import { promises as fsPromises } from "node:fs";

async function asyncReadFile(filename) {
    try {
        const contents = await fsPromises.readFile(filename, "utf-8");

        const arr = contents.split(/\r?\n/);

        return arr;
    } catch (err) {
        console.error(err);
    }
}

const countRanges = (ranges) => {
    console.log({ ranges });
    let newRanges = [...ranges];
    let overlapCount = -1;

    while (overlapCount !== 0) {
        overlapCount = 0;
        newRanges = newRanges.reduce((acc, curr) => {
            let hasOverlap = false;
            const [currStart, currEnd] = curr.split("-").map((val) => val * 1);
            acc = (acc ?? []).map((range) => {
                const [start, end] = range.split("-").map((val) => val * 1);

                // exclude ones either before or after range
                if (currStart > end || currEnd < start) return range;

                // that means that it must overlap
                hasOverlap = true;
                return `${Math.min(currStart, start)}-${Math.max(
                    currEnd,
                    end
                )}`;
            });

            if (hasOverlap) overlapCount++;
            else acc.push(curr);

            return acc;
        }, []);
    }

    console.log({ newRanges });
    return newRanges.reduce((total, curr) => {
        const [currStart, currEnd] = curr.split("-").map((val) => val * 1);
        console.log(`adding ${1 + currEnd - currStart}`);
        return total + 1 + currEnd - currStart; // +1 because it's inclusive of the end
    }, 0);
};

const parseData = (rows) => {
    let isInRanges = true;
    let freshRanges = [];
    let freshCount = 0;

    rows.forEach((row) => {
        if (isInRanges) {
            if (row === "") {
                isInRanges = false;
                return;
            }

            if (row.includes("-")) {
                freshRanges.push(row);
                return;
            }

            return;
        }
    });

    return countRanges(freshRanges);
};

const testData = `
3-5
10-14
16-20
12-18

1
5
8
11
17
32
`.trim();

const rows = await asyncReadFile("../input.txt");

console.log(`Fresh ingredient count: ${parseData(rows)}`);