/*
 * Copyright (c) 2017-present Robert Jaros
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package pl.treksoft.kvision.remote

import com.fasterxml.jackson.databind.module.SimpleModule
import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
import com.fasterxml.jackson.module.kotlin.readValue
import io.ktor.application.ApplicationCall
import io.ktor.application.call
import io.ktor.http.cio.websocket.CloseReason
import io.ktor.http.cio.websocket.Frame
import io.ktor.http.cio.websocket.close
import io.ktor.http.cio.websocket.readText
import io.ktor.request.receive
import io.ktor.response.respond
import io.ktor.routing.Route
import io.ktor.routing.delete
import io.ktor.routing.get
import io.ktor.routing.options
import io.ktor.routing.post
import io.ktor.routing.put
import io.ktor.util.pipeline.PipelineContext
import io.ktor.websocket.WebSocketServerSession
import io.ktor.websocket.webSocket
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.channels.ClosedSendChannelException
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.SendChannel
import kotlinx.coroutines.coroutineScope
import kotlinx.coroutines.launch
import org.slf4j.Logger
import org.slf4j.LoggerFactory
import pl.treksoft.kvision.types.*
import java.math.BigDecimal
import java.time.LocalDate
import java.time.LocalDateTime
import java.time.LocalTime
import java.time.OffsetDateTime
import java.time.OffsetTime
import kotlin.reflect.KClass

/**
 * Multiplatform service manager for Ktor.
 */
@Suppress("LargeClass", "TooManyFunctions", "BlockingMethodInNonBlockingContext")
actual open class KVServiceManager<T : Any> actual constructor(val serviceClass: KClass<T>) {

    companion object {
        val LOG: Logger = LoggerFactory.getLogger(KVServiceManager::class.java.name)
    }

    val getRequests: MutableMap<String, suspend PipelineContext<Unit, ApplicationCall>.(Unit) -> Unit> = mutableMapOf()
    val postRequests: MutableMap<String, suspend PipelineContext<Unit, ApplicationCall>.(Unit) -> Unit> = mutableMapOf()
    val putRequests: MutableMap<String, suspend PipelineContext<Unit, ApplicationCall>.(Unit) -> Unit> = mutableMapOf()
    val deleteRequests: MutableMap<String, suspend PipelineContext<Unit, ApplicationCall>.(Unit) -> Unit> =
        mutableMapOf()
    val optionsRequests: MutableMap<String, suspend PipelineContext<Unit, ApplicationCall>.(Unit) -> Unit> =
        mutableMapOf()
    val webSocketRequests: MutableMap<String, suspend WebSocketServerSession.() -> Unit> =
        mutableMapOf()

    val mapper = jacksonObjectMapper().apply {
        val module = SimpleModule()
        module.addSerializer(LocalDateTime::class.java, LocalDateTimeSerializer())
        module.addSerializer(LocalDate::class.java, LocalDateSerializer())
        module.addSerializer(LocalTime::class.java, LocalTimeSerializer())
        module.addSerializer(OffsetDateTime::class.java, OffsetDateTimeSerializer())
        module.addSerializer(OffsetTime::class.java, OffsetTimeSerializer())
        module.addSerializer(BigDecimal::class.java, BigDecimalSerializer())
        module.addDeserializer(LocalDateTime::class.java, LocalDateTimeDeserializer())
        module.addDeserializer(LocalDate::class.java, LocalDateDeserializer())
        module.addDeserializer(LocalTime::class.java, LocalTimeDeserializer())
        module.addDeserializer(OffsetDateTime::class.java, OffsetDateTimeDeserializer())
        module.addDeserializer(OffsetTime::class.java, OffsetTimeDeserializer())
        module.addDeserializer(BigDecimal::class.java, BigDecimalDeserializer())
        this.registerModule(module)
    }
    var counter: Int = 0

