/**
 * Modul: Dashboard
 * Zweck: Startseite mit Begrüßung, Terminen, Aufgaben, Essen, Notizen und FAB
 * Abhängigkeiten: /api.js
 */

import { api } from '/api.js';

// --------------------------------------------------------
// Hilfsfunktionen
// --------------------------------------------------------

function greeting(displayName) {
  const h = new Date().getHours();
  const tageszeit = h < 12 ? 'Morgen' : h < 18 ? 'Tag' : 'Abend';
  return `Guten ${tageszeit}, ${displayName}`;
}

function formatDate(date = new Date()) {
  return date.toLocaleDateString('de-DE', {
    weekday: 'long', year: 'numeric', month: 'long', day: 'numeric',
  });
}

function formatDateTime(isoString) {
  if (!isoString) return '';
  const d = new Date(isoString);
  const today = new Date();
  const tomorrow = new Date(today);
  tomorrow.setDate(today.getDate() + 1);

  const dateStr = d.toDateString() === today.toDateString()
    ? 'Heute'
    : d.toDateString() === tomorrow.toDateString()
    ? 'Morgen'
    : d.toLocaleDateString('de-DE', { day: '2-digit', month: '2-digit' });

  const timeStr = d.toLocaleTimeString('de-DE', { hour: '2-digit', minute: '2-digit' });
  return `${dateStr}, ${timeStr} Uhr`;
}

function formatDueDate(dateStr) {
  if (!dateStr) return null;
  const due = new Date(dateStr);
  const now = new Date();
  const diffMs = due - now;
  const diffH = diffMs / (1000 * 60 * 60);

  if (diffMs < 0) return { text: 'Überfällig', overdue: true };
  if (diffH < 24) return { text: 'Heute fällig', overdue: false };
  if (diffH < 48) return { text: 'Morgen fällig', overdue: false };
  return {
    text: due.toLocaleDateString('de-DE', { day: '2-digit', month: '2-digit' }),
    overdue: false,
  };
}

const MEAL_LABELS = {
  breakfast: 'Frühstück',
  lunch:     'Mittagessen',
  dinner:    'Abendessen',
  snack:     'Snack',
};

function initials(name = '') {
  return name.split(' ').map((w) => w[0]).join('').slice(0, 2).toUpperCase();
}

// --------------------------------------------------------
// Skeleton
// --------------------------------------------------------

function skeletonWidget(lines = 3) {
  const lineHtml = Array.from({ length: lines }, (_, i) => `
    <div class="skeleton skeleton-line ${i % 2 === 0 ? 'skeleton-line--full' : 'skeleton-line--medium'}"
         style="margin-bottom:var(--space-2)"></div>
  `).join('');
  return `
    <div class="widget-skeleton">
      <div class="skeleton skeleton-line skeleton-line--short"
           style="height:16px;margin-bottom:var(--space-4)"></div>
      ${lineHtml}
    </div>
  `;
}

// --------------------------------------------------------
// Widget-Renderer
// --------------------------------------------------------

function renderGreeting(user) {
  return `
    <div class="widget-greeting">
      <div class="widget-greeting__title">${greeting(user.display_name)}</div>
      <div class="widget-greeting__date">${formatDate()}</div>
    </div>
  `;
}

function renderUrgentTasks(tasks) {
  const header = `
    <div class="widget__header">
      <span class="widget__title">
        <i data-lucide="alert-circle" class="widget__title-icon" aria-hidden="true"></i>
        Dringende Aufgaben
      </span>
      <a href="/tasks" data-route="/tasks" class="widget__link">Alle</a>
    </div>
  `;

  if (!tasks.length) {
    return `<div class="widget">${header}
      <div class="widget__empty">Keine dringenden Aufgaben. ✓</div>
    </div>`;
  }

  const items = tasks.map((t) => {
    const due = formatDueDate(t.due_date);
    return `
      <div class="task-item" data-route="/tasks" role="button" tabindex="0"
           aria-label="Aufgabe: ${t.title}">
        <div class="task-item__priority task-item__priority--${t.priority}"></div>
        <div class="task-item__content">
          <div class="task-item__title">${t.title}</div>
          ${due ? `<div class="task-item__meta ${due.overdue ? 'task-item__meta--overdue' : ''}">${due.text}</div>` : ''}
        </div>
        ${t.assigned_color ? `
          <div class="task-item__avatar" style="background-color:${t.assigned_color}"
               title="${t.assigned_name || ''}">
            ${initials(t.assigned_name || '')}
          </div>` : ''}
      </div>
    `;
  }).join('');

