day04.js

const fs = require('fs').promises;

(async () => {
  console.log(`Reading input from ${__dirname}/${process.argv[2]}.txt`);
  const inputData = await fs.readFile(`${__dirname}/${process.argv[2]}.txt`);
  const inputs = inputData.toString().split('\n\n');

  const neededFields = [
    {
      string: 'byr',
      length: 4,
      isNum: true,
      minRange: 1920,
      maxRange: 2002,
    },
    {
      string: 'iyr',
      length: 4,
      isNum: true,
      minRange: 2010,
      maxRange: 2020,
    },
    {
      string: 'eyr',
      length: 4,
      isNum: true,
      minRange: 2020,
      maxRange: 2030,
    },
    {
      string: 'hgt',
      isNum: true,
    },
    {
      string: 'hcl',
      length: 7,
      regex: /#[0-9a-f]{6}/,
    },
    {
      string: 'ecl',
      length: 3,
      includesValue: ['amb', 'blu', 'brn', 'gry', 'grn', 'hzl', 'oth'],
    },
    {
      string: 'pid',
      length: 9,
      isNum: true,
      regex: /[0-9]{9}/,
    },
  ];

  let firstCount = 0;
  let secondCount = 0;
  inputs.forEach((passport) => {
    if (neededFields.every((field) => passport.includes(field.string))) {
      firstCount++;

      const fieldMap = {};
      passport = passport
        .replaceAll('\n', ' ')
        .split(' ')
        .map((field) => {
          const [key, value] = field.split(':');
          fieldMap[key] = value;
        });

      if (
        neededFields.every((field) => {
          const fieldValue = fieldMap[field.string];

          if (field.length && fieldValue.length !== field.length) {
            return false;
          }

          if (field.isNum && isNaN(parseInt(fieldValue, 10))) {
            return false;
          }

          if (field.regex && !field.regex.test(fieldValue)) {
            return false;
          }

          if (field.maxRange && parseInt(fieldValue) > field.maxRange) {
            return false;
          }

          if (field.minRange && parseInt(fieldValue) < field.minRange) {
            return false;
          }

          if (field.string === 'hgt') {
            if (!(fieldValue.includes('cm') || fieldValue.includes('in'))) {
              return false;
            }

            if (fieldValue.includes('cm')) {
              const height = parseInt(fieldValue.replace('cm', ''), 10);
              if (height > 193) {
                return false;
              }
              if (height < 150) {
                return false;
              }
            }

            if (fieldValue.includes('in')) {
              const height = parseInt(fieldValue.replace('in', ''), 10);
              if (height < 59) {
                return false;
              }
              if (height > 76) {
                return false;
              }
            }
          }

          if (
            field.includesValue &&
            !field.includesValue.includes(fieldValue)
          ) {
            return false;
          }

          return true;
        })
      ) {
        secondCount++;
      }
    }
  });
  console.log('firstCount', firstCount);
  console.log('secondCount', secondCount);
})();