package adventofcode.year2022

import adventofcode.Puzzle
import adventofcode.PuzzleInput

class Day10CathodeRayTube(customInput: PuzzleInput? = null) : Puzzle(customInput) {
    override val name = "<NAME>"

    private val instructionCycles by lazy { input.toInstructionCycles() }

    override fun partOne() = instructionCycles
        .filter { (cycle, _, _) -> cycle in setOf(20, 60, 100, 140, 180, 220) }
        .sumOf { (cycle, _, x) -> cycle * x }

    override fun partTwo() = instructionCycles
        .map { (cycle, _, x) ->
            val pixel = (cycle - 1) % SCREEN_WIDTH
            val spritePosition = listOf(x - 1, x, x + 1)

            spritePosition.contains(pixel)
        }
        .chunked(SCREEN_WIDTH)
        .joinToString(separator = "\n", prefix = "\n", postfix = "\n") { row -> row.joinToString("") { cell -> if (cell) "█" else " " } }

    companion object {
        private const val SCREEN_WIDTH = 40

        private fun String.toInstructionCycles() = lines()
            .fold(listOf(Triple("", 0, 1))) { acc, instruction ->
                val (_, _, xAfterPreviousCycle) = acc.last()

                acc + when {
                    instruction.startsWith("addx ") -> listOf(
                        Triple("noop", xAfterPreviousCycle, xAfterPreviousCycle),
                        Triple(instruction, xAfterPreviousCycle, xAfterPreviousCycle + instruction.split(" ").last().toInt())
                    )

                    else -> listOf(Triple(instruction, xAfterPreviousCycle, xAfterPreviousCycle))
                }
            }
            .mapIndexed { cycle, (instruction, xBeforeCycle, _) -> Triple(cycle, instruction, xBeforeCycle) }
            .drop(1)
    }
}
