const USERNAME_KEY = 'scrumPoker.username';

const SCALE_PRESETS = {
    fibonacci: ['0', '1', '2', '3', '5', '8', '13', '21', '?'],
    tshirt: ['XS', 'S', 'M', 'L', 'XL', '?'],
    'powers-of-two': ['1', '2', '4', '8', '16', '32', '?'],
};

const themeToggleBtn = document.getElementById('theme-toggle');
const roomConfigForm = document.getElementById('room-config-form');
const statusLine = document.getElementById('config-status');
const scaleSelect = document.getElementById('estimation-scale');
const maxPeopleInput = document.getElementById('max-people');
const previewScale = document.getElementById('preview-scale');
const previewMaxPeople = document.getElementById('preview-max-people');
const previewCards = document.getElementById('preview-cards');
const customCardInput = document.getElementById('custom-card');
const addCardButton = document.getElementById('add-card');
const usernameInput = document.getElementById('username');

let isDarkMode = false;
let nextCardID = 1;
let currentCards = [];
let draggingCardID = '';

const savedUsername = localStorage.getItem(USERNAME_KEY);
if (savedUsername && !usernameInput.value) {
    usernameInput.value = savedUsername;
}

themeToggleBtn.addEventListener('click', () => {
    isDarkMode = !isDarkMode;
    if (isDarkMode) {
        document.documentElement.setAttribute('data-theme', 'dark');
        themeToggleBtn.textContent = 'Light Mode';
        return;
    }

    document.documentElement.removeAttribute('data-theme');
    themeToggleBtn.textContent = 'Dark Mode';
});

function createCard(value) {
    return { id: String(nextCardID++), value: value.toString() };
}

function getCardsForScale(scale) {
    return (SCALE_PRESETS[scale] || SCALE_PRESETS.fibonacci).map(createCard);
}

function captureCardPositions() {
    const positions = new Map();
    previewCards.querySelectorAll('.preview-card').forEach((el) => {
        positions.set(el.dataset.cardId, el.getBoundingClientRect());
    });
    return positions;
}

function animateReflow(previousPositions) {
    previewCards.querySelectorAll('.preview-card').forEach((el) => {
        const previousRect = previousPositions.get(el.dataset.cardId);
        if (!previousRect) {
            return;
        }

        const nextRect = el.getBoundingClientRect();
        const deltaX = previousRect.left - nextRect.left;
        const deltaY = previousRect.top - nextRect.top;
        if (!deltaX && !deltaY) {
            return;
        }

        el.style.transform = `translate(${deltaX}px, ${deltaY}px)`;
        requestAnimationFrame(() => {
            el.style.transform = 'translate(0, 0)';
        });
    });
}

function removeCard(cardID) {
    const cardEl = previewCards.querySelector(`[data-card-id="${cardID}"]`);
    if (!cardEl) {
        return;
    }

    cardEl.classList.add('is-removing');
    cardEl.addEventListener('animationend', () => {
        const previousPositions = captureCardPositions();
        currentCards = currentCards.filter((card) => card.id !== cardID);
        renderCards(previousPositions);
    }, { once: true });
}

function reorderCard(fromID, toID) {
    if (fromID === toID) {
        return;
    }

    const fromIndex = currentCards.findIndex((card) => card.id === fromID);
    const toIndex = currentCards.findIndex((card) => card.id === toID);
    if (fromIndex < 0 || toIndex < 0) {
        return;
    }

    const previousPositions = captureCardPositions();
    const [moved] = currentCards.splice(fromIndex, 1);
    currentCards.splice(toIndex, 0, moved);
    renderCards(previousPositions);
}

function buildCardElement(card) {
    const cardEl = document.createElement('div');
    cardEl.className = 'preview-card';
    cardEl.dataset.cardId = card.id;
    cardEl.textContent = card.value;
    cardEl.draggable = true;

