const { renderView } = require('../../view');

function formatDateTime(value) {
  if (!value) {
    return '';
  }
  const date = new Date(value);
  if (Number.isNaN(date.getTime())) {
    return '';
  }
  const year = date.getFullYear();
  const month = String(date.getMonth() + 1).padStart(2, '0');
  const day = String(date.getDate()).padStart(2, '0');
  const hours = String(date.getHours()).padStart(2, '0');
  const minutes = String(date.getMinutes()).padStart(2, '0');
  return `${year}-${month}-${day} ${hours}:${minutes}`;
}

function formatTime(value) {
  return value ? String(value).slice(0, 5) : '';
}

function formatDays(daysJson) {
  const dayNames = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'];
  let days = [];
  if (Array.isArray(daysJson)) {
    days = daysJson;
  } else if (daysJson) {
    try {
      const parsed = JSON.parse(daysJson);
      days = Array.isArray(parsed) ? parsed : [];
    } catch (_error) {
      days = [];
    }
  }
  return days.map((day) => dayNames[Number(day)] || '').filter(Boolean).join(', ');
}

function scheduleSummary(item) {
  const mode = String(item.schedule_mode || 'always');
  if (mode === 'dates') {
    const start = formatDateTime(item.schedule_start_datetime);
    const end = formatDateTime(item.schedule_end_datetime);
    return start && end ? `Dates: ${start} to ${end}` : 'Dates: not set';
  }
  if (mode === 'times') {
    const days = formatDays(item.schedule_days_json);
    const start = formatTime(item.schedule_start_time);
    const end = formatTime(item.schedule_end_time);
    return days && start && end ? `Times: ${days} ${start}-${end}` : 'Times: not set';
  }
  return 'Always visible';
}

function getCanvasSignature(width, height) {
  const normalizedWidth = Number(width);
  const normalizedHeight = Number(height);
  if (!Number.isFinite(normalizedWidth) || !Number.isFinite(normalizedHeight)) {
    return null;
  }
  return normalizedWidth + 'x' + normalizedHeight;
}

module.exports = function renderPlaylistEditPage(playlist, data, message, currentUser) {
  const playlistSlides = (data.playlistSlides || [])
    .filter((item) => item.playlist_id === playlist.id)
    .sort((a, b) => {
      if (a.position !== b.position) {
        return a.position - b.position;
      }
      return a.id - b.id;
    })
    .map((item, index, items) => Object.assign({}, item, {
      displayOrder: index + 1,
      isFirst: index === 0,
      isLast: index === items.length - 1,
      canvasSignature: getCanvasSignature(item.canvas_width, item.canvas_height) || '',
      scheduleSummary: scheduleSummary(item)
    }));
  const assignedSlideIds = new Set(playlistSlides.map((item) => item.slide_id));
  const playlistCanvasSignatures = Array.from(new Set(playlistSlides.map((item) => getCanvasSignature(item.canvas_width, item.canvas_height)).filter(Boolean)));
  const playlistCanvasSignature = playlistCanvasSignatures.length === 1 ? playlistCanvasSignatures[0] : null;
  const playlistCanvasMismatch = playlistCanvasSignatures.length > 1;
  const selectableSlides = (data.slides || []).filter((slide) => {
    if (playlistCanvasMismatch) {
      return false;
    }
    if (!playlistCanvasSignature) {
      return true;
    }
    return getCanvasSignature(slide.canvas_width, slide.canvas_height) === playlistCanvasSignature;
  }).map((slide) => Object.assign({}, slide, {
    canvasSignature: getCanvasSignature(slide.canvas_width, slide.canvas_height) || '',
    isAssigned: assignedSlideIds.has(slide.id)
  }));
  const hasAddableSlides = selectableSlides.some((slide) => !slide.isAssigned);

  return renderView('playlists/edit', {
    title: 'Edit playlist',
    active: 'playlists',
    message: message,
    currentUser: currentUser || null,
    playlist: playlist,
    playlistFadeBetweenSlides: Boolean(playlist.fade_between_slides),
    playlistSlides: playlistSlides,
    slides: data.slides || [],
    hasSlides: (data.slides || []).length > 0,
    hasSelectableSlides: selectableSlides.length > 0,
    hasAddableSlides: hasAddableSlides,
    selectableSlides: selectableSlides,
    playlistCanvasSignature: playlistCanvasSignature,
    playlistCanvasMismatch: playlistCanvasMismatch,
    scripts: ['js/vendor/sortable.min.js', 'js/playlists/playlist-schedule.js']
  });
};