Backend: Start/stop logic, events and initial API surface

web/backend/src/main/kotlin/dev/kordex/extra/web/Route.kt

@@ -0,0 +1,51 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+package dev.kordex.extra.web
+
+import io.ktor.http.*
+import io.ktor.server.application.*
+import io.ktor.server.response.*
+
+@Suppress("StringLiteralDuplication")
+public abstract class Route(public val extension: String) {
+	public abstract val path: String
+
+	public open suspend fun delete(call: ApplicationCall) {
+		call.response.header("Content-Type", "application/json")
+		call.respond(HttpStatusCode.MethodNotAllowed, mutableMapOf("error" to "Method not allowed"))
+	}
+
+	public open suspend fun get(call: ApplicationCall) {
+		call.response.header("Content-Type", "application/json")
+		call.respond(HttpStatusCode.MethodNotAllowed, mutableMapOf("error" to "Method not allowed"))
+	}
+
+	public open suspend fun head(call: ApplicationCall) {
+		call.response.header("Content-Type", "application/json")
+		call.respond(HttpStatusCode.MethodNotAllowed, mutableMapOf("error" to "Method not allowed"))
+	}
+
+	public open suspend fun options(call: ApplicationCall) {
+		call.response.header("Content-Type", "application/json")
+		call.respond(HttpStatusCode.MethodNotAllowed, mutableMapOf("error" to "Method not allowed"))
+	}
+
+	public open suspend fun patch(call: ApplicationCall) {
+		call.response.header("Content-Type", "application/json")
+		call.respond(HttpStatusCode.MethodNotAllowed, mutableMapOf("error" to "Method not allowed"))
+	}
+
+	public open suspend fun post(call: ApplicationCall) {
+		call.response.header("Content-Type", "application/json")
+		call.respond(HttpStatusCode.MethodNotAllowed, mutableMapOf("error" to "Method not allowed"))
+	}
+
+	public open suspend fun put(call: ApplicationCall) {
+		call.response.header("Content-Type", "application/json")
+		call.respond(HttpStatusCode.MethodNotAllowed, mutableMapOf("error" to "Method not allowed"))
+	}
+}

web/backend/src/main/kotlin/dev/kordex/extra/web/WebExtension.kt

@@ -7,11 +7,23 @@
 package dev.kordex.extra.web
 
 import com.kotlindiscord.kord.extensions.extensions.Extension
+import dev.kordex.extra.web.config.WebServerConfig
+import dev.kordex.extra.web.server.WebServer
 
-public class WebExtension : Extension() {
+public class WebExtension(private val config: WebServerConfig) : Extension() {
 	override val name: String = "kordex-web"
 
+	public lateinit var server: WebServer
+
 	override suspend fun setup() {
-		TODO("Not yet implemented")
+		server = WebServer(config)
+
+		server.start()
+	}
+
+	override suspend fun unload() {
+		if (this::server.isInitialized) {
+			server.stop()
+		}
 	}
 }

web/backend/src/main/kotlin/dev/kordex/extra/web/events/WebServerStartEvent.kt

@@ -0,0 +1,12 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+package dev.kordex.extra.web.events
+
+import com.kotlindiscord.kord.extensions.events.KordExEvent
+import dev.kordex.extra.web.server.WebServer
+
+public class WebServerStartEvent(public val server: WebServer) : KordExEvent

web/backend/src/main/kotlin/dev/kordex/extra/web/events/WebServerStopEvent.kt

@@ -0,0 +1,11 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+package dev.kordex.extra.web.events
+
+import com.kotlindiscord.kord.extensions.events.KordExEvent
+
+public class WebServerStopEvent : KordExEvent

