// assets/scripts/calendar.js
// Strings aus window.TT.i18n – keine hardcodierten deutschen Texte mehr

function t(key) {
  return window.TT?.i18n?.[key] ?? key;
}

class WeekCalendar {
  constructor() {
    this.nav           = document.querySelector('.week-nav');
    this.daysContainer = document.querySelector('.week-nav__days');
    this.calBtn        = document.querySelector('.week-nav__cal');
    this.prevBtn       = document.querySelector('.week-nav__arrow--prev');
    this.nextBtn       = document.querySelector('.week-nav__arrow--next');
    this.header        = document.querySelector('.tt-header');

    const raw       = this.nav?.dataset.activeDate;
    this.activeDate = raw ? new Date(raw + 'T00:00:00') : new Date();
    this.today      = new Date();
    this.today.setHours(0, 0, 0, 0);

    this.monthOpen  = false;
    this.monthDate  = new Date(this.activeDate);
    this.monthEl    = null;

    if (!this.nav) return;
    this.init();
  }

  get months()        { return t('months')       || []; }
  get monthsShort()   { return t('monthsShort')  || []; }
  get weekdays()      { return t('weekdays')      || []; }
  get weekdaysShort() { return t('weekdaysShort') || []; }

  init() {
    this.prevBtn?.addEventListener('click', e => { e.preventDefault(); this.navigateWeek(-1); });
    this.nextBtn?.addEventListener('click', e => { e.preventDefault(); this.navigateWeek(1); });
    this.calBtn?.addEventListener('click',  e => { e.preventDefault(); this.toggleMonth(); });

    this.daysContainer?.addEventListener('click', e => {
      const dayEl = e.target.closest('.week-nav__day');
      if (!dayEl) return;
      e.preventDefault();
      const dateStr = dayEl.dataset.date;
      if (dateStr) this.goToDate(new Date(dateStr + 'T00:00:00'));
    });
  }

  // ── Wochen-Navigation ─────────────────────────────────────────────────────

  navigateWeek(direction) {
    const slideOut = direction > 0 ? 'slide-out-left' : 'slide-out-right';
    const slideIn  = direction > 0 ? 'slide-in-right' : 'slide-in-left';

    this.daysContainer.classList.add(slideOut);

    setTimeout(() => {
      const newDate = new Date(this.activeDate);
      newDate.setDate(newDate.getDate() + direction * 7);
      this.activeDate = newDate;
      this.renderWeekDays();
      this.updateHeaderMeta();

      this.daysContainer.classList.remove(slideOut);
      this.daysContainer.classList.add(slideIn);
      requestAnimationFrame(() => requestAnimationFrame(() => {
        this.daysContainer.classList.remove(slideIn);
      }));

      window.history.pushState({}, '', `/week/${this.formatDate(this.getMonday(this.activeDate))}`);
      window.entryManager?.loadEntriesForDate(this.formatDate(this.activeDate));
    }, 180);
  }

  renderWeekDays() {
    const monday = this.getMonday(this.activeDate);
    this.daysContainer.innerHTML = '';

    for (let i = 0; i < 7; i++) {
      const d        = new Date(monday);
      d.setDate(d.getDate() + i);
      const isActive = this.isSameDay(d, this.activeDate);
      const isToday  = this.isSameDay(d, this.today);

      // Führungsnull: padStart(2, '0')
      const dayNum     = String(d.getDate()).padStart(2, '0');
      const monthShort = this.monthsShort[d.getMonth()] ?? '';

      const a        = document.createElement('a');
      a.href         = `/week/${this.formatDate(d)}`;
      a.className    = 'week-nav__day'
        + (isActive ? ' week-nav__day--active' : '')
        + (isToday  ? ' week-nav__day--today'  : '');
      a.dataset.date = this.formatDate(d);
      a.innerHTML    = `
        <span class="week-nav__day-name">${this.weekdaysShort[i] ?? ''}</span>
        <span class="week-nav__day-date">${dayNum}. ${monthShort}</span>
      `;
      this.daysContainer.appendChild(a);
    }
  }

