mangadex_at_home/src/main/kotlin/mdnet/base/ServerHandler.kt

/*
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.base

import com.fasterxml.jackson.databind.DeserializationFeature
import com.fasterxml.jackson.module.kotlin.KotlinModule
import java.net.InetAddress
import mdnet.base.ServerHandlerJackson.auto
import mdnet.base.settings.DevSettings
import mdnet.base.settings.RemoteSettings
import mdnet.base.settings.ServerSettings
import org.apache.http.client.config.RequestConfig
import org.apache.http.impl.client.HttpClients
import org.http4k.client.Apache4Client
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

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

class ServerHandler(private val serverSettings: ServerSettings, private val devSettings: DevSettings, private val maxCacheSizeInMebibytes: Long) {
    private val client = Apache4Client(client = HttpClients.custom()
        .setDefaultRequestConfig(
            RequestConfig.custom()
                .apply {
                    if (serverSettings.clientHostname != "0.0.0.0") {
                        setLocalAddress(InetAddress.getByName(serverSettings.clientHostname))
                    }
                }
                .build())
        .build())

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

        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<String, Any>(
            "secret" to serverSettings.clientSecret,
            "port" to let {
                if (serverSettings.clientExternalPort != 0) {
                    serverSettings.clientExternalPort
                } else {
                    serverSettings.clientPort
                }
            },
            "disk_space" to maxCacheSizeInMebibytes * 1024 * 1024,
            "network_speed" to serverSettings.maxKilobitsPerSecond * 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 if (!devSettings.isDev)
            SERVER_ADDRESS
        else
            SERVER_ADDRESS_DEV
    }

    companion object {
        private val LOGGER = LoggerFactory.getLogger(ServerHandler::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 = "http://fakemdnet/"
        private const val SERVER_ADDRESS_DEV = "https://mangadex-test.net/"
    }
}