package com.pitchedapps.frost.views

import android.annotation.SuppressLint
import android.content.Context
import android.graphics.Bitmap
import android.support.v4.view.MotionEventCompat
import android.support.v4.view.NestedScrollingChild
import android.support.v4.view.NestedScrollingChildHelper
import android.support.v4.view.ViewCompat
import android.util.AttributeSet
import android.view.MotionEvent
import android.view.View
import android.webkit.WebResourceError
import android.webkit.WebResourceRequest
import android.webkit.WebView
import android.webkit.WebViewClient
import com.pitchedapps.frost.utils.L
import io.reactivex.subjects.BehaviorSubject
import io.reactivex.subjects.Subject

enum class WebStatus {
    LOADING, LOADED, ERROR
}

/**
 * Created by Allan Wang on 2017-05-29.
 *
 * Courtesy of takahirom
 *
 * https://github.com/takahirom/webview-in-coordinatorlayout/blob/master/app/src/main/java/com/github/takahirom/webview_in_coodinator_layout/NestedWebView.java
 */
class FrostWebView @JvmOverloads constructor(
        context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : WebView(context, attrs, defStyleAttr), NestedScrollingChild {

    private val childHelper = NestedScrollingChildHelper(this)
    private var lastY: Int = 0
    private val scrollOffset = IntArray(2)
    private val scrollConsumed = IntArray(2)
    private var nestedOffsetY: Int = 0
    val observable: Subject<WebStatus>

    init {
        isNestedScrollingEnabled = true
        observable = BehaviorSubject.create<WebStatus>()
        setupWebview()
    }

    @SuppressLint("SetJavaScriptEnabled")
    fun setupWebview() {
        settings.javaScriptEnabled = true
        setLayerType(View.LAYER_TYPE_HARDWARE, null)
        setWebViewClient(object : WebViewClient() {
            override fun onReceivedError(view: WebView?, request: WebResourceRequest?, error: WebResourceError?) {
                super.onReceivedError(view, request, error)
                observable.onNext(WebStatus.ERROR)
                L.e("Error ${request}")
            }

            override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
                super.onPageStarted(view, url, favicon)
                observable.onNext(WebStatus.LOADING)
            }

            override fun onPageFinished(view: WebView?, url: String?) {
                super.onPageFinished(view, url)
                observable.onNext(WebStatus.LOADED)
//                CookieManager.getInstance().flush()
            }
        })
    }

    override fun onTouchEvent(ev: MotionEvent): Boolean {
        val event = MotionEvent.obtain(ev)
        val action = MotionEventCompat.getActionMasked(event)
        if (action == MotionEvent.ACTION_DOWN)
            nestedOffsetY = 0
        val eventY = event.y.toInt()
        event.offsetLocation(0f, nestedOffsetY.toFloat())
        val returnValue: Boolean
        when (action) {
            MotionEvent.ACTION_MOVE -> {
                var deltaY = lastY - eventY
                // NestedPreScroll
                if (dispatchNestedPreScroll(0, deltaY, scrollConsumed, scrollOffset)) {
                    deltaY -= scrollConsumed[1]
                    event.offsetLocation(0f, -scrollOffset[1].toFloat())
                    nestedOffsetY += scrollOffset[1]
                }
                lastY = eventY - scrollOffset[1]
                returnValue = super.onTouchEvent(event)
                // NestedScroll
                if (dispatchNestedScroll(0, scrollOffset[1], 0, deltaY, scrollOffset)) {
                    event.offsetLocation(0f, scrollOffset[1].toFloat())
                    nestedOffsetY += scrollOffset[1]
                    lastY -= scrollOffset[1]
                }
            }
            MotionEvent.ACTION_DOWN -> {
                returnValue = super.onTouchEvent(event)
                lastY = eventY
                startNestedScroll(ViewCompat.SCROLL_AXIS_VERTICAL)
            }
            MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL -> {
                returnValue = super.onTouchEvent(event)
                stopNestedScroll()
            }
            else -> return false
        }
        return returnValue
    }

    // Nested Scroll implements
    override fun setNestedScrollingEnabled(enabled: Boolean) {
        childHelper.isNestedScrollingEnabled = enabled
    }

    override fun isNestedScrollingEnabled() = childHelper.isNestedScrollingEnabled

    override fun startNestedScroll(axes: Int) = childHelper.startNestedScroll(axes)

    override fun stopNestedScroll() = childHelper.stopNestedScroll()

    override fun hasNestedScrollingParent() = childHelper.hasNestedScrollingParent()

    override fun dispatchNestedScroll(dxConsumed: Int, dyConsumed: Int, dxUnconsumed: Int, dyUnconsumed: Int, offsetInWindow: IntArray?)
            = childHelper.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, offsetInWindow)

    override fun dispatchNestedPreScroll(dx: Int, dy: Int, consumed: IntArray?, offsetInWindow: IntArray?)
            = childHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow)

    override fun dispatchNestedFling(velocityX: Float, velocityY: Float, consumed: Boolean)
            = childHelper.dispatchNestedFling(velocityX, velocityY, consumed)

    override fun dispatchNestedPreFling(velocityX: Float, velocityY: Float)
            = childHelper.dispatchNestedPreFling(velocityX, velocityY)

}