusBarStateController.state != StatusBarState.SHADE
                if (!falsingManager.isUnlockingDisabled && !isFalseTouch && canExpand) {
                    finishExpansion()
                } else {
                    cancelExpansion()
                }
                recycleVelocityTracker()
            }

            MotionEvent.ACTION_CANCEL -> {
                cancelExpansion()
                recycleVelocityTracker()
            }
        }
        return isExpanding
    }

    private fun finishExpansion() {
        val startingChild = mStartingChild
        if (mStartingChild != null) {
            setUserLocked(mStartingChild!!, false)
            mStartingChild = null
        }
        if (statusBarStateController.isDozing) {
            wakeUpCoordinator.willWakeUp = true
            mPowerManager!!.wakeUp(
                SystemClock.uptimeMillis(),
                PowerManager.WAKE_REASON_GESTURE,
                "com.android.systemui:PULSEDRAG"
            )
        }
        lockscreenShadeTransitionController.goToLockedShade(
            startingChild,
            needsQSAnimation = false
        )
        lockscreenShadeTransitionController.finishPulseAnimation(cancelled = false)
        leavingLockscreen = true
        isExpanding = false
        if (mStartingChild is ExpandableNotificationRow) {
            val row = mStartingChild as ExpandableNotificationRow?
            row!!.onExpandedByGesture(
                /*userExpanded= */
                true,
            )
        }
    }

    private fun updateExpansionHeight(height: Float) {
        var expansionHeight = max(height, 0.0f)
        if (mStartingChild != null) {
            val child = mStartingChild!!
            val newHeight = Math.min(
                (child.collapsedHeight + expansionHeight).toInt(),
                child.maxContentHeight
            )
            child.actualHeight = newHeight
        } else {
            wakeUpCoordinator.setNotificationsVisibleForExpansion(
                height
                    > lockscreenShadeTransitionController.distanceUntilShowingPulsingNotifications,
                /*animate= */
                true,
                /*increaseSpeed= */
                true
            )
        }
        lockscreenShadeTransitionController.setPulseHeight(expansionHeight, animate = false)
    }

    private fun captureStartingChild(x: Float, y: Float) {
        if (mStartingChild == null && !bypassController.bypassEnabled) {
            mStartingChild = findView(x, y)
            if (mStartingChild != null) {
                setUserLocked(mStartingChild!!, true)
            }
        }
    }

    @VisibleForTesting
    fun reset(
        child: ExpandableView,
        animationDuration: Long = SPRING_BACK_ANIMATION_LENGTH_MS.toLong()
    ) {
        if (child.actualHeight == child.collapsedHeight) {
            setUserLocked(child, false)
            return
        }
        val anim = ValueAnimator.ofInt(child.actualHeight, child.collapsedHeight)
        anim.interpolator = Interpolators.FAST_OUT_SLOW_IN
        anim.duration = animationDuration
        anim.addUpdateListener { animation: ValueAnimator ->
            // don't use reflection, because the `actualHeight` field may be obfuscated
            child.actualHeight = animation.animatedValue as Int
        }
        anim.addListener(object : AnimatorListenerAdapter() {
            override fun onAnimationEnd(animation: Animator) {
                setUserLocked(child, false)
            }
        })
        anim.start()
    }

    private fun setUserLocked(child: ExpandableView, userLocked: Boolean) {
        if (child is ExpandableNotificationRow) {
            child.isUserLocked = userLocked
        }
    }

    private fun cancelExpansion() {
        isExpanding = false
        if (mStartingChild != null) {
            reset(mStartingChild!!)
            mStartingChild = null
        }
        lockscreenShadeTransitionController.finishPulseAnimation(cancelled = true)
        wakeUpCoordinator.setNotificationsVisibleForExpansion(
            /*visible= */
            false,
            /*animate= */
            true,
            /*increaseSpeed= */
            false
        )
    }

    private fun findView(x: Float, y: Float): ExpandableView? {
        var totalX = x
        var totalY = y
        stackScrollerController.getLocationOnScreen(mTemp2)
        totalX += mTemp2[0].toFloat()
        totalY += mTemp2[1].toFloat()
        val childAtRawPosition = stackScrollerController.getChildAtRawPosition(totalX, totalY)
        return if (childAtRawPosition != null && childAtRawPosition.isContentExpandable) {
            childAtRawPosition
        } else {
            null
        }
    }

    fun setUp(stackScrollerController: NotificationStackScrollLayoutController) {
        this.stackScrollerController = stackScrollerController
    }

    fun setPulsing(pulsing: Boolean) {
        mPulsing = pulsing
    }

    override fun dump(pw: PrintWriter, args: Array<out String>) {
        IndentingPrintWriter(pw, "  ").let {
            it.println("PulseExpansionHandler:")
            it.increaseIndent()
            it.println("isExpanding: $isExpanding")
            it.println("leavingLockscreen: $leavingLockscreen")
            it.println("mPulsing: $mPulsing")
            it.println("bouncerShowing: $bouncerShowing")
        }
    }
}