path: root/app/src/main/kotlin/com/pitchedapps/frost/views/FrostWebView.kt

/*
 * Copyright 2018 Allan Wang
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.pitchedapps.frost.views

import android.animation.ValueAnimator
import android.annotation.SuppressLint
import android.app.Activity
import android.content.Context
import android.graphics.Color
import android.util.AttributeSet
import android.view.View
import android.view.ViewGroup
import ca.allanwang.kau.utils.AnimHolder
import ca.allanwang.kau.utils.ctxCoroutine
import ca.allanwang.kau.utils.launchMain
import com.pitchedapps.frost.contracts.FrostContentContainer
import com.pitchedapps.frost.contracts.FrostContentCore
import com.pitchedapps.frost.contracts.FrostContentParent
import com.pitchedapps.frost.contracts.WebFileChooser
import com.pitchedapps.frost.db.CookieDao
import com.pitchedapps.frost.db.currentCookie
import com.pitchedapps.frost.facebook.FB_HOME_URL
import com.pitchedapps.frost.facebook.FbCookie
import com.pitchedapps.frost.facebook.USER_AGENT
import com.pitchedapps.frost.fragments.WebFragment
import com.pitchedapps.frost.injectors.ThemeProvider
import com.pitchedapps.frost.prefs.Prefs
import com.pitchedapps.frost.utils.L
import com.pitchedapps.frost.utils.frostDownload
import com.pitchedapps.frost.web.FrostChromeClient
import com.pitchedapps.frost.web.FrostJSI
import com.pitchedapps.frost.web.FrostWebViewClient
import com.pitchedapps.frost.web.NestedWebView
import dagger.BindsInstance
import dagger.hilt.DefineComponent
import dagger.hilt.EntryPoint
import dagger.hilt.EntryPoints
import dagger.hilt.InstallIn
import dagger.hilt.android.AndroidEntryPoint
import dagger.hilt.android.components.ViewComponent
import javax.inject.Inject
import javax.inject.Scope
import kotlin.math.abs
import kotlin.math.max
import kotlin.math.min

/**
 * Created by Allan Wang on 2017-05-29.
 *
 */
@AndroidEntryPoint
class FrostWebView @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0
) : NestedWebView(context, attrs, defStyleAttr), FrostContentCore {

    @Inject
    lateinit var activity: Activity

    @Inject
    lateinit var fbCookie: FbCookie

    @Inject
    lateinit var prefs: Prefs

    @Inject
    lateinit var themeProvider: ThemeProvider

    @Inject
    lateinit var webFileChooser: WebFileChooser

    @Inject
    lateinit var cookieDao: CookieDao

    @Inject
    lateinit var frostWebComponentBuilder: FrostWebComponentBuilder

    override fun reload(animate: Boolean) {
        if (parent.registerTransition(false, animate))
            super.reload()
    }

    override lateinit var parent: FrostContentParent

    internal lateinit var frostWebClient: FrostWebViewClient

    override val currentUrl: String
        get() = url ?: ""

    @SuppressLint("SetJavaScriptEnabled")
    override fun bind(container: FrostContentContainer): View {
        val component = frostWebComponentBuilder.frostWebView(this).build()
        val entryPoint = EntryPoints.get(component, FrostWebEntryPoint::class.java)
        userAgentString = USER_AGENT
        with(settings) {
            javaScriptEnabled = true
            mediaPlaybackRequiresUserGesture = false // TODO check if we need this
            allowFileAccess = true
            textZoom = prefs.webTextScaling
            domStorageEnabled = true
        }
        setLayerType(LAYER_TYPE_HARDWARE, null)
        // attempt to get custom client; otherwise fallback to original
        frostWebClient = (container as? WebFragment)?.client(this) ?: FrostWebViewClient(this)
        webViewClient = frostWebClient
        webChromeClient = FrostChromeClient(this, themeProvider, webFileChooser)
        addJavascriptInterface(entryPoint.frostJsi(), "Frost")
        setBackgroundColor(Color.TRANSPARENT)
        setDownloadListener { url, userAgent, contentDisposition, mimetype, contentLength ->
            context.ctxCoroutine.launchMain {
                val cookie = cookieDao.currentCookie(prefs) ?: return@launchMain
                context.frostDownload(
                    cookie.cookie,
                    url,
                    userAgent,
                    contentDisposition,
                    mimetype,
                    contentLength
                )
            }
        }
        return this
    }

