package com.example

import kotlin.script.experimental.annotations.KotlinScript
import kotlin.script.experimental.api.EvaluationResult
import kotlin.script.experimental.api.ResultValue
import kotlin.script.experimental.api.ResultWithDiagnostics
import kotlin.script.experimental.host.toScriptSource
import kotlin.script.experimental.jvm.dependenciesFromCurrentContext
import kotlin.script.experimental.jvm.jvm
import kotlin.script.experimental.jvmhost.BasicJvmScriptingHost
import kotlin.script.experimental.jvmhost.createJvmCompilationConfigurationFromTemplate

@KotlinScript(fileExtension = "config.kts")
abstract class ConfigurationScript {
    var aString = ""
    var anInt = 0
}

val compilationConfiguration = createJvmCompilationConfigurationFromTemplate<ConfigurationScript> {
    jvm {
        dependenciesFromCurrentContext(
            // TODO: You should put the name of the libraries that you want to be accessible from
            //  the scripts here instead of using the whole classpath.
            wholeClasspath = true
        )
    }
}

fun BasicJvmScriptingHost.evalScript(script: String): ResultWithDiagnostics<EvaluationResult> {
    return eval(script.toScriptSource("script.config.kts"), compilationConfiguration, null)
}

fun main() {
    val host = BasicJvmScriptingHost()

    println("Executing script...")
    val result = host.evalScript("""
     aString = "Hello World"
     anInt = 42
   """.trimIndent())
    println("Executed script")

    // Print reports.
    result.reports.forEach { report ->
        println("[${report.severity}] ${report.message}" + (report.exception?.let { ": $it" } ?: ""))
    }

    // Retrieve script instance.
    val instance = when (result) {
        is ResultWithDiagnostics.Success -> when (val value = result.value.returnValue) {
            is ResultValue.Value -> value.scriptInstance
            is ResultValue.UnitValue -> value.scriptInstance
            ResultValue.Unit -> null
        }
        is ResultWithDiagnostics.Failure -> null
    } as? ConfigurationScript

    instance?.let {
        println("aString = ${it.aString}") // should print "Hello World"
        println("anInt = ${it.anInt}") // should print 42
    }
}