/*
 *
 *  * Copyright 2019 New Vector Ltd
 *  *
 *  * Licensed under the Apache License, Version 2.0 (the "License");
 *  * you may not use this file except in compliance with the License.
 *  * You may obtain a copy of the License at
 *  *
 *  *     http://www.apache.org/licenses/LICENSE-2.0
 *  *
 *  * Unless required by applicable law or agreed to in writing, software
 *  * distributed under the License is distributed on an "AS IS" BASIS,
 *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  * See the License for the specific language governing permissions and
 *  * limitations under the License.
 *
 */

package im.vector.riotredesign.core.extensions

/**
 * Returns the last element yielding the smallest value of the given function or `null` if there are no elements.
 */
public inline fun <T, R : Comparable<R>> Iterable<T>.lastMinBy(selector: (T) -> R): T? {
    val iterator = iterator()
    if (!iterator.hasNext()) return null
    var minElem = iterator.next()
    var minValue = selector(minElem)
    while (iterator.hasNext()) {
        val e = iterator.next()
        val v = selector(e)
        if (minValue >= v) {
            minElem = e
            minValue = v
        }
    }
    return minElem
}