    /**
     * Binds a given route with a function of the receiver.
     * @param function a function of the receiver
     * @param method a HTTP method
     * @param route a route
     */
    @Suppress("TooGenericExceptionCaught")
    protected actual inline fun <reified RET> bind(
        noinline function: suspend T.() -> RET,
        method: HttpMethod, route: String?
    ) {
        val routeDef = route ?: "route${this::class.simpleName}${counter++}"
        addRoute(method, "/kv/$routeDef") {
            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
            val jsonRpcRequest = if (method == HttpMethod.GET) {
                JsonRpcRequest(call.request.queryParameters["id"]?.toInt() ?: 0, "", listOf())
            } else {
                call.receive()
            }
            try {
                val result = function.invoke(service)
                call.respond(
                    JsonRpcResponse(
                        id = jsonRpcRequest.id,
                        result = mapper.writeValueAsString(result)
                    )
                )
            } catch (e: Exception) {
                if (e !is ServiceException) LOG.error(e.message, e)
                call.respond(
                    JsonRpcResponse(
                        id = jsonRpcRequest.id,
                        error = e.message ?: "Error",
                        exceptionType = e.javaClass.canonicalName
                    )
                )
            }
        }
    }

    /**
     * Binds a given route with a function of the receiver.
     * @param function a function of the receiver
     * @param method a HTTP method
     * @param route a route
     */
    @Suppress("TooGenericExceptionCaught")
    protected actual inline fun <reified PAR, reified RET> bind(
        noinline function: suspend T.(PAR) -> RET,
        method: HttpMethod, route: String?
    ) {
        if (method == HttpMethod.GET)
            throw UnsupportedOperationException("GET method is only supported for methods without parameters")
        val routeDef = route ?: "route${this::class.simpleName}${counter++}"
        addRoute(method, "/kv/$routeDef") {
            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
            val jsonRpcRequest = call.receive<JsonRpcRequest>()
            if (jsonRpcRequest.params.size == 1) {
                val param = getParameter<PAR>(jsonRpcRequest.params[0])
                try {
                    val result = function.invoke(service, param)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            result = mapper.writeValueAsString(result)
                        )
                    )
                } catch (e: Exception) {
                    if (e !is ServiceException) LOG.error(e.message, e)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            error = e.message ?: "Error",
                            exceptionType = e.javaClass.canonicalName
                        )
                    )
                }
            } else {
                call.respond(
                    JsonRpcResponse(
                        id = jsonRpcRequest.id,
                        error = "Invalid parameters"
                    )
                )
            }
        }
    }

    /**
     * Binds a given route with a function of the receiver.
     * @param function a function of the receiver
     * @param method a HTTP method
     * @param route a route
     */
    @Suppress("TooGenericExceptionCaught")
    protected actual inline fun <reified PAR1, reified PAR2, reified RET> bind(
        noinline function: suspend T.(PAR1, PAR2) -> RET,
        method: HttpMethod, route: String?
    ) {
        if (method == HttpMethod.GET)
            throw UnsupportedOperationException("GET method is only supported for methods without parameters")
        val routeDef = route ?: "route${this::class.simpleName}${counter++}"
        addRoute(method, "/kv/$routeDef") {
            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
            val jsonRpcRequest = call.receive<JsonRpcRequest>()
            if (jsonRpcRequest.params.size == 2) {
                val param1 = getParameter<PAR1>(jsonRpcRequest.params[0])
                val param2 = getParameter<PAR2>(jsonRpcRequest.params[1])
                try {
                    val result = function.invoke(service, param1, param2)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            result = mapper.writeValueAsString(result)
                        )
                    )
                } catch (e: Exception) {
                    if (e !is ServiceException) LOG.error(e.message, e)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            error = e.message ?: "Error",
                            exceptionType = e.javaClass.canonicalName
                        )
                    )
                }
            } else {
                call.respond(
                    JsonRpcResponse(
                        id = jsonRpcRequest.id,
                        error = "Invalid parameters"
                    )
                )
            }
        }
    }