  goToDate(date) {
    this.activeDate = date;
    this.renderWeekDays();
    this.updateHeaderMeta();
    window.history.pushState({}, '', `/week/${this.formatDate(date)}`);
    window.entryManager?.loadEntriesForDate(this.formatDate(date));
    if (this.monthOpen) this.closeMonth();
  }

  updateHeaderMeta() {
    const dateEl = document.querySelector('.tt-header__date');
    const kwEl   = document.querySelector('.tt-header__kw');

    if (dateEl) {
      const d         = this.activeDate;
      const day       = d.getDate();
      const month     = this.months[d.getMonth()] ?? '';
      const tomorrow  = new Date(this.today); tomorrow.setDate(this.today.getDate() + 1);
      const yesterday = new Date(this.today); yesterday.setDate(this.today.getDate() - 1);

      // JS getDay(): 0=So, 1=Mo...6=Sa → weekdays[0]=Montag, also index = getDay()-1, So=6
      const jsDay   = d.getDay();
      const isoIdx  = jsDay === 0 ? 6 : jsDay - 1;
      const weekday = this.weekdays[isoIdx] ?? '';

      let prefix;
      if      (this.isSameDay(d, this.today))    prefix = t('today');
      else if (this.isSameDay(d, tomorrow))      prefix = t('tomorrow');
      else if (this.isSameDay(d, yesterday))     prefix = t('yesterday');
      else                                       prefix = weekday;

      dateEl.textContent = `${prefix}, ${day}. ${month}`;
      document.title = `${prefix}, ${day}. ${month}`;
    }

    if (kwEl) kwEl.textContent = `${t('weekLabel')} ${this.getWeekNumber(this.activeDate)}`;
  }

  // ── Monats-Ansicht ────────────────────────────────────────────────────────

  toggleMonth() { this.monthOpen ? this.closeMonth() : this.openMonth(); }

  openMonth() {
    this.monthOpen = true;
    this.monthDate = new Date(this.activeDate);
    this.monthEl   = document.createElement('div');
    this.monthEl.className = 'month-calendar month-calendar--hidden';
    this.header.appendChild(this.monthEl);
    this.renderMonthGrid();
    requestAnimationFrame(() => requestAnimationFrame(() => {
      this.monthEl.classList.remove('month-calendar--hidden');
      this.monthEl.classList.add('month-calendar--visible');
    }));
    this.calBtn.classList.add('week-nav__cal--active');
  }

  closeMonth() {
    if (!this.monthEl) return;
    this.monthEl.classList.remove('month-calendar--visible');
    this.monthEl.classList.add('month-calendar--hidden');
    setTimeout(() => { this.monthEl?.remove(); this.monthEl = null; }, 280);
    this.monthOpen = false;
    this.calBtn.classList.remove('week-nav__cal--active');
  }

  renderMonthGrid() {
    if (!this.monthEl) return;

    const year  = this.monthDate.getFullYear();
    const month = this.monthDate.getMonth();

    const firstDay    = new Date(year, month, 1);
    let startDow      = firstDay.getDay();
    startDow          = startDow === 0 ? 6 : startDow - 1;
    const daysInMonth = new Date(year, month + 1, 0).getDate();
    const daysInPrev  = new Date(year, month, 0).getDate();

