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

async function Part1(generations: number) {
    const file = await Deno.open("./Day11/input.txt");
    const lines = readLines(file);

    let flashes = 0;
    const levels: number[][] = [];
    const neighbours = [[-1,-1],[-1,0],[-1,1],[0,-1],[0,1],[1,-1],[1,0],[1,1]]

    for await (const line of lines) {
        levels.push([]);
        const initialLevels = line.split("");
        for (const n of initialLevels) {
            levels[levels.length - 1].push(+n);
        }
    }

    for (let g = 0; g < generations; g++) {
        const coords: number[][] = []
        for (const i in levels) {
            for (const j in levels[i]) {
                coords.push([+i,+j]);
            }
        }
        
        while (coords.length != 0) {
            const [i,j]: number[] = coords.pop()!;
            if (levels[i][j] >= 9) {
                flashes++;
                levels[i][j] = -1;
                for (const [a,b] of neighbours) {
                    if (!(0 <= i + a && i + a <= levels.length - 1 && 0 <= j + b && j + b <= levels[i].length - 1)) {
                        continue
                    }
                    if (levels[i + a][j + b] != -1) {
                        levels[i + a][j + b]++;
                        if (levels[i + a][j + b] > 9) {
                            coords.push([i + a, j + b]);
                        }
                    }
                }
            } else {
                if (levels[i][j] != -1) {
                    levels[i][j]++;
                }
            }
        }

        for (const i in levels) {
            for (const j in levels[i]) {
                if (levels[i][j] == -1) {
                    levels[i][j] = 0;
                }
            }
        }

    }
    return flashes
}

async function Part2() {
    const file = await Deno.open("./Day11/input.txt");
    const lines = readLines(file);

    let lastFlashes = 0;
    let generation = 0;
    const levels: number[][] = [];
    const neighbours = [[-1,-1],[-1,0],[-1,1],[0,-1],[0,1],[1,-1],[1,0],[1,1]]

    for await (const line of lines) {
        levels.push([]);
        const initialLevels = line.split("");
        for (const n of initialLevels) {
            levels[levels.length - 1].push(+n);
        }
    }

    while (lastFlashes != levels.length * levels[0].length) {
        lastFlashes = 0;
        generation++;

        const coords: number[][] = []
        for (const i in levels) {
            for (const j in levels[i]) {
                coords.push([+i,+j]);
            }
        }
        
        while (coords.length != 0) {
            const [i,j]: number[] = coords.pop()!;
            if (levels[i][j] >= 9) {
                lastFlashes++;
                levels[i][j] = -1;
                for (const [a,b] of neighbours) {
                    if (!(0 <= i + a && i + a <= levels.length - 1 && 0 <= j + b && j + b <= levels[i].length - 1)) {
                        continue
                    }
                    if (levels[i + a][j + b] != -1) {
                        levels[i + a][j + b]++;
                        if (levels[i + a][j + b] > 9) {
                            coords.push([i + a, j + b]);
                        }
                    }
                }
            } else {
                if (levels[i][j] != -1) {
                    levels[i][j]++;
                }
            }
        }

        for (const i in levels) {
            for (const j in levels[i]) {
                if (levels[i][j] == -1) {
                    levels[i][j] = 0;
                }
            }
        }

    }
    return generation

}

console.log("Part1: " + await Part1(100));
console.log("Part2: " + await Part2());