// --- Basic Todo Model ---
const STORAGE_KEY = 'todos-v1';
const CATEGORY_KEY = 'todo-categories';
let todos = [];
let categories = [];

function loadTodos() {
    todos = JSON.parse(localStorage.getItem(STORAGE_KEY) || '[]');
    categories = JSON.parse(localStorage.getItem(CATEGORY_KEY) || '[]');
}

function saveTodos() {
    localStorage.setItem(STORAGE_KEY, JSON.stringify(todos));
    localStorage.setItem(CATEGORY_KEY, JSON.stringify(categories));
}

function getNextId() {
    return todos.length ? Math.max(...todos.map(t => t.id)) + 1 : 1;
}

function renderForm() {
    const form = document.getElementById('todo-form');
    form.innerHTML = `
      <div class="form-section">
        <label for="task">Task Description</label>
        <input type="text" id="task" placeholder="Task Description" required>
      </div>

      <div class="form-section grid-3">
        <div>
          <label for="creation-date">Creation Date</label>
          <input type="date" id="creation-date" title="Creation Date">
        </div>
        <div>
          <label for="next-date">Next Planned Work Date</label>
          <input type="date" id="next-date" title="Next Planned Work Date">
        </div>
        <div>
          <label for="due-date">Due Date</label>
          <input type="date" id="due-date" title="Due Date">
        </div>
      </div>

      <div class="form-section grid-3">
        <div>
          <label for="status">Status</label>
          <select id="status">
            <option value="">(Blank)</option>
            <option value="Busy">Busy</option>
            <option value="Done">Done</option>
            <option value="W4A">W4A</option>
          </select>
        </div>
        <div>
          <label for="urgent">Urgent (1-7)</label>
          <input type="number" id="urgent" min="1" max="7" placeholder="Urgent (1-7)">
        </div>
        <div>
          <label for="importance">Importance (1-7)</label>
          <input type="number" id="importance" min="1" max="7" placeholder="Importance (1-7)">
        </div>
      </div>

      <div class="form-section grid-2">
        <div>
          <label for="time-estimation">Time Estimation (min)</label>
          <input type="number" id="time-estimation" min="0" placeholder="Time Est. (min)">
        </div>
        <div>
          <label for="actual-time">Actual Time Spent (min)</label>
          <input type="number" id="actual-time" min="0" placeholder="Actual Time (min)">
        </div>
      </div>

      <div class="form-section grid-2">
        <div>
          <label for="category">Category</label>
          <input type="text" id="category" placeholder="Category" list="category-list">
          <datalist id="category-list"></datalist>
        </div>
        <div>
          <label for="linked-tasks">Link with other tasks (IDs, comma separated)</label>
          <input type="text" id="linked-tasks" placeholder="Link with other tasks (IDs, comma separated)">
        </div>
      </div>

      <div class="form-section grid-2">
        <div>
          <label for="coms">Coms URL</label>
          <input type="url" id="coms" placeholder="Coms URL">
        </div>
        <div>
          <label for="link">Link URL</label>
          <input type="url" id="link" placeholder="Link URL">
        </div>
      </div>

      <div class="form-section">
        <label for="comments">Comments</label>
        <textarea id="comments" placeholder="Comments"></textarea>
      </div>

      <button type="submit" class="add-todo-btn">Add Todo</button>
    `;
    // Autocomplete for categories
    const datalist = document.getElementById('category-list');
    datalist.innerHTML = categories.map(cat => `<option value="${cat}">`).join('');
}

function renderTodos() {
    const list = document.getElementById('todos-list');
    if (!todos.length) {
        list.innerHTML = '<em>No todos yet.</em>';
        return;
    }
    list.innerHTML = todos.map(todo => `
        <div class="todo-item">
            <div class="field"><b>ID:</b> ${todo.id}</div>
            <div class="field"><b>Created:</b> ${todo.creationDate}</div>
            <div class="field"><b>Next:</b> ${todo.nextDate || ''}</div>
            <div class="field"><b>Due:</b> ${todo.dueDate || ''}</div>
            <div class="field status-${todo.status || 'blank'}"><b>Status:</b> ${todo.status || ''}</div>
            <div class="field urgent"><b>Urgent:</b> ${todo.urgent}</div>
            <div class="field importance"><b>Importance:</b> ${todo.importance}</div>
            <div class="field prio"><b>Prio:</b> ${todo.prio}</div>
            <div class="field"><b>Est.:</b> ${todo.timeEstimation}m</div>
            <div class="field"><b>Spent:</b> ${todo.actualTime}m</div>
            <div class="field"><b>Category:</b> ${todo.category || ''}</div>
            <div class="field"><b>Task:</b> ${todo.task}</div>
            <div class="field"><b>Coms:</b> ${todo.coms ? `<a href="${todo.coms}" target="_blank">Link</a>` : ''}</div>
            <div class="field"><b>Link:</b> ${todo.link ? `<a href="${todo.link}" target="_blank">Link</a>` : ''}</div>
            <div class="field"><b>Comments:</b> ${todo.comments || ''}</div>
            <div class="field"><b>Linked:</b> ${todo.linkedTasks || ''}</div>
        </div>
    `).join('');
}

function addTodo(e) {
    e.preventDefault();
    const task = document.getElementById('task').value.trim();
    const creationDate = document.getElementById('creation-date').value || new Date().toISOString().slice(0,10);
    const nextDate = document.getElementById('next-date').value;
    const dueDate = document.getElementById('due-date').value;
    const status = document.getElementById('status').value;
    const urgent = parseInt(document.getElementById('urgent').value) || 1;
    const importance = parseInt(document.getElementById('importance').value) || 1;
    const prio = urgent * importance;
    const timeEstimation = parseInt(document.getElementById('time-estimation').value) || 0;
    const actualTime = parseInt(document.getElementById('actual-time').value) || 0;
    let category = document.getElementById('category').value.trim();
    if (category && !categories.includes(category)) {
        categories.push(category);
    }
    const coms = document.getElementById('coms').value.trim();
    const link = document.getElementById('link').value.trim();
    const comments = document.getElementById('comments').value.trim();
    const linkedTasks = document.getElementById('linked-tasks').value.trim();
    const todo = {
        id: getNextId(),
        creationDate,
        nextDate,
        dueDate,
        status,
        urgent,
        importance,
        prio,
        timeEstimation,
        actualTime,
        category,
        task,
        coms,
        link,
        comments,
        linkedTasks
    };
    todos.push(todo);
    saveTodos();
    renderForm();
    renderTodos();
    document.getElementById('todo-form').reset();
}

function init() {
    loadTodos();
    renderForm();
    renderTodos();
    document.getElementById('todo-form').addEventListener('submit', addTodo);
}

document.addEventListener('DOMContentLoaded', init);

// Password protection placeholder (to be implemented if needed)
// If you want to enable password, set a flag in localStorage and show/hide #password-section accordingly.