  return `<div class="widget">${header}<div class="widget__body">${items}</div></div>`;
}

function renderUpcomingEvents(events) {
  const header = `
    <div class="widget__header">
      <span class="widget__title">
        <i data-lucide="calendar" class="widget__title-icon" aria-hidden="true"></i>
        Anstehende Termine
      </span>
      <a href="/calendar" data-route="/calendar" class="widget__link">Alle</a>
    </div>
  `;

  if (!events.length) {
    return `<div class="widget">${header}
      <div class="widget__empty">Keine anstehenden Termine.</div>
    </div>`;
  }

  const items = events.map((e) => `
    <div class="event-item" data-route="/calendar" role="button" tabindex="0"
         aria-label="Termin: ${e.title}">
      <div class="event-item__bar"
           style="background-color:${e.assigned_color || e.color || 'var(--color-accent)'}"></div>
      <div class="event-item__content">
        <div class="event-item__title">${e.title}</div>
        <div class="event-item__time">
          ${e.all_day ? formatDate(new Date(e.start_datetime)) : formatDateTime(e.start_datetime)}
          ${e.location ? ` · ${e.location}` : ''}
        </div>
      </div>
    </div>
  `).join('');

  return `<div class="widget">${header}<div class="widget__body">${items}</div></div>`;
}

function renderTodayMeals(meals) {
  const header = `
    <div class="widget__header">
      <span class="widget__title">
        <i data-lucide="utensils" class="widget__title-icon" aria-hidden="true"></i>
        Heute essen
      </span>
      <a href="/meals" data-route="/meals" class="widget__link">Alle</a>
    </div>
  `;

  if (!meals.length) {
    return `<div class="widget">${header}
      <div class="widget__empty">Kein Essensplan für heute.</div>
    </div>`;
  }

  const items = meals.map((m) => `
    <div class="meal-item" data-route="/meals" role="button" tabindex="0"
         aria-label="${MEAL_LABELS[m.meal_type]}: ${m.title}">
      <span class="meal-item__type-badge">${MEAL_LABELS[m.meal_type]}</span>
      <span class="meal-item__title">${m.title}</span>
    </div>
  `).join('');

  return `<div class="widget">${header}<div class="widget__body">${items}</div></div>`;
}

function renderPinnedNotes(notes) {
  const header = `
    <div class="widget__header">
      <span class="widget__title">
        <i data-lucide="pin" class="widget__title-icon" aria-hidden="true"></i>
        Pinnwand
      </span>
      <a href="/notes" data-route="/notes" class="widget__link">Alle</a>
    </div>
  `;

  if (!notes.length) {
    return `<div class="widget">${header}
      <div class="widget__empty">Keine angepinnten Notizen.</div>
    </div>`;
  }

  const items = notes.map((n) => `
    <div class="note-item" data-route="/notes" role="button" tabindex="0"
         style="background-color:${n.color}22; border-left-color:${n.color};"
         aria-label="Notiz${n.title ? ': ' + n.title : ''}">
      ${n.title ? `<div class="note-item__title">${n.title}</div>` : ''}
      <div class="note-item__content">${n.content}</div>
    </div>
  `).join('');

  return `<div class="widget">${header}<div class="widget__body">${items}</div></div>`;
}