web/backend/src/main/kotlin/dev/kordex/extra/web/routes/RouteRegistry.kt

@@ -0,0 +1,70 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+package dev.kordex.extra.web.routes
+
+import com.kotlindiscord.kord.extensions.events.ExtensionStateEvent
+import com.kotlindiscord.kord.extensions.extensions.ExtensionState
+import com.kotlindiscord.kord.extensions.koin.KordExKoinComponent
+import dev.kordex.extra.web.Route
+import io.ktor.http.*
+import io.ktor.server.application.*
+import io.ktor.server.response.*
+import io.ktor.util.pipeline.*
+
+public class RouteRegistry : KordExKoinComponent {
+	private val routes: MutableMap<String, Route> = mutableMapOf()
+
+	public suspend fun handle(verb: Verb, context: PipelineContext<Unit, ApplicationCall>) {
+		val call = context.call
+
+		val path = call.parameters.getAll("path")
+			?.joinToString("/")
+
+		val route = routes[path]
+			?: return call.respond(HttpStatusCode.NotFound)
+
+		when (verb) {
+			Verb.DELETE -> route.delete(call)
+			Verb.GET -> route.get(call)
+			Verb.HEAD -> route.head(call)
+			Verb.OPTIONS -> route.options(call)
+			Verb.PATCH -> route.patch(call)
+			Verb.POST -> route.post(call)
+			Verb.PUT -> route.put(call)
+		}
+	}
+
+	public fun handleExtensionState(event: ExtensionStateEvent) {
+		if (event.state == ExtensionState.UNLOADING) {
+			val toRemove = routes.filter { it.value.extension == event.extension.name }
+
+			toRemove.forEach { routes.remove(it.key) }
+		}
+	}
+
+	public fun add(route: Route): Boolean {
+		val path = "${route.extension}/${route.path}"
+
+		if (path in routes) {
+			return false
+		}
+
+		routes[path] = route
+
+		return true
+	}
+
+	public fun remove(route: Route): Route? {
+		val path = "${route.extension}/${route.path}"
+
+		return routes.remove(path)
+	}
+
+	public fun removeAll() {
+		routes.clear()
+	}
+}

web/backend/src/main/kotlin/dev/kordex/extra/web/routes/Verb.kt

@@ -0,0 +1,19 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+package dev.kordex.extra.web.routes
+
+import io.ktor.http.*
+
+public sealed class Verb(public val method: HttpMethod) {
+	public data object DELETE : Verb(HttpMethod.Delete)
+	public data object GET : Verb(HttpMethod.Get)
+	public data object HEAD : Verb(HttpMethod.Head)
+	public data object OPTIONS : Verb(HttpMethod.Options)
+	public data object PATCH : Verb(HttpMethod.Patch)
+	public data object POST : Verb(HttpMethod.Post)
+	public data object PUT : Verb(HttpMethod.Put)
+}

web/backend/src/main/kotlin/dev/kordex/extra/web/server/WebServer.kt

@@ -6,10 +6,18 @@
 
 package dev.kordex.extra.web.server
 
+import com.kotlindiscord.kord.extensions.ExtensibleBot
+import com.kotlindiscord.kord.extensions.koin.KordExKoinComponent
 import dev.kordex.extra.web.config.ForwardedHeaderMode
 import dev.kordex.extra.web.config.ForwardedHeaderStrategy
 import dev.kordex.extra.web.config.WebServerConfig
+import dev.kordex.extra.web.events.WebServerStartEvent
+import dev.kordex.extra.web.events.WebServerStopEvent
+import dev.kordex.extra.web.routes.RouteRegistry
+import dev.kordex.extra.web.routes.Verb
+import dev.kordex.extra.web.websockets.WebsocketRegistry
 import io.ktor.http.*
+import io.ktor.serialization.kotlinx.*
 import io.ktor.serialization.kotlinx.json.*
 import io.ktor.serialization.kotlinx.xml.*
 import io.ktor.server.application.*
@@ -23,11 +31,21 @@ import io.ktor.server.plugins.statuspages.*
 import io.ktor.server.response.*
 import io.ktor.server.routing.*
 import io.ktor.server.websocket.*
+import kotlinx.serialization.json.Json
+import org.koin.core.component.inject
 import kotlin.time.Duration.Companion.seconds
 
 private val CORS_SCHEMES = listOf("http", "https", "ws", "wss")
 
-public class WebServer(private val config: WebServerConfig) {
+public class WebServer(private val config: WebServerConfig) : KordExKoinComponent {
+	private val bot: ExtensibleBot by inject()
+
+	public val routeRegistry: RouteRegistry = RouteRegistry()
+	public val wsRegistry: WebsocketRegistry = WebsocketRegistry()
+
+	public var running: Boolean = false
+		private set
+
 	private val server = embeddedServer(Netty, port = config.port) {
 		install(ContentNegotiation) {
 			json()
@@ -47,10 +65,13 @@ public class WebServer(private val config: WebServerConfig) {
 
 			allowHeader(HttpHeaders.ContentType)
 