    let html = `
      <div class="month-calendar__header">
        <button class="month-calendar__arrow month-nav-prev" title="${t('prevMonth')}">
          <svg viewBox="0 0 8 14" fill="none"><path d="M7 1L1 7L7 13" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"/></svg>
        </button>
        <span class="month-calendar__title">${this.months[month] ?? ''} ${year}</span>
        <button class="month-calendar__arrow month-nav-next" title="${t('nextMonth')}">
          <svg viewBox="0 0 8 14" fill="none"><path d="M1 1L7 7L1 13" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"/></svg>
        </button>
        <button class="month-calendar__close week-nav__cal" title="${t('monthView')}">
          <svg viewBox="0 0 18 18" fill="none">
            <rect x="1" y="3" width="16" height="14" rx="2" stroke="currentColor" stroke-width="1.5"/>
            <path d="M1 7h16" stroke="currentColor" stroke-width="1.5"/>
            <path d="M5 1v4M13 1v4" stroke="currentColor" stroke-width="1.5" stroke-linecap="round"/>
            <rect x="4" y="10" width="2" height="2" rx="0.5" fill="currentColor"/>
            <rect x="8" y="10" width="2" height="2" rx="0.5" fill="currentColor"/>
            <rect x="12" y="10" width="2" height="2" rx="0.5" fill="currentColor"/>
          </svg>
        </button>
      </div>
      <div class="month-calendar__grid">
        <div class="month-calendar__weekdays">
          ${this.weekdaysShort.map(d => `<span>${d}</span>`).join('')}
        </div>
        <div class="month-calendar__days">`;

    for (let i = startDow - 1; i >= 0; i--)
      html += `<span class="month-day month-day--other">${daysInPrev - i}</span>`;

    for (let d = 1; d <= daysInMonth; d++) {
      const date    = new Date(year, month, d);
      const isToday = this.isSameDay(date, this.today);
      const isActive= this.isSameDay(date, this.activeDate);
      const cls     = 'month-day'
        + (isToday  ? ' month-day--today'  : '')
        + (isActive ? ' month-day--active' : '');
      html += `<span class="${cls}" data-date="${this.formatDate(date)}">${d}</span>`;
    }

    const totalCells = Math.ceil((startDow + daysInMonth) / 7) * 7;
    for (let d = 1; d <= totalCells - startDow - daysInMonth; d++)
      html += `<span class="month-day month-day--other">${d}</span>`;

    html += `</div></div>`;
    this.monthEl.innerHTML = html;

    this.monthEl.querySelector('.month-nav-prev')?.addEventListener('click', () => this.navigateMonth(-1));
    this.monthEl.querySelector('.month-nav-next')?.addEventListener('click', () => this.navigateMonth(1));
    this.monthEl.querySelector('.month-calendar__close')?.addEventListener('click', () => this.closeMonth());
    this.monthEl.querySelectorAll('.month-day[data-date]').forEach(el => {
      el.addEventListener('click', () => this.goToDate(new Date(el.dataset.date + 'T00:00:00')));
    });
  }

  navigateMonth(direction) {
    const grid = this.monthEl?.querySelector('.month-calendar__grid');
    if (!grid) return;
    const slideOut = direction > 0 ? 'slide-out-left' : 'slide-out-right';
    grid.classList.add(slideOut);
    setTimeout(() => {
      this.monthDate.setMonth(this.monthDate.getMonth() + direction);
      this.renderMonthGrid();
    }, 160);
  }

  // ── Hilfsfunktionen ───────────────────────────────────────────────────────

  getMonday(date) {
    const d   = new Date(date);
    const day = d.getDay();
    d.setDate(d.getDate() - day + (day === 0 ? -6 : 1));
    d.setHours(0, 0, 0, 0);
    return d;
  }

  isSameDay(a, b) {
    return a.getFullYear() === b.getFullYear()
        && a.getMonth()    === b.getMonth()
        && a.getDate()     === b.getDate();
  }

  formatDate(date) {
    const y = date.getFullYear();
    const m = String(date.getMonth() + 1).padStart(2, '0');
    const d = String(date.getDate()).padStart(2, '0');
    return `${y}-${m}-${d}`;
  }

  getWeekNumber(date) {
    const d = new Date(Date.UTC(date.getFullYear(), date.getMonth(), date.getDate()));
    d.setUTCDate(d.getUTCDate() + 4 - (d.getUTCDay() || 7));
    const yearStart = new Date(Date.UTC(d.getUTCFullYear(), 0, 1));
    return Math.ceil((((d - yearStart) / 86400000) + 1) / 7);
  }
}

document.addEventListener('DOMContentLoaded', () => { new WeekCalendar(); });