commonMain.com.github.ajalt.clikt.parameters.groups.CoOccurringOptionGroup.kt Maven / Gradle / Ivy

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package com.github.ajalt.clikt.parameters.groups

import com.github.ajalt.clikt.core.CliktCommand
import com.github.ajalt.clikt.core.Context
import com.github.ajalt.clikt.output.HelpFormatter
import com.github.ajalt.clikt.parameters.internal.NullableLateinit
import com.github.ajalt.clikt.parameters.options.Option
import com.github.ajalt.clikt.parsers.OptionParser
import kotlin.properties.ReadOnlyProperty
import kotlin.reflect.KProperty

class CoOccurringOptionGroup(
        internal val group: GroupT,
        private val transform: (occurred: Boolean?, group: GroupT, context: Context) -> OutT
) : ParameterGroupDelegate {
    override val groupName: String? get() = group.groupName
    override val groupHelp: String? get() = group.groupHelp
    private var value: OutT by NullableLateinit("Cannot read from option delegate before parsing command line")
    private var occurred = false

    override fun provideDelegate(thisRef: CliktCommand, prop: KProperty<*>): ReadOnlyProperty {
        thisRef.registerOptionGroup(this)
        for (option in group.options) {
            option.parameterGroup = this
            option.groupName = groupName
            thisRef.registerOption(option)
        }
        return this
    }

    override fun getValue(thisRef: CliktCommand, property: KProperty<*>): OutT = value

    override fun finalize(context: Context, invocationsByOption: Map>) {
        occurred = invocationsByOption.isNotEmpty()
        if (occurred) group.finalize(context, invocationsByOption)
        value = transform(occurred, group, context)
    }

    override fun postValidate(context: Context) {
        if (occurred) group.postValidate(context)
    }
}

/**
 * Make this group a co-occurring group.
 *
 * The group becomes nullable. At least one option in the group must be [required]. Of none of the
 * options in the group are given on the command line, the group is null and none of the `required`
 * constraints are enforced. If any option in the group is given, all `required` options in the
 * group must be given as well.
 */
fun  T.cooccurring(): CoOccurringOptionGroup {
    require(options.any { HelpFormatter.Tags.REQUIRED in it.helpTags }) { "At least one option in a co-occurring group must use `required()`" }
    return CoOccurringOptionGroup(this) { occurred, g, _ ->
        if (occurred == true) g
        else null
    }
}