package twentytwo

import readInputTwentyTwo

data class Section(val start: Int, val end: Int) {
    fun getSize(): Int {
        return end - start
    }
}

data class ElfSections(val firstSection: Section?, val secondSection: Section?)

fun String.toSections(): ElfSections {
    val elvesSection = this.split(",")
    val firstElfSections = elvesSection.component1().split("-")
    val firstSection = Section(firstElfSections.component1().toInt(), firstElfSections.component2()!!.toInt())
    val secondElfSections = elvesSection.component2()!!.split("-")
    val secondSection = Section(secondElfSections.component1().toInt(), secondElfSections.component2()!!.toInt())

    // sort so that the bigger section is always first
    val sections = listOf(firstSection, secondSection).sortedBy { it.getSize() }.reversed()
    return ElfSections(sections.component1(), sections.component2())
}

fun main() {
    fun part1(input: List<String>): Int {
        return input.map { it.toSections() }
            .stream()
            .filter { it.firstSection!!.start <= it.secondSection!!.start && it.firstSection.end >= it.secondSection.end }
            .count()
            .toInt()
    }

    fun part2(input: List<String>): Int {
        return input.map { it.toSections() }
            .stream()
            .filter {
                it.secondSection!!.start in it.firstSection!!.start..it.firstSection.end
                        || it.secondSection.end in it.firstSection.start..it.firstSection.end
            }
            .count()
            .toInt()
    }

    // test if implementation meets criteria from the description, like:
    val testInput = readInputTwentyTwo("Day04_test")
    check(part1(testInput).also(::println) == 2)
    check(part2(testInput).also(::println) == 4)

    val input = readInputTwentyTwo("Day04")
    println(part1(input))
    println(part2(input))
}
