Ktor Server Core

import io.ktor.server.application.*
import io.ktor.server.engine.*
import io.ktor.server.request.*
import io.ktor.server.response.*
import io.ktor.server.routing.*

import io.ktor.server.application.*
import io.ktor.server.engine.*
import io.ktor.server.response.*
import io.ktor.server.routing.*
import io.ktor.http.*

// Create and start an embedded server (requires engine implementation)
fun main() {
    embeddedServer(SomeEngine, port = 8080) {
        routing {
            get("/") {
                call.respondText("Hello, Ktor!")
            }
            get("/users/{id}") {
                val id = call.parameters["id"]
                call.respondText("User ID: $id")
            }
        }
    }.start(wait = true)
}

// Configure application with plugins
fun Application.module() {
    install(CallLogging)
    
    routing {
        route("/api") {
            get("/health") {
                call.respond(mapOf("status" to "healthy"))
            }
        }
    }
}

interface Application {
    val environment: ApplicationEnvironment
    val monitor: Events
    val parentCoroutineContext: CoroutineContext
    suspend fun disposeAndJoin()
}

interface ApplicationCall : CoroutineScope {
    val attributes: Attributes
    val request: ApplicationRequest
    val response: ApplicationResponse
    val application: Application
    val parameters: Parameters
    suspend fun <T> receiveNullable(typeInfo: TypeInfo): T?
    suspend fun respond(message: Any?, typeInfo: TypeInfo?)
}

fun serverConfig(block: ServerConfigBuilder.() -> Unit): ServerConfig

interface ApplicationConfig {
    fun property(path: String): ApplicationConfigValue
    fun propertyOrNull(path: String): ApplicationConfigValue?
    fun config(path: String): ApplicationConfig
    fun configList(path: String): List<ApplicationConfig>
    fun keys(): Set<String>
    fun toMap(): Map<String, Any?>
}

interface ApplicationConfigValue {
    val type: Type
    fun getString(): String
    fun getList(): List<String>
    fun getAs(type: TypeInfo): Any?
}

object ConfigLoader {
    fun load(path: String? = null): ApplicationConfig
}

interface ApplicationEngine {
    val environment: ApplicationEnvironment
    suspend fun resolvedConnectors(): List<EngineConnectorConfig>
    fun start(wait: Boolean = false): ApplicationEngine
    suspend fun startSuspend(wait: Boolean = false): ApplicationEngine
    fun stop(gracePeriodMillis: Long, timeoutMillis: Long)
}

fun <TEngine : ApplicationEngine, TConfiguration : ApplicationEngine.Configuration> 
embeddedServer(
    factory: ApplicationEngineFactory<TEngine, TConfiguration>,
    port: Int = 80,
    host: String = "0.0.0.0",
    watchPaths: List<String> = emptyList(),
    configure: TConfiguration.() -> Unit = {},
    module: Application.() -> Unit
): EmbeddedServer<TEngine, TConfiguration>

interface ApplicationRequest {
    val call: ApplicationCall
    val pipeline: ApplicationReceivePipeline
    val queryParameters: Parameters
    val headers: Headers
    val local: RequestConnectionPoint
    val cookies: RequestCookies
}

interface ApplicationResponse {
    val call: ApplicationCall
    val pipeline: ApplicationSendPipeline
    val headers: ResponseHeaders
    val cookies: ResponseCookies
    fun status(): HttpStatusCode?
    fun status(value: HttpStatusCode)
}

// Extension functions for common operations
suspend inline fun <reified T> ApplicationCall.receive(): T
suspend fun ApplicationCall.receiveText(): String
suspend fun ApplicationCall.respond(message: Any)
suspend fun ApplicationCall.respondText(text: String, contentType: ContentType? = null, status: HttpStatusCode? = null)

interface Route {
    val parent: Route?
    val selector: RouteSelector
    val developmentMode: Boolean
    val environment: ApplicationEnvironment
}

interface RoutingBuilder {
    fun route(path: String, build: Route.() -> Unit): Route
    fun method(method: HttpMethod, body: Route.() -> Unit): Route
    fun handle(body: suspend PipelineContext<Unit, PipelineCall>.() -> Unit)
}

