/*
 * 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.facebook.parsers

import com.pitchedapps.frost.db.CookieEntity
import com.pitchedapps.frost.facebook.FB_EPOCH_MATCHER
import com.pitchedapps.frost.facebook.FB_NOTIF_ID_MATCHER
import com.pitchedapps.frost.facebook.FbItem
import com.pitchedapps.frost.facebook.formattedFbUrl
import com.pitchedapps.frost.facebook.get
import com.pitchedapps.frost.services.NotificationContent
import org.jsoup.nodes.Document
import org.jsoup.nodes.Element

/**
 * Created by Allan Wang on 2017-12-25.
 *
 */
object NotifParser : FrostParser<FrostNotifs> by NotifParserImpl()

data class FrostNotifs(
    val notifs: List<FrostNotif>,
    val seeMore: FrostLink?
) : ParseNotification {

    override val isEmpty: Boolean
        get() = notifs.isEmpty()

    override fun toString() = StringBuilder().apply {
        append("FrostNotifs {\n")
        append(notifs.toJsonString("notifs", 1))
        append("\tsee more: $seeMore\n")
        append("}")
    }.toString()

    override fun getUnreadNotifications(data: CookieEntity) =
        notifs.asSequence().filter(FrostNotif::unread).map {
            with(it) {
                NotificationContent(
                    data = data,
                    id = id,
                    href = url,
                    title = null,
                    text = content,
                    timestamp = time,
                    profileUrl = img,
                    unread = unread
                )
            }
        }.toList()
}

/**
 * [id] notif id, or current time fallback
 * [img] parsed url for profile img
 * [time] time of message
 * [url] link to thread
 * [unread] true if image is unread, false otherwise
 * [content] optional string for thread
 * [timeString] text version of time from Facebook
 * [thumbnailUrl] optional thumbnail url if existent
 */
data class FrostNotif(
    val id: Long,
    val img: String?,
    val time: Long,
    val url: String,
    val unread: Boolean,
    val content: String,
    val timeString: String,
    val thumbnailUrl: String?
)

private class NotifParserImpl : FrostParserBase<FrostNotifs>(false) {

    override var nameRes = FbItem.NOTIFICATIONS.titleId

    override val url = FbItem.NOTIFICATIONS.url

    override fun parseImpl(doc: Document): FrostNotifs? {
        val notificationList = doc.getElementById("notifications_list") ?: return null
        val notifications = notificationList
            .getElementsByAttributeValueMatching("id", ".*${FB_NOTIF_ID_MATCHER.pattern}.*")
            .mapNotNull(this::parseNotif)
        val seeMore =
            parseLink(doc.getElementsByAttributeValue("href", "/notifications.php?more").first())
        return FrostNotifs(notifications, seeMore)
    }

    private fun parseNotif(element: Element): FrostNotif? {
        val a = element.getElementsByTag("a").first() ?: return null
        a.selectFirst("span.accessible_elem")?.remove()
        val abbr = element.getElementsByTag("abbr")
        val epoch = FB_EPOCH_MATCHER.find(abbr.attr("data-store"))[1]?.toLongOrNull() ?: -1L
        // fetch id
        val id = FB_NOTIF_ID_MATCHER.find(element.id())[1]?.toLongOrNull()
            ?: System.currentTimeMillis() % FALLBACK_TIME_MOD
        val img = element.getInnerImgStyle()
        val timeString = abbr.text()
        val content =
            a.text().replace("\u00a0", " ").removeSuffix(timeString).trim() // remove &nbsp;
        val thumbnail = element.selectFirst("img.thumbnail")?.attr("src")
        return FrostNotif(
            id = id,
            img = img,
            time = epoch,
            url = a.attr("href").formattedFbUrl,
            unread = !element.hasClass("acw"),
            content = content,
            timeString = timeString,
            thumbnailUrl = if (thumbnail?.isNotEmpty() == true) thumbnail else null
        )
    }
}