aoc2020 day4.js

function IDCheckp1()
{
  const lines = document.getElementsByTagName('pre')[0].innerHTML.split('\n');
  const minFields = ['byr', 'iyr', 'eyr', 'hgt', 'hcl', 'ecl', 'pid'];
  let fields = [];
  const validCount = lines.reduce((count, line) =>
  {
    if(line.trim() === '')
    {
      if(minFields.every(field => fields.indexOf(field) > -1))
      {
        count++;
      }
      fields = [];
    }
    else
    {
      fields = fields.concat(line.split(' ')
                                 .map(kvp => kvp.split(':')[0]));
    }           
    return count;
  },0);
  
  return validCount;
}

function IDCheckp2()
{
  const lines = document.getElementsByTagName('pre')[0].innerHTML.split('\n');
  const minFields = ['byr', 'iyr', 'eyr', 'hgt', 'hcl', 'ecl', 'pid'];
  let fields = [];
  let parts = [];
  const validCount = lines.reduce((count, line) =>
  {
    if(line.trim() === '')
    {
      if(minFields.every(field => fields.indexOf(field) > -1))
      {
        let ID = JSON.parse('{'+parts.join(',')+'}');
        if(isValidID(ID))
        {
          count++;
        }
      }
      fields = [];
      parts = [];
    }
    else
    {
      fields = fields.concat(line.split(' ')
                                 .map(kvp => kvp.split(':')[0]));
      parts = parts.concat(line.split(' ')
                               .map(kvp =>
                                    {
                                      let [key, value] = kvp.split(':');
                                      return `"${key}":"${value}"`;
                                    }));

    }           
    return count;
  },0);
  
  function isValidID(ID)
  {
    return (
       ID['byr'].match(/^(19[2-9]\d|200[012])$/)
    && ID['iyr'].match(/^20(1\d|20)$/)
    && ID['eyr'].match(/^20(2\d|30)$/)
    && isValidHeight(ID['hgt'])
    && ID['hcl'].match(/^#[0-9a-fA-F]{6}$/)
    && ['amb','blu','brn','gry','grn','hzl','oth'].includes(ID['ecl'])
    && ID['pid'].match(/^\d{9}$/)
    );
  }
  
  function isValidHeight(heightstr)
  {
    let heightparts = heightstr.match(/^(\d+)(cm|in)$/);
    if(heightparts)
    {
      let height = parseInt(heightparts[1], 10);
      if(heightparts[2] == 'cm')
      {
        return Math.min(Math.max(height, 150), 193) == height;
      }
      else if(heightparts[2] == 'in')
      {
        return Math.min(Math.max(height, 59), 76) == height;
      }
    }
    return false;
  }
  
  return validCount; 
}