// public/js/galleryUtils.js
// Ordinamento, filtri, raggruppamento e formattazione.

(() => {
  "use strict";

  function sortByDate(items, direction = "desc") {
    return items.slice().sort((a, b) => {
      const da = a?.taken_at ? new Date(a.taken_at) : 0;
      const db = b?.taken_at ? new Date(b.taken_at) : 0;
      return direction === "asc" ? da - db : db - da;
    });
  }

  function applyFilters(items) {
    if (window.state?.mode === "activities") return items;

    const filter = window.currentFilter;
    if (!filter) return items;

    switch (filter) {
      case "folder":
        return items.filter(item => item.cartella);
      case "location":
        return items.filter(item => item?.gps?.lat && item?.gps?.lng);
      case "type":
        return items.filter(item => item?.mime_type?.startsWith("image/"));
      default:
        return items;
    }
  }

  function formatDay(date) {
    return date.toLocaleDateString("it-IT", {
      weekday: "long",
      day: "numeric",
      month: "long"
    });
  }

  function formatMonth(date) {
    return date.toLocaleDateString("it-IT", {
      month: "long",
      year: "numeric"
    });
  }

  function groupByDate(items, mode = "auto") {
    const sections = [];
    const sectionMap = new Map();
    const now = new Date();

    function getLabel(item) {
      const date = item?.taken_at ? new Date(item.taken_at) : null;
      if (!date || Number.isNaN(date.getTime())) return "Senza data";

      const diffDays = Math.floor((now - date) / 86400000);

      if (mode === "day") return formatDay(date);
      if (mode === "month") return formatMonth(date);
      if (mode === "year") return String(date.getFullYear());

      if (diffDays === 0) return "Oggi";
      if (diffDays === 1) return "Ieri";
      if (diffDays <= 7) return "Questa settimana";
      if (diffDays <= 14) return "La settimana scorsa";
      if (diffDays <= 30) return "Questo mese";
      if (diffDays <= 60) return "Mese scorso";
      if (date.getFullYear() === now.getFullYear()) return formatMonth(date);
      return String(date.getFullYear());
    }

    for (const item of items) {
      const label = getLabel(item);
      let section = sectionMap.get(label);

      if (!section) {
        section = { label, items: [] };
        sectionMap.set(label, section);
        sections.push(section);
      }

      section.items.push(item);
    }

    return sections;
  }

  function escapeHtml(value) {
    return String(value ?? "")
      .replaceAll("&", "&amp;")
      .replaceAll("<", "&lt;")
      .replaceAll(">", "&gt;")
      .replaceAll('"', "&quot;")
      .replaceAll("'", "&#039;");
  }

  function formatDurationShort(ms) {
    const totalSec = Math.round(ms / 1000);
    const hours = Math.floor(totalSec / 3600);
    const minutes = Math.floor((totalSec % 3600) / 60);
    return hours > 0 ? `${hours}h ${minutes}m` : `${minutes}m`;
  }

  function formatActivityMeta(item) {
    const parts = [];

    if (item.sport) parts.push(item.sport);
    if (Number.isFinite(Number(item.distance_meters))) {
      parts.push(`${(Number(item.distance_meters) / 1000).toFixed(1)} km`);
    }
    if (Number.isFinite(Number(item.duration_millis))) {
      parts.push(formatDurationShort(Number(item.duration_millis)));
    }

    return parts.join(" · ");
  }

  window.GalleryUtils = Object.freeze({
    sortByDate,
    applyFilters,
    groupByDate,
    formatDay,
    formatMonth,
    escapeHtml,
    formatDurationShort,
    formatActivityMeta
  });

  // Compatibilità con gli script esistenti.
  window.sortByDate = sortByDate;
  window.applyFilters = applyFilters;
  window.groupByDate = groupByDate;
})();