const arithmeticProgression  = (n, lim) =>
  Array.from({ length: Math.ceil(lim / n) }, (_, i) => (i + 1) * n );
  
arithmeticProgression(5, 25); // [5, 10, 15, 20, 25]

const longestPalindrome = (s) => {
    if(s.length === 1) return s
    
    const odd = longestOddPalindrome(s)
    const even = longestEvenPalindrome(s)
    
    
    if(odd.length >= even.length) return odd
    if(even.length > odd.length) return even
};

const longestOddPalindrome = (s) => {    
    let longest = 0
    let longestSubStr = ""
    
    for(let i = 1; i < s.length; i++) {
        
        let currentLongest = 1
        let currentLongestSubStr = ""
        let left = i - 1
        let right = i + 1
        
        while(left >= 0 && right < s.length) {
            const leftLetter = s[left]
            const rightLetter = s[right]

            left--
            right++

            if(leftLetter === rightLetter) {
                currentLongest += 2
                currentLongestSubStr = s.slice(left+1, right)
            } else break
        }
        
                        
        if(currentLongest > longest) {
            if(currentLongestSubStr) longestSubStr = currentLongestSubStr 
            else longestSubStr = s[i]
            longest = currentLongest
        }
    }
    
    return longestSubStr
}

const longestEvenPalindrome = (s) => {    
    let longest = 0
    let longestSubStr = ""
    
    for(let i = 0; i < s.length - 1; i++) {
        if(s[i] !== s[i+1]) continue;
        
        let currentLongest = 2
        let currentLongestSubStr = ""
        let left = i - 1
        let right = i + 2
        
        while(left >= 0 && right < s.length) {
            const leftLetter = s[left]
            const rightLetter = s[right]

            left--
            right++
            
            if(leftLetter === rightLetter) {
                currentLongest += 2
                currentLongestSubStr = s.slice(left+1, right)
            } else break
        }
                
                
        if(currentLongest > longest) {
            if(currentLongestSubStr) longestSubStr = currentLongestSubStr
            else longestSubStr = s[i] + s[i+1]
    
            longest = currentLongest
        }
    }
    
    return longestSubStr
}
console.log(longestPalindrome("babad"))

//Disclaimer: I do not condone mass web scraping of ESPN websites, and this is just theoretical code that hasn't been used.

//Scrape player stats off of https://www.espn.com/nfl/team/roster/_/name/phi/philadelphia-eagles

//Example player JS object
/*
{
	"shortName": "S. Opeta",
	"name": "Sua Opeta",
	"href": "http://www.espn.com/nfl/player/_/id/3121009/sua-opeta",
	"uid": "s:20~l:28~a:3121009",
	"guid": "dec19157-e984-f981-3724-498281328c97",
	"id": "3121009",
	"height": "6' 4\"",
	"weight": "305 lbs",
	"age": 27,
	"position": "G",
	"jersey": "78",
	"birthDate": "08/15/96",
	"headshot": "https://a.espncdn.com/i/headshots/nfl/players/full/3121009.png",
	"lastName": "Sua Opeta",
	"experience": 4,
	"college": "Weber State"
}
*/

//The page needs to be focused, so you have to put this code in a bookmarklet and click the page before clicking it. Allegedly.
navigator.clipboard.writeText(JSON.stringify(
    window["__espnfitt__"].page.content.roster.groups.flatMap((group)=>{
        return group.athletes.map((athlete)=>{
            //We can assume all football players are above 100 lbs and below 1000 lbs.
            athlete.weight = parseInt(athlete.weight.substring(0,3));
            
            if(athlete.experience == "R") athlete.experience = 0;
            else athlete.experience = parseInt(athlete.experience);

            //We can assume players are at least 1 foot, or under 10 feet tall.
            athlete.inches = 12 * parseInt(athlete.height.substring(0, 1)); //Add feet in inches
            athlete.inches += parseInt(athlete.height.substring(2).replaceAll("\"", "").trim()); //Add remaining inches

            const monthDayYear = athlete.birthDate.split("/");
            athlete.birthMonth = parseInt(monthDayYear[0]);
            athlete.birthDay = parseInt(monthDayYear[1]);
            athlete.birthYear = parseInt(monthDayYear[2]);
            
            //The only really useful stuff we get from this is Height, weight, left handedness, age, position, and birthday
            return athlete;
        });
    })
, null, "\t")).then(null, ()=>{alert("That failed.")});

//Changes all the team links on this page https://www.espn.com/nfl/stats/team to the team's roster for easier scraping
$$("table > tbody > tr > td > div > div > a").forEach((elm)=>{
	elm.setAttribute("href", elm.getAttribute("href").replace("team/", "team/roster/"));
});

export const Main = () => {
    const [title, setTitle] = useState('');
    
    return (
        <ChildComponent
            title={title}
            onChange={e => setTitle(e.target.value)}
        />
    );
};

export const ChildComponent = ({ title, onChange }) => {
    return (
        <Box component="form" onSubmit={() => {}} noValidate mt={5}>
            <TextField
                fullWidth
                id="title"
                label="Title"
                name="title"
                autoComplete="title"
                autoFocus
                color="primary"
                variant="filled"
                InputLabelProps={{ shrink: true }}
                value={title}
                onChange={onChange}
            />
        </Box>
    );
};

const luhnCheck = num => {
  let arr = (num + '')
    .split('')
    .reverse()
    .map(x => parseInt(x));
  let lastDigit = arr.splice(0, 1)[0];
  let sum = arr.reduce(
    (acc, val, i) => (i % 2 !== 0 ? acc + val : acc + ((val *= 2) > 9 ? val - 9 : val)),
    0
  );
  sum += lastDigit;
  return sum % 10 === 0;
};

luhnCheck('4485275742308327'); // true
luhnCheck(6011329933655299); //  true
luhnCheck(123456789); // false

// promisify(f, true) to get array of results
function promisify(f, manyArgs = false) {
  return function (...args) {
    return new Promise((resolve, reject) => {
      function callback(err, ...results) { // our custom callback for f
        if (err) {
          reject(err);
        } else {
          // resolve with all callback results if manyArgs is specified
          resolve(manyArgs ? results : results[0]);
        }
      }

      args.push(callback);

      f.call(this, ...args);
    });
  };
}

// usage:
f = promisify(f, true);
f(...).then(arrayOfResults => ..., err => ...);