package moe.kageru.kagebot.command

import arrow.core.Option
import moe.kageru.kagebot.Util
import moe.kageru.kagebot.Util.unwrap
import org.javacord.api.entity.permission.Role
import org.javacord.api.event.message.MessageCreateEvent

class Permissions(
    hasOneOf: List<String>?,
    hasNoneOf: List<String>?,
    private val onlyDM: Boolean = false
) {
    private val hasOneOf: Option<Set<Role>> = resolveRoles(hasOneOf)
    private val hasNoneOf: Option<Set<Role>> = resolveRoles(hasNoneOf)

    private fun resolveRoles(hasOneOf: List<String>?): Option<Set<Role>> {
        return Option.fromNullable(hasOneOf?.mapTo(mutableSetOf(), { Util.findRole(it).unwrap() }))
    }

    fun isAllowed(message: MessageCreateEvent): Boolean = when {
        message.messageAuthor.isBotOwner -> true
        onlyDM && !message.isPrivateMessage -> false
        // returns true if the Option is empty (case for no restrictions)
        else -> hasOneOf.forall { Util.hasOneOf(message.messageAuthor, it) }
                && hasNoneOf.forall { !Util.hasOneOf(message.messageAuthor, it) }
    }
}