package com.gh.common.view

import android.content.Context
import android.os.Build
import android.util.AttributeSet
import android.view.MotionEvent
import android.widget.LinearLayout
import androidx.annotation.Nullable
import androidx.core.view.children
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleObserver
import androidx.lifecycle.OnLifecycleEvent
import androidx.recyclerview.widget.RecyclerView
import java.lang.ref.WeakReference
import java.util.*

class AutoScrollRecyclerViewContainerView(context: Context, @Nullable attrs: AttributeSet?)
    : LinearLayout(context, attrs), LifecycleObserver {

    var autoScrollTask: AutoScrollTask?

    private var mIsScrolling = false
    private var mIsScrollable = false

    private var mOnItemTouchListener: RecyclerView.OnItemTouchListener? = null

    init {
        autoScrollTask = AutoScrollTask(this)
    }

    override fun onAttachedToWindow() {
        super.onAttachedToWindow()

        if (mOnItemTouchListener == null) {
            mOnItemTouchListener = object : RecyclerView.OnItemTouchListener {
                override fun onTouchEvent(rv: RecyclerView, e: MotionEvent) {}
                override fun onInterceptTouchEvent(rv: RecyclerView, e: MotionEvent) = rv.scrollState == RecyclerView.SCROLL_STATE_DRAGGING
                override fun onRequestDisallowInterceptTouchEvent(disallowIntercept: Boolean) {}
            }
        }

        for (child in children) {
            if (child is RecyclerView) {
                child.removeOnItemTouchListener(mOnItemTouchListener!!)
                child.addOnItemTouchListener(mOnItemTouchListener!!)
            }
        }

        resumeScrolling()
    }

    override fun onDetachedFromWindow() {
        super.onDetachedFromWindow()

        pauseScrolling()
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    fun resumeScrolling() {
        if (mIsScrolling) return

        if (mIsScrolling) pauseScrolling()
        mIsScrollable = true
        mIsScrolling = true
        postDelayed(autoScrollTask, AUTO_SCROLL_INTERVAL)
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
    fun pauseScrolling() {
        mIsScrolling = false
        removeCallbacks(autoScrollTask)
    }

    fun setLifeCycleOwner(lifeCycleOwner: Lifecycle) {
        lifeCycleOwner.addObserver(this)
    }

    companion object {
        private const val AUTO_SCROLL_INTERVAL: Long = 10
    }

    class AutoScrollTask(reference: AutoScrollRecyclerViewContainerView?) : Runnable {
        private val mReference: WeakReference<AutoScrollRecyclerViewContainerView?>?
        private val mScrollSlop = if (Build.MODEL.toLowerCase(Locale.getDefault()) == "mumu") 1 else 2

        init {
            mReference = WeakReference(reference)
        }

        override fun run() {
            val containerView: AutoScrollRecyclerViewContainerView? = mReference?.get()
            if (containerView != null && containerView.mIsScrolling && containerView.mIsScrollable) {
                for (child in containerView.children) {
                    if (child is RecyclerView) {
                        child.scrollBy(mScrollSlop, mScrollSlop)
                    }
                }
                containerView.postDelayed(containerView.autoScrollTask, AUTO_SCROLL_INTERVAL)
            }
        }
    }
}