    const removeBtn = document.createElement('button');
    removeBtn.type = 'button';
    removeBtn.className = 'preview-card-remove';
    removeBtn.textContent = 'X';
    removeBtn.setAttribute('aria-label', `Remove ${card.value}`);
    removeBtn.addEventListener('click', (event) => {
        event.stopPropagation();
        removeCard(card.id);
    });

    cardEl.addEventListener('dragstart', () => {
        draggingCardID = card.id;
        cardEl.classList.add('dragging');
    });

    cardEl.addEventListener('dragend', () => {
        draggingCardID = '';
        cardEl.classList.remove('dragging');
    });

    cardEl.addEventListener('dragover', (event) => {
        event.preventDefault();
    });

    cardEl.addEventListener('drop', (event) => {
        event.preventDefault();
        if (!draggingCardID) {
            return;
        }
        reorderCard(draggingCardID, card.id);
    });

    cardEl.appendChild(removeBtn);
    return cardEl;
}

function renderCards(previousPositions = new Map()) {
    previewCards.innerHTML = '';
    currentCards.forEach((card) => {
        previewCards.appendChild(buildCardElement(card));
    });

    animateReflow(previousPositions);
}

function resetCardsForScale() {
    const previousPositions = captureCardPositions();
    currentCards = getCardsForScale(scaleSelect.value);
    renderCards(previousPositions);
}

function updatePreviewMeta() {
    previewScale.textContent = `Scale: ${scaleSelect.value}`;
    previewMaxPeople.textContent = `Max: ${maxPeopleInput.value || 0}`;
}

addCardButton.addEventListener('click', () => {
    const value = customCardInput.value.trim();
    if (!value) {
        return;
    }

    const previousPositions = captureCardPositions();
    currentCards.push(createCard(value.slice(0, 8)));
    renderCards(previousPositions);
    customCardInput.value = '';
    customCardInput.focus();
});

customCardInput.addEventListener('keydown', (event) => {
    if (event.key === 'Enter') {
        event.preventDefault();
        addCardButton.click();
    }
});

scaleSelect.addEventListener('change', () => {
    resetCardsForScale();
    updatePreviewMeta();
    statusLine.textContent = 'Card deck reset to selected estimation scale.';
});

maxPeopleInput.addEventListener('input', updatePreviewMeta);

roomConfigForm.addEventListener('submit', async (event) => {
    event.preventDefault();

    const formData = new FormData(roomConfigForm);
    const username = (formData.get('username') || '').toString().trim();
    const roomName = (formData.get('roomName') || '').toString().trim();

    if (!username || !roomName) {
        statusLine.textContent = 'Room name and username are required.';
        return;
    }

    localStorage.setItem(USERNAME_KEY, username);

    const payload = {
        roomName,
        creatorUsername: username,
        maxPeople: Number(formData.get('maxPeople') || 50),
        cards: currentCards.map((card) => card.value),
        allowSpectators: Boolean(formData.get('allowSpectators')),
        anonymousVoting: Boolean(formData.get('anonymousVoting')),
        autoReset: Boolean(formData.get('autoReset')),
        revealMode: (formData.get('revealMode') || 'manual').toString(),
        votingTimeoutSec: Number(formData.get('votingTimeoutSec') || 0),
        password: (formData.get('password') || '').toString(),
    };

    statusLine.textContent = 'Creating room...';

    try {
        const response = await fetch('/api/rooms', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify(payload),
        });

        const data = await response.json();
        if (!response.ok) {
            statusLine.textContent = data.error || 'Failed to create room.';
            return;
        }

        const target = `/room/${encodeURIComponent(data.roomId)}?participantId=${encodeURIComponent(data.creatorParticipantId)}&adminToken=${encodeURIComponent(data.adminToken)}`;
        window.location.assign(target);
    } catch (err) {
        statusLine.textContent = 'Network error while creating room.';
    }
});

roomConfigForm.addEventListener('reset', () => {
    window.setTimeout(() => {
        updatePreviewMeta();
        resetCardsForScale();
        statusLine.textContent = 'Room settings reset to defaults.';
    }, 0);
});

updatePreviewMeta();
resetCardsForScale();