const expandedNodeIds = new Set();

document.addEventListener('DOMContentLoaded', () => {
    const textId = window.location.pathname.split('/').pop();

    fetch('/api/texts/' + textId, { credentials: 'same-origin' })
        .then(function (res) {
            if (!res.ok) {
                if (res.status === 403) {
                    const message = document.createElement('p');
                    message.textContent =
                        "You don't have permission to view this text";
                    document.getElementById('text-detail').appendChild(message);
                } else if (res.status === 404) {
                    const message = document.createElement('p');
                    message.textContent = 'Text not found';
                    document.getElementById('text-detail').appendChild(message);
                }
                return;
            }
            return res.json();
        })
        .then(function (text) {
            if (!text) return;
            const h1 = document.createElement('h1');
            h1.textContent = text.name;
            document.getElementById('text-detail').appendChild(h1);

            return fetchAndRenderNodes(textId);
        });
});

function fetchAndRenderNodes(textId) {
    return fetch('/api/nodes/' + textId, { credentials: 'same-origin' })
        .then(res => res.json())
        .then(nodes => {
            const existing = document.querySelector('#text-detail > ul');
            if (existing) existing.remove();

            const tree = buildTree(nodes);
            const ul = renderTree(tree, textId);
            document.getElementById('text-detail').appendChild(ul);
        });
}

function buildTree(nodes) {
    const map = {};
    nodes.forEach(node => {
        map[node.id] = { ...node, children: [] };
    });

    const roots = [];
    nodes.forEach(node => {
        if (node.parentNodeId === null) {
            roots.push(map[node.id]);
        } else if (map[node.parentNodeId]) {
            map[node.parentNodeId].children.push(map[node.id]);
        }
    });

    return roots;
}

function renderTree(nodes, textId, depth = 0) {
    const ul = document.createElement('ul');
    nodes.forEach(node => {
        const li = document.createElement('li');

        const titleSpan = document.createElement('span');
        titleSpan.textContent = node.title;
        li.appendChild(titleSpan);

        const addBtn = document.createElement('button');
        addBtn.textContent = 'Add child';
        addBtn.className = 'add-child';
        addBtn.addEventListener('click', () => toggleAddForm(li, node.id, textId));
        li.appendChild(addBtn);

        const bulkBtn = document.createElement('button');
        bulkBtn.textContent = 'Bulk add children';
        bulkBtn.className = 'bulk-add-children';
        bulkBtn.addEventListener(
            'click',
            () => toggleBulkAddForm(li, node.id, textId)
        );
        li.appendChild(bulkBtn);

        if (node.children.length > 0) {
            const childUl = renderTree(node.children, textId, depth + 1);
            const childrenVisible =
                expandedNodeIds.has(node.id) || depth === 0;
            if (childrenVisible) {
                expandedNodeIds.add(node.id);
            }
            childUl.style.display = childrenVisible ? '' : 'none';

            const toggleBtn = document.createElement('button');
            toggleBtn.className = 'toggle-children';
            toggleBtn.textContent = childrenVisible ? '▼' : '▶';
            toggleBtn.addEventListener('click', () => {
                const isHidden = childUl.style.display === 'none';
                childUl.style.display = isHidden ? '' : 'none';
                toggleBtn.textContent = isHidden ? '▼' : '▶';
                if (isHidden) {
                    expandedNodeIds.add(node.id);
                } else {
                    expandedNodeIds.delete(node.id);
                }
            });

            li.appendChild(toggleBtn);
            li.appendChild(childUl);
        }

        ul.appendChild(li);
    });
    return ul;
}

function closeAllAddForms() {
    const selectors = [
        'input.child-title',
        'button.save-child',
        'input.bulk-title',
        'input.bulk-count',
        'button.save-bulk',
    ];
    selectors.forEach((selector) => {
        document
            .querySelectorAll('#text-detail ' + selector)
            .forEach((element) => element.remove());
    });
}

function toggleAddForm(li, parentNodeId, textId) {
    const existing = li.querySelector('input.child-title');
    if (existing) {
        existing.remove();
        li.querySelector('button.save-child').remove();
        return;
    }

    closeAllAddForms();

    const input = document.createElement('input');
    input.type = 'text';
    input.className = 'child-title';
    input.placeholder = 'Node title';

    const saveBtn = document.createElement('button');
    saveBtn.textContent = 'Save';
    saveBtn.className = 'save-child';

    function submit() {
        const title = input.value.trim();
        if (!title) return;

        expandedNodeIds.add(parentNodeId);
        fetch('/api/nodes', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            credentials: 'same-origin',
            body: JSON.stringify({ textId: parseInt(textId), title, parentNodeId }),
        })
            .then(res => {
                if (!res.ok) throw new Error('Failed to create node');
                return res.json();
            })
            .then(() => fetchAndRenderNodes(textId));
    }

    saveBtn.addEventListener('click', submit);
    input.addEventListener('keydown', (event) => {
        if (event.key === 'Enter') {
            event.preventDefault();
            submit();
        }
    });

    li.appendChild(input);
    li.appendChild(saveBtn);
    input.focus();
}

function toggleBulkAddForm(li, parentNodeId, textId) {
    const existing = li.querySelector('input.bulk-title');
    if (existing) {
        existing.remove();
        li.querySelector('input.bulk-count').remove();
        li.querySelector('button.save-bulk').remove();
        return;
    }

    closeAllAddForms();

    const titleInput = document.createElement('input');
    titleInput.type = 'text';
    titleInput.className = 'bulk-title';
    titleInput.placeholder = 'Title prefix';

    const countInput = document.createElement('input');
    countInput.type = 'number';
    countInput.className = 'bulk-count';
    countInput.placeholder = 'Count';
    countInput.min = '1';

    const saveBtn = document.createElement('button');
    saveBtn.textContent = 'Save';
    saveBtn.className = 'save-bulk';

    function submit() {
        const titlePrefix = titleInput.value.trim();
        const count = parseInt(countInput.value);
        if (!titlePrefix || !count || count < 1) return;

        expandedNodeIds.add(parentNodeId);
        fetch('/api/nodes/bulk', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            credentials: 'same-origin',
            body: JSON.stringify({ textId: parseInt(textId), parentNodeId, titlePrefix, count }),
        })
            .then(res => {
                if (!res.ok) throw new Error('Failed to bulk create nodes');
                return res.json();
            })
            .then(() => fetchAndRenderNodes(textId));
    }

    function submitOnEnter(event) {
        if (event.key === 'Enter') {
            event.preventDefault();
            submit();
        }
    }

    saveBtn.addEventListener('click', submit);
    titleInput.addEventListener('keydown', submitOnEnter);
    countInput.addEventListener('keydown', submitOnEnter);

    li.appendChild(titleInput);
    li.appendChild(countInput);
    li.appendChild(saveBtn);
    titleInput.focus();
}