+			allowMethod(HttpMethod.Delete)
+			allowMethod(HttpMethod.Get)
+			allowMethod(HttpMethod.Head)
 			allowMethod(HttpMethod.Options)
-			allowMethod(HttpMethod.Put)
 			allowMethod(HttpMethod.Patch)
-			allowMethod(HttpMethod.Delete)
+			allowMethod(HttpMethod.Post)
+			allowMethod(HttpMethod.Put)
 		}
 
 		when (config.forwardedHeaderMode) {
@@ -93,6 +114,8 @@ public class WebServer(private val config: WebServerConfig) {
 			// For some reason, ktor uses Java durations instead of Kotlin ones for the easy properties?
 			pingPeriodMillis = 15.seconds.inWholeMilliseconds
 			timeoutMillis = 15.seconds.inWholeMilliseconds
+
+			contentConverter = KotlinxWebsocketSerializationConverter(Json.Default)
 		}
 
 		routing {
@@ -103,15 +126,26 @@ public class WebServer(private val config: WebServerConfig) {
 		}
 	}
 
-	public fun start() {
+	public suspend fun start() {
 		server.start(wait = false)
+
+		running = true
+
+		bot.send(WebServerStartEvent(this))
 	}
 
-	public fun stop() {
+	public suspend fun stop() {
+		routeRegistry.removeAll()
+		wsRegistry.removeAll()
+
 		server.stop(
 			gracePeriodMillis = 0,
 			timeoutMillis = 0
 		)
+
+		running = false
+
+		bot.send(WebServerStopEvent())
 	}
 
 	private fun Routing.setup() {
@@ -126,6 +160,42 @@ public class WebServer(private val config: WebServerConfig) {
 			}
 		}
 
+		route("/api/extensions/{path...}") {
+			delete {
+				routeRegistry.handle(Verb.DELETE, this)
+			}
+
+			get {
+				routeRegistry.handle(Verb.GET, this)
+			}
+
+			head {
+				routeRegistry.handle(Verb.HEAD, this)
+			}
+
+			options {
+				routeRegistry.handle(Verb.OPTIONS, this)
+			}
+
+			patch {
+				routeRegistry.handle(Verb.PATCH, this)
+			}
+
+			post {
+				routeRegistry.handle(Verb.POST, this)
+			}
+
+			put {
+				routeRegistry.handle(Verb.PUT, this)
+			}
+		}
+
+		route("/ws/extensions/{path...}") {
+			webSocket {
+				wsRegistry.handle(this)
+			}
+		}
+
 		// TODO: Other routes
 	}
 }

web/backend/src/main/kotlin/dev/kordex/extra/web/utils/_Builder.kt

@@ -0,0 +1,19 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+package dev.kordex.extra.web.utils
+
+import com.kotlindiscord.kord.extensions.builders.ExtensibleBotBuilder
+import dev.kordex.extra.web.WebExtension
+import dev.kordex.extra.web.config.WebServerConfig
+
+public fun ExtensibleBotBuilder.ExtensionsBuilder.web(builder: WebServerConfig.() -> Unit) {
+	val config = WebServerConfig()
+
+	builder(config)
+
+	add { WebExtension(config) }
+}

web/backend/src/main/kotlin/dev/kordex/extra/web/utils/_Extension.kt

@@ -0,0 +1,27 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+package dev.kordex.extra.web.utils
+
+import com.kotlindiscord.kord.extensions.events.EventContext
+import dev.kordex.extra.web.Route
+import dev.kordex.extra.web.events.WebServerStartEvent
+import dev.kordex.extra.web.websockets.WebsocketBuilder
+import dev.kordex.extra.web.websockets.WebsocketBuilderFun
+
+public fun EventContext<WebServerStartEvent>.route(route: Route) {
+	if (!event.server.routeRegistry.add(route)) {
+		error("Route at ${route.path} for extension ${eventHandler.extension.name} already exists.")
+	}
+}
+
+public fun EventContext<WebServerStartEvent>.websocket(path: String, body: WebsocketBuilderFun) {
+	val socketBuilder = WebsocketBuilder(eventHandler.extension.name, body)
+
+	if (!event.server.wsRegistry.add(path, socketBuilder)) {
+		error("Websocket at $path for extension ${eventHandler.extension.name} already exists.")
+	}
+}