import { readFileSync } from 'fs'

function hash(input: string): number {
    let curr = 0
    for (let i = 0; i < input.length; i++) {
        const code = input[i].charCodeAt(0)
        curr += code
        curr *= 17
        curr %= 256
    }
    return curr
}

function part1(input: string): number {
    const strings = input.replace(/\n+/, '').split(',')
    return strings.reduce((acc, s) => acc + hash(s), 0)
}

function part2(input: string): number {
    const boxes = Array.from({ length: 256 }, () => new Map<string, number>())
    const strings = input.replace(/\n+/, '').split(',')

    for (let string of strings) {
        const [label, op, n] = string.split(/\b/)
        const index = hash(label)
        if (op === '=') {
            boxes[index].set(label, Number(n))
        } else {
            boxes[index].delete(label)
        }
    }

    let total = 0
    for (let i = 0; i < boxes.length; i++) {
        let slot = 1
        for (const focalLength of boxes[i].values()) {
            total += (i + 1) * slot++ * focalLength
        }
    }

    return total
}

let input = 'rn=1,cm-,qp=3,cm=2,qp-,pc=4,ot=9,ab=5,pc-,pc=6,ot=7'
input = readFileSync('day15.txt', { encoding: 'utf8' })

console.log('part 1:', part1(input))
console.log('part 2:', part2(input))