/*

 * Geekttrss is a RSS feed reader application on the Android Platform.

 *

 *

 * This file is part of Geekttrss.

 *

 * Geekttrss 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.

 *

 * Geekttrss 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 Geekttrss.  If not, see <http://www.gnu.org/licenses/>.

 */

package com.geekorum.favikonsnoop.snoopers

import com.geekorum.favikonsnoop.FaviconInfo

import com.geekorum.favikonsnoop.Snooper

import kotlinx.coroutines.CoroutineDispatcher

import kotlinx.coroutines.Dispatchers

import kotlinx.coroutines.withContext

import okhttp3.HttpUrl

import okio.BufferedSource

import org.jsoup.Jsoup

open class LinkRelSnooper internal constructor(

    private val relValue: String,

    private val ioDispatcher: CoroutineDispatcher = Dispatchers.IO

) : Snooper() {

    override suspend fun snoop(baseUrl: HttpUrl, content: BufferedSource): Collection<FaviconInfo> = withContext(ioDispatcher) {

        val document = runCatching { Jsoup.parse(content.inputStream() , null, baseUrl.toString()) }

        document.getOrNull()?.head()?.let { head ->

            head.getElementsByTag("link")

                .filter { element ->

                    relValue in element.attr("rel").split("\\s".toRegex())

                }

                .flatMap {

                    val url = it.attr("abs:href")

                    val type = it.attr("type").ifEmpty { null }

                    val sizes = parseSizes(it.attr("sizes"))

                    if (sizes.isEmpty()) {

                        listOf(FaviconInfo(url, mimeType = type))

                    } else {

                        sizes.map { dimension ->

                            FaviconInfo(url,

                                mimeType = type,

                                dimension = dimension

                            )

                        }

                    }

                }

        } ?: emptyList()

    }

}