    /**
     * Binds a given route with a function of the receiver.
     * @param function a function of the receiver
     * @param method a HTTP method
     * @param route a route
     */
    @Suppress("TooGenericExceptionCaught")
    protected actual inline fun <reified PAR1, reified PAR2, reified PAR3, reified RET> bind(
        noinline function: suspend T.(PAR1, PAR2, PAR3) -> RET,
        method: HttpMethod, route: String?
    ) {
        if (method == HttpMethod.GET)
            throw UnsupportedOperationException("GET method is only supported for methods without parameters")
        val routeDef = route ?: "route${this::class.simpleName}${counter++}"
        addRoute(method, "/kv/$routeDef") {
            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
            val jsonRpcRequest = call.receive<JsonRpcRequest>()
            @Suppress("MagicNumber")
            if (jsonRpcRequest.params.size == 3) {
                val param1 = getParameter<PAR1>(jsonRpcRequest.params[0])
                val param2 = getParameter<PAR2>(jsonRpcRequest.params[1])
                val param3 = getParameter<PAR3>(jsonRpcRequest.params[2])
                try {
                    val result = function.invoke(service, param1, param2, param3)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            result = mapper.writeValueAsString(result)
                        )
                    )
                } catch (e: Exception) {
                    if (e !is ServiceException) LOG.error(e.message, e)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            error = e.message ?: "Error",
                            exceptionType = e.javaClass.canonicalName
                        )
                    )
                }
            } else {
                call.respond(
                    JsonRpcResponse(
                        id = jsonRpcRequest.id,
                        error = "Invalid parameters"
                    )
                )
            }
        }
    }

    /**
     * Binds a given route with a function of the receiver.
     * @param function a function of the receiver
     * @param method a HTTP method
     * @param route a route
     */
    @Suppress("TooGenericExceptionCaught")
    protected actual inline fun <reified PAR1, reified PAR2, reified PAR3, reified PAR4, reified RET> bind(
        noinline function: suspend T.(PAR1, PAR2, PAR3, PAR4) -> RET,
        method: HttpMethod, route: String?
    ) {
        if (method == HttpMethod.GET)
            throw UnsupportedOperationException("GET method is only supported for methods without parameters")
        val routeDef = route ?: "route${this::class.simpleName}${counter++}"
        addRoute(method, "/kv/$routeDef") {
            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
            val jsonRpcRequest = call.receive<JsonRpcRequest>()
            @Suppress("MagicNumber")
            if (jsonRpcRequest.params.size == 4) {
                val param1 = getParameter<PAR1>(jsonRpcRequest.params[0])
                val param2 = getParameter<PAR2>(jsonRpcRequest.params[1])
                val param3 = getParameter<PAR3>(jsonRpcRequest.params[2])
                val param4 = getParameter<PAR4>(jsonRpcRequest.params[3])
                try {
                    val result = function.invoke(service, param1, param2, param3, param4)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            result = mapper.writeValueAsString(result)
                        )
                    )
                } catch (e: Exception) {
                    if (e !is ServiceException) LOG.error(e.message, e)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            error = e.message ?: "Error",
                            exceptionType = e.javaClass.canonicalName
                        )
                    )
                }
            } else {
                call.respond(
                    JsonRpcResponse(
                        id = jsonRpcRequest.id,
                        error = "Invalid parameters"
                    )
                )
            }
        }
    }

    /**
     * Binds a given route with a function of the receiver.
     * @param function a function of the receiver
     * @param method a HTTP method
     * @param route a route
     */
    @Suppress("TooGenericExceptionCaught")
    protected actual inline fun <reified PAR1, reified PAR2, reified PAR3,
            reified PAR4, reified PAR5, reified RET> bind(
        noinline function: suspend T.(PAR1, PAR2, PAR3, PAR4, PAR5) -> RET,
        method: HttpMethod, route: String?
    ) {
        if (method == HttpMethod.GET)
            throw UnsupportedOperationException("GET method is only supported for methods without parameters")
        val routeDef = route ?: "route${this::class.simpleName}${counter++}"
        addRoute(method, "/kv/$routeDef") {
            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
            val jsonRpcRequest = call.receive<JsonRpcRequest>()
            @Suppress("MagicNumber")
            if (jsonRpcRequest.params.size == 5) {
                val param1 = getParameter<PAR1>(jsonRpcRequest.params[0])
                val param2 = getParameter<PAR2>(jsonRpcRequest.params[1])
                val param3 = getParameter<PAR3>(jsonRpcRequest.params[2])
                val param4 = getParameter<PAR4>(jsonRpcRequest.params[3])
                val param5 = getParameter<PAR5>(jsonRpcRequest.params[4])
                try {
                    val result = function.invoke(service, param1, param2, param3, param4, param5)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            result = mapper.writeValueAsString(result)
                        )
                    )
                } catch (e: Exception) {
                    if (e !is ServiceException) LOG.error(e.message, e)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            error = e.message ?: "Error",
                            exceptionType = e.javaClass.canonicalName
                        )
                    )
                }
            } else {
                call.respond(
                    JsonRpcResponse(
                        id = jsonRpcRequest.id,
                        error = "Invalid parameters"
                    )
                )
            }
        }
    }