// DSL functions
fun Application.routing(configuration: Routing.() -> Unit)
fun Route.get(path: String = "", body: suspend PipelineContext<Unit, PipelineCall>.() -> Unit): Route
fun Route.post(path: String = "", body: suspend PipelineContext<Unit, PipelineCall>.() -> Unit): Route
fun Route.put(path: String = "", body: suspend PipelineContext<Unit, PipelineCall>.() -> Unit): Route
fun Route.delete(path: String = "", body: suspend PipelineContext<Unit, PipelineCall>.() -> Unit): Route

// HTTP utilities
data class Link(
    val uri: String,
    val rel: List<String>,
    val type: ContentType? = null,
    val title: String? = null
)

// Extension properties for requests
val ApplicationRequest.uri: String
val ApplicationRequest.httpMethod: HttpMethod
val ApplicationRequest.path: String
val ApplicationRequest.host: String
val ApplicationRequest.port: Int
val ApplicationRequest.contentType: ContentType
val ApplicationRequest.userAgent: String?

// Logging and MDC support
interface MDCProvider {
    fun get(key: String): String?
    fun put(key: String, value: String?)
    fun remove(key: String)
    fun clear()
}

interface Plugin<TPipeline, TConfiguration, TPlugin> {
    val key: AttributeKey<TPlugin>
    fun install(pipeline: TPipeline, configure: TConfiguration.() -> Unit = {}): TPlugin
}

interface ApplicationPlugin<TConfiguration> : BaseApplicationPlugin<Application, TConfiguration, PluginInstance>

interface RouteScopedPlugin<TConfiguration> : Plugin<RoutingNode, TConfiguration, PluginInstance>

fun createApplicationPlugin(
    name: String,
    body: PluginBuilder<Unit>.() -> Unit
): ApplicationPlugin<Unit>

fun <PluginConfigT> createApplicationPlugin(
    name: String,
    createConfiguration: () -> PluginConfigT,
    body: PluginBuilder<PluginConfigT>.() -> Unit
): ApplicationPlugin<PluginConfigT>

fun createRouteScopedPlugin(
    name: String,
    body: RouteScopedPluginBuilder<Unit>.() -> Unit
): RouteScopedPlugin<Unit>

// Install plugins into application or routes
fun <TConfiguration> Application.install(
    plugin: ApplicationPlugin<TConfiguration>,
    configure: TConfiguration.() -> Unit = {}
): PluginInstance

fun <TConfiguration> Route.install(
    plugin: RouteScopedPlugin<TConfiguration>,
    configure: TConfiguration.() -> Unit = {}
): PluginInstance

// Access installed plugins
fun <TConfiguration> Application.plugin(plugin: ApplicationPlugin<TConfiguration>): PluginInstance
fun <TConfiguration> Application.pluginOrNull(plugin: ApplicationPlugin<TConfiguration>): PluginInstance?

// Application environment and configuration
interface ApplicationEnvironment {
    val log: Logger
    val config: ApplicationConfig
}

// Request/Response connection information
interface RequestConnectionPoint {
    val scheme: String
    val version: String
    val port: Int
    val host: String
    val uri: String
    val method: HttpMethod
    val remoteHost: String
    val userAgent: String?
}

// Parameter collections
typealias Parameters = StringValues

// Pipeline phases and contexts
interface PipelineContext<TSubject, TContext>
interface PipelineInterceptor<TSubject, TContext>

// Hook system for plugins
interface Hook<HookHandler> {
    fun install(pipeline: ApplicationCallPipeline, handler: HookHandler)
}

// Event monitoring
interface Events {
    fun <T> subscribe(definition: EventDefinition<T>, handler: suspend (T) -> Unit): EventSubscription<T>
    fun <T> raise(definition: EventDefinition<T>, value: T)
}