Daemon Connection Management

/**
 * Connect to a Kotlin compiler daemon service
 * @param compilerId Identifies the compiler version and classpath
 * @param daemonJVMOptions JVM configuration for the daemon
 * @param daemonOptions Daemon-specific configuration options
 * @param reportingTargets Where to send diagnostic and status messages
 * @param autostart Whether to start a new daemon if none found
 * @param checkId Whether to verify compiler ID matches
 * @return CompileService instance or null if connection failed
 */
fun connectToCompileService(
    compilerId: CompilerId,
    daemonJVMOptions: DaemonJVMOptions,
    daemonOptions: DaemonOptions,
    reportingTargets: DaemonReportingTargets,
    autostart: Boolean = true,
    checkId: Boolean = true
): CompileService?

import org.jetbrains.kotlin.daemon.client.KotlinCompilerClient
import org.jetbrains.kotlin.daemon.common.*

val compilerId = CompilerId().apply {
    compilerClasspath = listOf("/path/to/kotlin-compiler.jar")
}

val daemonJVMOptions = DaemonJVMOptions().apply {
    maxMemory = "2g"
    maxPermSize = "512m"
}

val daemonOptions = DaemonOptions().apply {
    runFilesPath = "/tmp/kotlin-daemon"
}

val reportingTargets = DaemonReportingTargets(out = System.out)

val compileService = KotlinCompilerClient.connectToCompileService(
    compilerId = compilerId,
    daemonJVMOptions = daemonJVMOptions,
    daemonOptions = daemonOptions,
    reportingTargets = reportingTargets,
    autostart = true
)

/**
 * Connect to daemon with explicit client flag file
 * @param compilerId Compiler identification
 * @param clientAliveFlagFile File indicating client is alive
 * @param daemonJVMOptions JVM options for daemon
 * @param daemonOptions Daemon configuration
 * @param reportingTargets Diagnostic reporting targets
 * @param autostart Whether to start daemon if not found
 * @return CompileService instance or null
 */
fun connectToCompileService(
    compilerId: CompilerId,
    clientAliveFlagFile: File,
    daemonJVMOptions: DaemonJVMOptions,
    daemonOptions: DaemonOptions,
    reportingTargets: DaemonReportingTargets,
    autostart: Boolean = true
): CompileService?

/**
 * Connect to daemon and lease a compilation session
 * @param compilerId Compiler identification
 * @param clientAliveFlagFile Client lifecycle flag file
 * @param daemonJVMOptions JVM configuration
 * @param daemonOptions Daemon configuration
 * @param reportingTargets Diagnostic targets
 * @param autostart Whether to start daemon automatically
 * @param leaseSession Whether to lease an exclusive session
 * @param sessionAliveFlagFile Session lifecycle flag file
 * @return CompileServiceSession with service and session ID
 */
fun connectAndLease(
    compilerId: CompilerId,
    clientAliveFlagFile: File,
    daemonJVMOptions: DaemonJVMOptions,
    daemonOptions: DaemonOptions,
    reportingTargets: DaemonReportingTargets,
    autostart: Boolean,
    leaseSession: Boolean,
    sessionAliveFlagFile: File? = null
): CompileServiceSession?

/**
 * Shutdown a compiler daemon
 * @param compilerId Identifies which daemon to shut down
 * @param daemonOptions Daemon configuration for finding the daemon
 */
fun shutdownCompileService(compilerId: CompilerId, daemonOptions: DaemonOptions): Unit

/**
 * Shutdown daemon with default options
 * @param compilerId Identifies which daemon to shut down
 */
fun shutdownCompileService(compilerId: CompilerId): Unit

/**
 * Lease a compilation session from the daemon
 * @param compilerService The daemon service
 * @param aliveFlagPath Path to session alive flag file
 * @return Session ID for the leased session
 */
fun leaseCompileSession(compilerService: CompileService, aliveFlagPath: String?): Int

/**
 * Release a previously leased compilation session
 * @param compilerService The daemon service
 * @param sessionId Session ID to release
 */
fun releaseCompileSession(compilerService: CompileService, sessionId: Int): Unit

/**
 * Get or create a client flag file for daemon communication
 * @param daemonOptions Daemon configuration containing flag file path
 * @return File representing the client alive flag
 */
fun getOrCreateClientFlagFile(daemonOptions: DaemonOptions): File

/**
 * Detect compiler classpath automatically
 * @return List of classpath entries or null if detection failed
 */
fun detectCompilerClasspath(): List<String>?

/**
 * Represents a daemon service with an associated session
 * @param compileService The daemon service instance
 * @param sessionId The session ID (CompileService.NO_SESSION for no session)
 */
data class CompileServiceSession(
    val compileService: CompileService,
    val sessionId: Int
)

/**
 * Configuration options for the daemon client
 * @param stop Whether to stop/shutdown mode
 */
data class ClientOptions(
    var stop: Boolean = false
) : OptionsGroup

val compileService = KotlinCompilerClient.connectToCompileService(
    compilerId, daemonJVMOptions, daemonOptions, reportingTargets
)

compileService?.let { service ->
    // Use the service for compilation
    // ...
    
    // Optionally shutdown when done
    KotlinCompilerClient.shutdownCompileService(compilerId, daemonOptions)
}

val session = KotlinCompilerClient.connectAndLease(
    compilerId, clientFlagFile, daemonJVMOptions, daemonOptions,
    reportingTargets, autostart = true, leaseSession = true, sessionFlagFile
)

session?.let { (service, sessionId) ->
    try {
        // Use service with sessionId for exclusive access
        // ...
    } finally {
        KotlinCompilerClient.releaseCompileSession(service, sessionId)
    }
}

val compilerId = CompilerId().apply {
    val detectedClasspath = KotlinCompilerClient.detectCompilerClasspath()
    if (detectedClasspath != null) {
        compilerClasspath = detectedClasspath
    } else {
        throw IllegalStateException("Could not detect Kotlin compiler classpath")
    }
}