    /**
     * Wrapper to the main userAgentString to cache it.
     * This decouples it from the UiThread
     *
     * Note that this defaults to null, but the main purpose is to
     * check if we've set our own agent.
     *
     * A null value may be interpreted as the default value
     */
    var userAgentString: String? = null
        set(value) {
            field = value
            settings.userAgentString = value
        }

    init {
        isNestedScrollingEnabled = true
    }

    fun loadUrl(url: String?, animate: Boolean) {
        if (url == null) return
        if (parent.registerTransition(this.url != url, animate))
            super.loadUrl(url)
    }

    override fun reloadBase(animate: Boolean) {
        loadUrl(parent.baseUrl, animate)
    }

    /**
     * 2018-10-17. facebook automatically adds their home page to the back stack,
     * regardless of the loaded url. We will make sure we skip it when going back.
     *
     * 2019-10-14. Looks like facebook now randomly populates some links with the home page,
     * especially those that are launched with a blank target...
     * In some cases, there can be more than one home target in a row.
     */
    override fun onBackPressed(): Boolean {
        val list = copyBackForwardList()
        if (list.currentIndex >= 2) {
            val skipCount = (1..list.currentIndex).firstOrNull {
                list.getItemAtIndex(list.currentIndex - it).url != FB_HOME_URL
            } ?: return false // If no non home url is found, we will treat the stack as empty
            L.v { "onBackPress: going back ${if (skipCount == 1) "one page" else "$skipCount pages"}" }
            goBackOrForward(-skipCount)
            return true
        }
        if (list.currentIndex == 1 && list.getItemAtIndex(0).url == FB_HOME_URL) {
            return false
        }
        if (list.currentIndex > 0) {
            goBack()
            return true
        }
        return false
    }

    /**
     * If webview is already at the top, refresh
     * Otherwise scroll to top
     */
    override fun onTabClicked() {
        if (scrollY < 5) reloadBase(true)
        else scrollToTop()
    }

    private fun scrollToTop() {
        flingScroll(0, 0) // stop fling
        if (scrollY > 10000)
            scrollTo(0, 0)
        else
            smoothScrollTo(0)
    }

    private fun smoothScrollTo(y: Int) {
        ValueAnimator.ofInt(scrollY, y).apply {
            duration = min(abs(scrollY - y), 500).toLong()
            interpolator = AnimHolder.fastOutSlowInInterpolator(context)
            addUpdateListener { scrollY = it.animatedValue as Int }
            start()
        }
    }

    private fun smoothScrollBy(y: Int) = smoothScrollTo(max(0, scrollY + y))

    override var active: Boolean = true
        set(value) {
            if (field == value) return
            field = value
            if (field) onResume()
            else onPause()
        }

    override fun reloadTheme() {
        reloadThemeSelf()
    }

    override fun reloadThemeSelf() {
        reload(false) // todo see if there's a better solution
    }

    override fun reloadTextSize() {
        reloadTextSizeSelf()
    }

    override fun reloadTextSizeSelf() {
        settings.textZoom = prefs.webTextScaling
    }

    override fun destroy() {
        (getParent() as? ViewGroup)?.removeView(this)
        super.destroy()
    }
}

@Scope
@Retention(AnnotationRetention.BINARY)
@Target(
    AnnotationTarget.FUNCTION,
    AnnotationTarget.TYPE,
    AnnotationTarget.CLASS
)
annotation class FrostWebScoped

@FrostWebScoped
@DefineComponent(parent = ViewComponent::class)
interface FrostWebComponent

@DefineComponent.Builder
interface FrostWebComponentBuilder {
    fun frostWebView(@BindsInstance web: FrostWebView): FrostWebComponentBuilder
    fun build(): FrostWebComponent
}

@EntryPoint
@InstallIn(FrostWebComponent::class)
interface FrostWebEntryPoint {
    @FrostWebScoped
    fun frostJsi(): FrostJSI
}