    /**
     * Binds a given route with a function of the receiver.
     * @param function a function of the receiver
     * @param method a HTTP method
     * @param route a route
     */
    @Suppress("TooGenericExceptionCaught")
    protected actual inline fun <reified PAR1, reified PAR2, reified PAR3,
            reified PAR4, reified PAR5, reified PAR6, reified RET> bind(
        noinline function: suspend T.(PAR1, PAR2, PAR3, PAR4, PAR5, PAR6) -> RET,
        method: HttpMethod, route: String?
    ) {
        if (method == HttpMethod.GET)
            throw UnsupportedOperationException("GET method is only supported for methods without parameters")
        val routeDef = route ?: "route${this::class.simpleName}${counter++}"
        addRoute(method, "/kv/$routeDef") {
            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
            val jsonRpcRequest = call.receive<JsonRpcRequest>()
            @Suppress("MagicNumber")
            if (jsonRpcRequest.params.size == 6) {
                val param1 = getParameter<PAR1>(jsonRpcRequest.params[0])
                val param2 = getParameter<PAR2>(jsonRpcRequest.params[1])
                val param3 = getParameter<PAR3>(jsonRpcRequest.params[2])
                val param4 = getParameter<PAR4>(jsonRpcRequest.params[3])
                val param5 = getParameter<PAR5>(jsonRpcRequest.params[4])
                val param6 = getParameter<PAR6>(jsonRpcRequest.params[5])
                try {
                    val result = function.invoke(service, param1, param2, param3, param4, param5, param6)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            result = mapper.writeValueAsString(result)
                        )
                    )
                } catch (e: Exception) {
                    if (e !is ServiceException) LOG.error(e.message, e)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            error = e.message ?: "Error",
                            exceptionType = e.javaClass.canonicalName
                        )
                    )
                }
            } else {
                call.respond(
                    JsonRpcResponse(
                        id = jsonRpcRequest.id,
                        error = "Invalid parameters"
                    )
                )
            }
        }
    }

    /**
     * Binds a given web socket connetion with a function of the receiver.
     * @param function a function of the receiver
     * @param route a route
     */
    @OptIn(ExperimentalCoroutinesApi::class)
    @Suppress("EmptyCatchBlock")
    protected actual inline fun <reified PAR1 : Any, reified PAR2 : Any> bind(
        noinline function: suspend T.(ReceiveChannel<PAR1>, SendChannel<PAR2>) -> Unit,
        route: String?
    ) {
        val routeDef = route ?: "route${this::class.simpleName}${counter++}"
        webSocketRequests["/kvws/$routeDef"] = {
            val wsInjector = call.injector.createChildInjector(WsSessionModule(this))
            val service = wsInjector.getInstance(serviceClass.java)
            val requestChannel = Channel<PAR1>()
            val responseChannel = Channel<PAR2>()
            val session = this
            coroutineScope {
                launch {
                    for (p in incoming) {
                        (p as? Frame.Text)?.readText()?.let { text ->
                            val jsonRpcRequest = getParameter<JsonRpcRequest>(text)
                            if (jsonRpcRequest.params.size == 1) {
                                val par = getParameter<PAR1>(jsonRpcRequest.params[0])
                                requestChannel.send(par)
                            }
                        }
                    }
                    requestChannel.close()
                }
                launch {
                    for (p in responseChannel) {
                        val text = mapper.writeValueAsString(
                            JsonRpcResponse(
                                id = 0,
                                result = mapper.writeValueAsString(p)
                            )
                        )
                        outgoing.send(Frame.Text(text))
                    }
                    try {
                        session.close(CloseReason(CloseReason.Codes.NORMAL, ""))
                    } catch (e: ClosedSendChannelException) {
                    }
                    session.close()
                }
                launch {
                    function.invoke(service, requestChannel, responseChannel)
                    if (!responseChannel.isClosedForReceive) responseChannel.close()
                }
            }
        }
    }