// --------------------------------------------------------
// FAB Speed-Dial
// --------------------------------------------------------

const FAB_ACTIONS = [
  { route: '/tasks',    label: 'Aufgabe',  icon: 'check-square'   },
  { route: '/calendar', label: 'Termin',   icon: 'calendar-plus'  },
  { route: '/shopping', label: 'Einkauf',  icon: 'shopping-cart'  },
  { route: '/notes',    label: 'Notiz',    icon: 'sticky-note'    },
];

function renderFab() {
  const actionsHtml = FAB_ACTIONS.map((a) => `
    <div class="fab-action" data-route="${a.route}" role="button" tabindex="-1"
         aria-label="${a.label} hinzufügen">
      <span class="fab-action__label">${a.label}</span>
      <button class="fab-action__btn" tabindex="-1" aria-hidden="true">
        <i data-lucide="${a.icon}" aria-hidden="true"></i>
      </button>
    </div>
  `).join('');

  return `
    <div class="fab-container" id="fab-container">
      <button class="fab-main" id="fab-main" aria-label="Schnellaktionen" aria-expanded="false">
        <i data-lucide="plus" aria-hidden="true"></i>
      </button>
      <div class="fab-actions" id="fab-actions" aria-hidden="true">
        ${actionsHtml}
      </div>
    </div>
  `;
}

function initFab(container) {
  const fabMain    = container.querySelector('#fab-main');
  const fabActions = container.querySelector('#fab-actions');
  if (!fabMain) return;

  let open = false;

  function toggleFab(force) {
    open = force !== undefined ? force : !open;
    fabMain.classList.toggle('fab-main--open', open);
    fabMain.setAttribute('aria-expanded', String(open));
    fabActions.classList.toggle('fab-actions--visible', open);
    fabActions.setAttribute('aria-hidden', String(!open));
    fabActions.querySelectorAll('[role="button"]').forEach((el) => {
      el.tabIndex = open ? 0 : -1;
    });
    if (window.lucide) window.lucide.createIcons();
  }

  fabMain.addEventListener('click', (e) => { e.stopPropagation(); toggleFab(); });

  fabActions.querySelectorAll('[data-route]').forEach((el) => {
    const go = () => { toggleFab(false); window.oikos.navigate(el.dataset.route); };
    el.addEventListener('click', go);
    el.addEventListener('keydown', (e) => {
      if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); go(); }
    });
  });

  document.addEventListener('click', () => { if (open) toggleFab(false); });
}

// --------------------------------------------------------
// Navigations-Links verdrahten
// --------------------------------------------------------

function wireLinks(container) {
  container.querySelectorAll('[data-route]').forEach((el) => {
    if (el.id === 'fab-main' || el.closest('#fab-actions')) return; // FAB separat
    const go = () => window.oikos.navigate(el.dataset.route);
    if (el.tagName === 'A') {
      el.addEventListener('click', (e) => { e.preventDefault(); go(); });
    } else {
      el.addEventListener('click', go);
      el.addEventListener('keydown', (e) => {
        if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); go(); }
      });
    }
  });
}

// --------------------------------------------------------
// Haupt-Render
// --------------------------------------------------------

export async function render(container, { user }) {
  // Sofort Skeleton
  container.innerHTML = `
    <div class="dashboard">
      <div class="dashboard__grid">
        <div class="widget-greeting" style="grid-column:1/-1">
          <div class="widget-greeting__title">${greeting(user.display_name)}</div>
          <div class="widget-greeting__date">${formatDate()}</div>
        </div>
        ${skeletonWidget(3)}
        ${skeletonWidget(3)}
        ${skeletonWidget(2)}
        ${skeletonWidget(3)}
      </div>
    </div>
    ${renderFab()}
  `;
  initFab(container);

  // Daten laden
  let data = { upcomingEvents: [], urgentTasks: [], todayMeals: [], pinnedNotes: [] };
  try {
    data = await api.get('/dashboard');
  } catch (err) {
    console.error('[Dashboard] Ladefehler:', err.message);
    window.oikos?.showToast('Dashboard konnte nicht vollständig geladen werden.', 'warning');
  }

  // Widgets rendern
  container.innerHTML = `
    <div class="dashboard">
      <div class="dashboard__grid">
        ${renderGreeting(user)}
        ${renderUrgentTasks(data.urgentTasks ?? [])}
        ${renderUpcomingEvents(data.upcomingEvents ?? [])}
        ${renderTodayMeals(data.todayMeals ?? [])}
        ${renderPinnedNotes(data.pinnedNotes ?? [])}
      </div>
    </div>
    ${renderFab()}
  `;

  wireLinks(container);
  initFab(container);
  if (window.lucide) window.lucide.createIcons();
}