/*
 * 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.web

import android.webkit.WebResourceRequest
import android.webkit.WebResourceResponse
import android.webkit.WebView
import com.pitchedapps.frost.utils.FrostPglAdBlock
import com.pitchedapps.frost.utils.L
import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
import java.io.ByteArrayInputStream

/**
 * Created by Allan Wang on 2017-07-13.
 *
 * Handler to decide when a request should be done by us
 * This is the crux of Frost's optimizations for the web browser
 */
private val blankResource: WebResourceResponse =
    WebResourceResponse(
        "text/plain",
        "utf-8",
        ByteArrayInputStream("".toByteArray())
    )

fun WebView.shouldFrostInterceptRequest(request: WebResourceRequest): WebResourceResponse? {
    val requestUrl = request.url?.toString() ?: return null
    val httpUrl = requestUrl.toHttpUrlOrNull() ?: return null
    val host = httpUrl.host
    val url = httpUrl.toString()
    if (host.contains("facebook") || host.contains("fbcdn")) return null
    if (FrostPglAdBlock.isAd(host)) return blankResource
//    if (!shouldLoadImages && !Prefs.loadMediaOnMeteredNetwork && request.isMedia) return blankResource
    L.v { "Intercept Request: $host $url" }
    return null
}

/**
 * Wrapper to ensure that null exceptions are not reached
 */
fun WebResourceRequest.query(action: (url: String) -> Boolean): Boolean {
    return action(url?.path ?: return false)
}

val WebResourceRequest.isImage: Boolean
    get() = query { it.contains(".jpg") || it.contains(".png") }

val WebResourceRequest.isMedia: Boolean
    get() = query { it.contains(".jpg") || it.contains(".png") || it.contains("video") }

/**
 * Generic filter passthrough
 * If Resource is already nonnull, pass it, otherwise check if filter is met and override the response accordingly
 */
fun WebResourceResponse?.filter(request: WebResourceRequest, filter: (url: String) -> Boolean) =
    filter(request.query { filter(it) })

fun WebResourceResponse?.filter(filter: Boolean): WebResourceResponse? = this
    ?: if (filter) blankResource else null

fun WebResourceResponse?.filterCss(request: WebResourceRequest): WebResourceResponse? =
    filter(request) { it.endsWith(".css") }

fun WebResourceResponse?.filterImage(request: WebResourceRequest): WebResourceResponse? =
    filter(request.isImage)