const { Glib, Maps } = require('../../lib');

const parse = (input) =>
  Glib.fromLines(input).map((line) => {
    const [color, heldString] = line.split(' bags contain ');
    const children = [];

    if (heldString !== 'no other bags.') {
      const helds = heldString.split(', ');
      for (const held of helds) {
        const [heldDef] = held.split(' bag');
        const [heldNum, ...heldColorArr] = heldDef.split(' ');
        const heldColor = heldColorArr.join(' ');
        children.push({
          count: BigInt(heldNum),
          color: heldColor,
        });
      }
    }

    return { color, children };
  });

const parseChildren = (input) =>
  parse(input).reduce((map, { color, children }) => {
    map.set(color, children);
    return map;
  }, new Map());

const parseParents = (input) =>
  parse(input).reduce((map, { color: parentColor, children }) => {
    for (const { color } of children) {
      let parent;
      map.set(color, (parent = map.get(color) || new Set()));
      parent.add(parentColor);
    }
    return map;
  }, new Map());

const childrenCount = (start, graph) => {
  const children = graph.get(start) || [];
  let count = BigInt(0);
  for (const child of children) {
    count += child.count;
    count += childrenCount(child.color, graph) * child.count;
  }

  return count;
};

module.exports = {
  '1': (input) => {
    const parents = parseParents(input);

    const found = new Set(parents.get('shiny gold'));
    let lastCount = 0;
    while (lastCount !== found.size) {
      lastCount = found.size;
      for (const color of found) {
        for (const addedColor of parents.get(color) || []) {
          found.add(addedColor);
        }
      }
    }
    return lastCount;
  },
  '2': (input) => {
    return childrenCount('shiny gold', parseChildren(input));
  },
};