document.getElementById('start-ranking').addEventListener('click', startRanking);
document.getElementById('help-button').addEventListener('click', toggleHelp);
document.getElementById('copy-results').addEventListener('click', copyResultsToClipboard);

let words = [];
let currentPair = [];
let scores = {};
let rounds = 0;
let currentRound = 0;
let playedPairs = new Set();
const scoreThreshold = 5;
let totalVotes = 0;
let votesDone = 0;

function startRanking() {
    const wordList = document.getElementById('word-list').value.trim().split('\n');
    words = wordList.filter(word => word.trim() !== '');
    if (words.length < 2) {
        showMessage('Please enter at least two words.');
        return;
    }

    words.forEach(word => scores[word] = 1000);
    rounds = Math.ceil(Math.log2(words.length)) + 2; // Number of rounds for Swiss-system
    currentRound = 0;
    playedPairs.clear();
    totalVotes = rounds * (words.length / 2);
    votesDone = 0;

    document.getElementById('ranking-section').classList.remove('hidden');
    document.getElementById('progress').style.width = '0%';
    updateRankingList();
    nextPair();
}

function nextPair() {
    if (currentRound >= rounds) {
        showMessage('Ranking complete!');
        disableVoteButtons();
        return;
    }

    currentPair = getNextPair();
    if (!currentPair) {
        currentRound++;
        nextPair();
        return;
    }

    document.getElementById('word1').textContent = currentPair[0];
    document.getElementById('word2').textContent = currentPair[1];

    document.getElementById('word1').onclick = () => vote(currentPair[0], currentPair[1]);
    document.getElementById('word2').onclick = () => vote(currentPair[1], currentPair[0]);
}

function getNextPair() {
    const sortedWords = Object.keys(scores).sort((a, b) => scores[b] - scores[a]);
    for (let i = 0; i < sortedWords.length - 1; i++) {
        for (let j = i + 1; j < sortedWords.length; j++) {
            if (!hasPlayed(sortedWords[i], sortedWords[j]) && Math.abs(scores[sortedWords[i]] - scores[sortedWords[j]]) <= scoreThreshold) {
                return [sortedWords[i], sortedWords[j]];
            }
        }
    }
    return null;
}

function hasPlayed(word1, word2) {
    const pair = [word1, word2].sort().join('-');
    return playedPairs.has(pair);
}

function vote(winner, loser) {
    const k = 32;
    const expectedScoreWinner = 1 / (1 + Math.pow(10, (scores[loser] - scores[winner]) / 400));
    const expectedScoreLoser = 1 - expectedScoreWinner;

    scores[winner] += k * (1 - expectedScoreWinner);
    scores[loser] += k * (0 - expectedScoreLoser);

    const pair = [winner, loser].sort().join('-');
    playedPairs.add(pair);

    votesDone++;
    updateProgress();
    updateRankingList();
    nextPair();
}

function updateProgress() {
    const progress = (votesDone / totalVotes) * 100;
    document.getElementById('progress').style.width = progress + '%';
}

function updateRankingList() {
    const rankingList = document.getElementById('ranking-list');
    rankingList.innerHTML = '';

    const sortedWords = Object.keys(scores).sort((a, b) => scores[b] - scores[a]);
    sortedWords.forEach(word => {
        const listItem = document.createElement('li');
        listItem.classList.add('ranking-item', 'p-2', 'border', 'rounded', 'bg-gray-100', 'flex', 'justify-between');
        const wordSpan = document.createElement('span');
        wordSpan.classList.add('word');
        wordSpan.textContent = word;
        const scoreSpan = document.createElement('span');
        scoreSpan.classList.add('score');
        scoreSpan.textContent = Math.round(scores[word]);
        listItem.appendChild(wordSpan);
        listItem.appendChild(scoreSpan);
        rankingList.appendChild(listItem);
    });
}

function disableVoteButtons() {
    document.getElementById('word1').disabled = true;
    document.getElementById('word2').disabled = true;
    document.getElementById('word1').classList.add('bg-gray-500', 'cursor-not-allowed');
    document.getElementById('word2').classList.add('bg-gray-500', 'cursor-not-allowed');
}

function toggleHelp() {
    const helpSection = document.getElementById('help-section');
    helpSection.classList.toggle('hidden');
    if (!helpSection.classList.contains('hidden')) {
        helpSection.style.maxHeight = helpSection.scrollHeight + "px";
    } else {
        helpSection.style.maxHeight = null;
    }
}

function showMessage(message) {
    const messageBox = document.getElementById('message-box');
    const messageText = document.getElementById('message-text');
    messageText.textContent = message;
    messageBox.classList.remove('hidden');
}

function copyResultsToClipboard() {
    const sortedWords = Object.keys(scores).sort((a, b) => scores[b] - scores[a]);
    const results = sortedWords.map(word => `${word}: ${Math.round(scores[word])}`).join('\n');
    navigator.clipboard.writeText(results).then(() => {
        const clipboardOkIcon = document.querySelector('.clipboard-ok');
        clipboardOkIcon.classList.remove('hidden');
        setTimeout(() => {
            clipboardOkIcon.classList.add('hidden');
        }, 5000);
    }).catch(err => {
        alert('Failed to copy results: ', err);
    });
}