/*
 * Copyright (C) 2010 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 com.android.launcher3.Alarm
import com.android.launcher3.CellLayout
import com.android.launcher3.Launcher
import com.android.launcher3.OnAlarmListener
import com.android.launcher3.Utilities

class SpringLoadedDragController(private val launcher: Launcher) : OnAlarmListener {
    internal val alarm = Alarm().also { it.setOnAlarmListener(this) }

    // the screen the user is currently hovering over, if any
    private var screen: CellLayout? = null

    fun cancel() = alarm.cancelAlarm()

    // Set a new alarm to expire for the screen that we are hovering over now
    fun setAlarm(cl: CellLayout?) {
        cancel()
        alarm.setAlarm(
            when {
                cl == null -> ENTER_SPRING_LOAD_CANCEL_HOVER_TIME
                // Some TAPL tests are flaky on Cuttlefish with a low waiting time
                Utilities.isRunningInTestHarness() -> ENTER_SPRING_LOAD_HOVER_TIME_IN_TEST
                else -> ENTER_SPRING_LOAD_HOVER_TIME
            }
        )
        screen = cl
    }

    // this is called when our timer runs out
    override fun onAlarm(alarm: Alarm) {
        if (screen != null) {
            // Snap to the screen that we are hovering over now
            with(launcher.workspace) {
                if (!isVisible(screen) && launcher.dragController.mDistanceSinceScroll != 0) {
                    snapToPage(indexOfChild(screen))
                }
            }
        } else {
            launcher.dragController.cancelDrag()
        }
    }

    companion object {
        // how long the user must hover over a mini-screen before it unshrinks
        private const val ENTER_SPRING_LOAD_HOVER_TIME: Long = 500
        private const val ENTER_SPRING_LOAD_HOVER_TIME_IN_TEST: Long = 3000
        private const val ENTER_SPRING_LOAD_CANCEL_HOVER_TIME: Long = 950
    }
}