import { readLines } from "https://deno.land/std@0.177.1/io/read_lines.ts";

async function Part1() {
    const file = await Deno.open("./Day1/input.txt");

    const lines = readLines(file);
    let last = +(await lines.next()).value;
    let descends = 0;
    for await (const depth of lines) {
        if (+depth > last) {
            descends++;
        }
        last = +depth;
    }
    return descends;
}

async function Part2(windowSize: number) {
    const file = await Deno.open("./Day1/input.txt");
    const lines = readLines(file);

    const window: number[] = new Array(windowSize);
    let descends = 0;

    for (let i = 0; i < windowSize; i++) {
        window[i] = +(await lines.next()).value;
    }

    let oldSum = window.reduce((x,y) => x+y);

    for await (const depth of lines) {
        const oldValue = window.shift() as number;
        const newSum = oldSum - oldValue + +depth;
        if (newSum > oldSum) {
            descends++;
        }
        oldSum = newSum;
        window.push(+depth);
    }
    return descends;
}

console.log("Part1: " + await Part1());

console.log("Part2: " + await Part2(3));