/*
Mangadex@Home
Copyright (c) 2020, MangaDex Network
This file is part of MangaDex@Home.

MangaDex@Home 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.

MangaDex@Home 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 MangaDex@Home.  If not, see <http://www.gnu.org/licenses/>.
*/
package mdnet

import com.fasterxml.jackson.databind.DeserializationFeature
import com.fasterxml.jackson.module.kotlin.KotlinModule
import mdnet.ServerHandlerJackson.auto
import mdnet.logging.info
import mdnet.settings.DevSettings
import mdnet.settings.RemoteSettings
import mdnet.settings.ServerSettings
import org.apache.hc.client5.http.impl.DefaultSchemePortResolver
import org.apache.hc.client5.http.impl.classic.HttpClients
import org.apache.hc.client5.http.impl.routing.DefaultRoutePlanner
import org.apache.hc.core5.http.HttpHost
import org.apache.hc.core5.http.protocol.HttpContext
import org.http4k.client.ApacheClient
import org.http4k.core.Body
import org.http4k.core.Method
import org.http4k.core.Request
import org.http4k.format.ConfigurableJackson
import org.http4k.format.asConfigurable
import org.http4k.format.withStandardMappings
import org.slf4j.LoggerFactory
import java.net.InetAddress

object ServerHandlerJackson : ConfigurableJackson(
    KotlinModule()
        .asConfigurable()
        .withStandardMappings()
        .done()
        .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
)

class BackendApi(
    private val serverSettings: ServerSettings,
    private val devSettings: DevSettings,
    private val maxCacheSizeInMebibytes: Long
) {
    private val client = ApacheClient(
        client = HttpClients.custom()
            .setRoutePlanner(
                object : DefaultRoutePlanner(DefaultSchemePortResolver()) {
                    override fun determineLocalAddress(firstHop: HttpHost?, context: HttpContext?): InetAddress {
                        return InetAddress.getByName(serverSettings.hostname)
                    }
                }
            )
            .build()
    )

    fun logoutFromControl(): Boolean {
        LOGGER.info { "Disconnecting from the control server" }
        val params = mapOf<String, Any>(
            "secret" to serverSettings.secret
        )

        val request = STRING_ANY_MAP_LENS(params, Request(Method.POST, getServerAddress() + "stop"))
        val response = client(request)

        return response.status.successful
    }

    private fun getPingParams(tlsCreatedAt: String? = null): Map<String, Any> =
        mapOf(
            "secret" to serverSettings.secret,
            "port" to let {
                if (serverSettings.externalPort != 0) {
                    serverSettings.externalPort
                } else {
                    serverSettings.port
                }
            },
            "disk_space" to maxCacheSizeInMebibytes * 1024 * 1024,
            "network_speed" to serverSettings.externalMaxKilobitsPerSecond * 1000 / 8,
            "build_version" to Constants.CLIENT_BUILD
        ).let {
            if (tlsCreatedAt != null) {
                it.plus("tls_created_at" to tlsCreatedAt)
            } else {
                it
            }
        }

    fun loginToControl(): RemoteSettings? {
        LOGGER.info { "Connecting to the control server" }

        val request = STRING_ANY_MAP_LENS(getPingParams(), Request(Method.POST, getServerAddress() + "ping"))
        val response = client(request)

        return if (response.status.successful) {
            SERVER_SETTINGS_LENS(response)
        } else {
            null
        }
    }

    fun pingControl(old: RemoteSettings): RemoteSettings? {
        LOGGER.info { "Pinging the control server" }

        val request = STRING_ANY_MAP_LENS(
            getPingParams(old.tls!!.createdAt),
            Request(
                Method.POST,
                getServerAddress() + "ping"
            )
        )
        val response = client(request)

        return if (response.status.successful) {
            SERVER_SETTINGS_LENS(response)
        } else {
            null
        }
    }

    private fun getServerAddress(): String {
        return devSettings.devUrl ?: SERVER_ADDRESS
    }

    companion object {
        private val LOGGER = LoggerFactory.getLogger(BackendApi::class.java)
        private val STRING_ANY_MAP_LENS = Body.auto<Map<String, Any>>().toLens()
        private val SERVER_SETTINGS_LENS = Body.auto<RemoteSettings>().toLens()
        private const val SERVER_ADDRESS = "https://api.mangadex.network/"
    }
}