const sample = await Deno.readTextFile("sample.txt");
const input = await Deno.readTextFile("input.txt");

interface Map {
  s: number;
  d: number;
  l: number;
}

interface ParsedInput {
  seeds: number[];
  seedToSoil: Map[];
  soilToFertilizer: Map[];
  fertilizerToWater: Map[];
  waterToLight: Map[];
  lightToTemperature: Map[];
  temperatureToHumidity: Map[];
  humidityToLocation: Map[];
}

const computeMap = (maps: Map[]) => (input: number): number => {
  for (const { s, d, l } of maps) {
    if (input >= s && input < s + l) return (input - s) + d;
  }
  return input;
};

const parseInput = (input: string): ParsedInput => {
  const seeds: number[] =
    input.split("\n\n").shift()?.split(" ").slice(1).map(parseFloat) || [];

  const parsed = input.split("\n\n")
    .filter(Boolean)
    .slice(1)
    .map((map): string[] => map.split(/:\ |\ map:\ *\n*/))
    .map((
      [name, rows],
    ): [string, number[][]] => [
      name,
      rows.trim().split(/\n/).map((values) =>
        values.split(/\ /).map(parseFloat)
      ),
    ]);

  let seedToSoil: Map[] = [];
  let soilToFertilizer: Map[] = [];
  let fertilizerToWater: Map[] = [];
  let waterToLight: Map[] = [];
  let lightToTemperature: Map[] = [];
  let temperatureToHumidity: Map[] = [];
  let humidityToLocation: Map[] = [];

  parsed.forEach((
    [name, mapValues],
  ) => {
    const maps = mapValues.map(([d, s, l]) => ({ d, s, l }));
    if (name === "seed-to-soil") {
      seedToSoil = maps;
    } else if (name === "soil-to-fertilizer") {
      soilToFertilizer = maps;
    } else if (name === "fertilizer-to-water") {
      fertilizerToWater = maps;
    } else if (name === "water-to-light") {
      waterToLight = maps;
    } else if (name === "light-to-temperature") {
      lightToTemperature = maps;
    } else if (name === "temperature-to-humidity") {
      temperatureToHumidity = maps;
    } else if (name === "humidity-to-location") {
      humidityToLocation = maps;
    }
  });

  return {
    seeds,
    seedToSoil,
    soilToFertilizer,
    fertilizerToWater,
    waterToLight,
    lightToTemperature,
    temperatureToHumidity,
    humidityToLocation,
  };
};

const solvePart1 = (data: string): number => {
  const {
    seeds,
    seedToSoil,
    soilToFertilizer,
    fertilizerToWater,
    waterToLight,
    lightToTemperature,
    temperatureToHumidity,
    humidityToLocation,
  } = parseInput(data);

  return seeds
    .map(computeMap(seedToSoil))
    .map(computeMap(soilToFertilizer))
    .map(computeMap(fertilizerToWater))
    .map(computeMap(waterToLight))
    .map(computeMap(lightToTemperature))
    .map(computeMap(temperatureToHumidity))
    .map(computeMap(humidityToLocation))
    .reduce((m, v) => Math.min(m, v));
};

console.log("Sample:", solvePart1(sample)); // 35
console.log("Input", solvePart1(input)); // 265018614

const getRanges = (list: number[]): [number, number][] => {
  const result: [number, number][] = [];
  for (let i = 0; i < list.length; i += 2) {
    result.push([list[i], list[i + 1]]);
  }
  return result;
};

const mapRange = (s: number, l: number, fn: (n: number) => void): void => {
  for (let i = s; i < s + l; i += 1) {
    fn(i);
  }
};

const solvePart2 = (data: string): number => {
  const {
    seeds: seedRanges,
    seedToSoil,
    soilToFertilizer,
    fertilizerToWater,
    waterToLight,
    lightToTemperature,
    temperatureToHumidity,
    humidityToLocation,
  } = parseInput(data);

  console.log("getRanges(seedRanges)", getRanges(seedRanges));

  const fn = (n: number): number =>
    computeMap(humidityToLocation)(
      computeMap(temperatureToHumidity)(
        computeMap(lightToTemperature)(
          computeMap(waterToLight)(
            computeMap(fertilizerToWater)(
              computeMap(soilToFertilizer)(computeMap(seedToSoil)(n)),
            ),
          ),
        ),
      ),
    );

  let lowest = Number.MAX_VALUE
  getRanges(seedRanges).forEach(([s, l]) => {
    console.log("range", s, lowest);
    mapRange(s, l, (n) => {
      lowest = Math.min(lowest, fn(n));
    });
  });

  return lowest;
};

console.log("Sample:", solvePart2(sample)); // 46
console.log("Input", solvePart2(input)); // 63179500