    /**
     * Binds a given function of the receiver as a tabulator component source
     * @param function a function of the receiver
     */
    @Suppress("TooGenericExceptionCaught")
    protected actual inline fun <reified RET> bindTabulatorRemote(
        noinline function: suspend T.(Int?, Int?, List<RemoteFilter>?, List<RemoteSorter>?, String?) -> RemoteData<RET>,
        route: String?
    ) {
        val routeDef = route ?: "route${this::class.simpleName}${counter++}"
        addRoute(HttpMethod.POST, "/kv/$routeDef") {
            val service = call.injector.createChildInjector(DummyWsSessionModule()).getInstance(serviceClass.java)
            val jsonRpcRequest = call.receive<JsonRpcRequest>()
            @Suppress("MagicNumber")
            if (jsonRpcRequest.params.size == 5) {
                val param1 = getParameter<Int?>(jsonRpcRequest.params[0])
                val param2 = getParameter<Int?>(jsonRpcRequest.params[1])
                val param3 = getParameter<List<RemoteFilter>?>(jsonRpcRequest.params[2])

                @Suppress("MagicNumber")
                val param4 = getParameter<List<RemoteSorter>?>(jsonRpcRequest.params[3])

                @Suppress("MagicNumber")
                val param5 = getParameter<String?>(jsonRpcRequest.params[4])
                try {
                    val result = function.invoke(service, param1, param2, param3, param4, param5)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            result = mapper.writeValueAsString(result)
                        )
                    )
                } catch (e: Exception) {
                    if (e !is ServiceException) LOG.error(e.message, e)
                    call.respond(
                        JsonRpcResponse(
                            id = jsonRpcRequest.id,
                            error = e.message ?: "Error",
                            exceptionType = e.javaClass.canonicalName
                        )
                    )
                }
            } else {
                call.respond(
                    JsonRpcResponse(
                        id = jsonRpcRequest.id,
                        error = "Invalid parameters"
                    )
                )
            }
        }
    }

    /**
     * @suppress Internal method
     */
    fun addRoute(
        method: HttpMethod,
        path: String,
        handler: suspend PipelineContext<Unit, ApplicationCall>.(Unit) -> Unit
    ) {
        when (method) {
            HttpMethod.GET -> getRequests[path] = handler
            HttpMethod.POST -> postRequests[path] = handler
            HttpMethod.PUT -> putRequests[path] = handler
            HttpMethod.DELETE -> deleteRequests[path] = handler
            HttpMethod.OPTIONS -> optionsRequests[path] = handler
        }
    }

    /**
     * @suppress Internal method
     */
    protected inline fun <reified T> getParameter(str: String?): T {
        return str?.let {
            if (T::class == String::class) {
                str as T
            } else {
                mapper.readValue(str)
            }
        } ?: null as T
    }
}

/**
 * A function to generate routes based on definitions from the service manager.
 */
fun <T : Any> Route.applyRoutes(serviceManager: KVServiceManager<T>) {
    serviceManager.getRequests.forEach { (path, handler) ->
        get(path, handler)
    }
    serviceManager.postRequests.forEach { (path, handler) ->
        post(path, handler)
    }
    serviceManager.putRequests.forEach { (path, handler) ->
        put(path, handler)
    }
    serviceManager.deleteRequests.forEach { (path, handler) ->
        delete(path, handler)
    }
    serviceManager.optionsRequests.forEach { (path, handler) ->
        options(path, handler)
    }
    serviceManager.webSocketRequests.forEach { (path, handler) ->
        this.webSocket(path) {
            handler()
        }
    }
}