document.addEventListener("DOMContentLoaded", () => {
  document.addEventListener("contextmenu", e => e.preventDefault());
  // ==========================================================================
  //  RIFERIMENTI DOM
  // ==========================================================================
  const folderEl = document.getElementById("folder");
  const contextMenuEl = document.getElementById("context-menu");

  // ==========================================================================
  //  STATO GLOBALE
  // ==========================================================================
  let appsData = [];
  let appsOrder = [];
  let editMode = false;

  // Zoom
  let zoomLevel;
  let zoomMax;
  let initialPinchDistance = null;
  let lastTapTime = 0;
  let zoomAnimFrame = null;

  // Long‑press / drag
  let longPressTimer = null;
  let longPressTarget = null;
  let contextMenuTargetId = null;

  let draggingIcon = null;
  let draggingId = null;
  let dragOffsetX = 0;
  let dragOffsetY = 0;
  let dragStartX = 0;
  let dragStartY = 0;

  // ==========================================================================
  //  CARICAMENTO APPS
  // ==========================================================================
  function loadOrder() {
    try {
      const val = localStorage.getItem("appsOrder");
      if (!val) return null;
      const parsed = JSON.parse(val);
      return Array.isArray(parsed) ? parsed : null;
    } catch {
      return null;
    }
  }

  function saveOrder() {
    localStorage.setItem("appsOrder", JSON.stringify(appsOrder));
  }

  function renderApps() {
    folderEl.innerHTML = "";

    appsOrder.forEach(id => {
      const app = appsData.find(a => a.id === id);
      if (!app) return;

      const div = document.createElement("div");
      div.className = "app-icon";
      div.dataset.id = app.id;

      div.innerHTML = `
        <img src="${app.icon}" alt="${app.name}">
        <span>${app.name}</span>
      `;

      div.addEventListener("click", () => {
        if (!editMode) window.open(app.url, "_blank", "noopener");
      });

      folderEl.appendChild(div);
    });
  }

  async function loadApps() {
    const apps = await fetch("apps.json").then(r => r.json());

    appsData = apps.map((app, i) => ({
      id: app.id || `app-${i}`,
      name: app.name,
      url: app.url,
      icon: app.icon
    }));

    const stored = loadOrder();
    if (stored) {
      appsOrder = stored.filter(id => appsData.some(a => a.id === id));
      appsData.forEach(a => {
        if (!appsOrder.includes(a.id)) appsOrder.push(a.id);
      });
    } else {
      appsOrder = appsData.map(a => a.id);
    }

    renderApps();
  }

  // ==========================================================================
  //  ZOOM STILE IPHONE (PINCH ELASTICO)
  // ==========================================================================
  function computeDynamicMaxZoom() {
    return Math.min(window.innerWidth / 85, 4.0);
  }

  function loadInitialZoom() {
    const v = parseFloat(localStorage.getItem("zoomLevel"));
    if (!isFinite(v) || v <= 0) return 1;
    return Math.min(Math.max(v, 0.5), computeDynamicMaxZoom());
  }

  function applyZoom(z) {
    zoomLevel = (!isFinite(z) || z <= 0) ? 1 : z;
    document.documentElement.style.setProperty("--zoom", zoomLevel);
    localStorage.setItem("zoomLevel", String(zoomLevel));
  }

  function getPinchDistance(touches) {
    const [a, b] = touches;
    return Math.hypot(a.clientX - b.clientX, a.clientY - b.clientY);
  }

  function elasticEase(x) {
    return Math.sin(x * Math.PI * 0.5) * 1.05;
  }

  function initZoomHandlers() {
    zoomMax = computeDynamicMaxZoom();
    zoomLevel = loadInitialZoom();
    applyZoom(zoomLevel);

    document.addEventListener("touchmove", e => {
      if (e.touches.length === 2) e.preventDefault();
    }, { passive: false });

    document.addEventListener("touchstart", e => {
      if (e.touches.length === 2) {
        initialPinchDistance = getPinchDistance(e.touches);
        if (zoomAnimFrame) cancelAnimationFrame(zoomAnimFrame);
      }

      const now = Date.now();
      if (e.touches.length === 1 && now - lastTapTime < 300) {
        zoomMax = computeDynamicMaxZoom();
        applyZoom(Math.min(zoomLevel * 1.15, zoomMax));
      }
      lastTapTime = now;
    });

    document.addEventListener("touchmove", e => {
      if (e.touches.length === 2 && initialPinchDistance) {
        const newDist = getPinchDistance(e.touches);
        const scale = newDist / initialPinchDistance;

        let newZoom = zoomLevel * scale;
        zoomMax = computeDynamicMaxZoom();

        if (newZoom > zoomMax) newZoom = zoomMax + (newZoom - zoomMax) * 0.25;
        if (newZoom < 0.5) newZoom = 0.5 - (0.5 - newZoom) * 0.25;

        applyZoom(newZoom);
        initialPinchDistance = newDist;
        e.preventDefault();
      }
    }, { passive: false });

    document.addEventListener("touchend", e => {
      if (e.touches.length < 2 && initialPinchDistance) {
        initialPinchDistance = null;

        zoomMax = computeDynamicMaxZoom();
        const target = Math.min(Math.max(zoomLevel, 0.5), zoomMax);
        const start = zoomLevel;
        const duration = 250;
        const startTime = performance.now();

        function animate(t) {
          const p = Math.min((t - startTime) / duration, 1);
          const eased = start + (target - start) * elasticEase(p);
          applyZoom(eased);
          if (p < 1) zoomAnimFrame = requestAnimationFrame(animate);
        }

        zoomAnimFrame = requestAnimationFrame(animate);
      }
    });
  }

// ==========================================================================
  //  EDIT MODE + MENU CONTESTUALE + WIGGLE
  // ==========================================================================
  function enterEditMode() {
    editMode = true;
    document.body.classList.add("edit-mode");
  }

  function exitEditMode() {
    editMode = false;
    document.body.classList.remove("edit-mode");
    hideContextMenu();
  }

  function showContextMenuFor(id, x, y) {
    contextMenuTargetId = id;
    contextMenuEl.style.left = `${x}px`;
    contextMenuEl.style.top = `${y}px`;
    contextMenuEl.classList.remove("hidden");
  }

  function hideContextMenu() {
    contextMenuEl.classList.add("hidden");
    contextMenuTargetId = null;
  }

  // ==========================================================================
  //  LONG PRESS → SOLO ENTRA IN WIGGLE MODE (NON APRE PIÙ IL MENÙ)
  // ==========================================================================
function initLongPressHandlers() {
  document.addEventListener("touchstart", e => {
    if (e.touches.length !== 1) return;

    const touch = e.touches[0];
    const icon = touch.target.closest(".app-icon");

    // Se premi su un'icona
    if (icon) {
      longPressTarget = icon;

      longPressTimer = setTimeout(() => {

        // 1️⃣ Se NON siamo in wiggle mode → entra in wiggle mode
        if (!editMode) {
          enterEditMode();
          if (navigator.vibrate) navigator.vibrate(10);
          return;
        }

        // 2️⃣ Se SIAMO in wiggle mode → apri il menù contestuale
        const r = icon.getBoundingClientRect();
        showContextMenuFor(
          icon.dataset.id,
          r.left + r.width / 2,
          r.top + r.height
        );
        if (navigator.vibrate) navigator.vibrate(10);

      }, 350);

      return;
    }

    // Se premi FUORI dalle icone
    longPressTimer = setTimeout(() => {
      if (editMode) exitEditMode();
    }, 350);

  }, { passive: true });

  document.addEventListener("touchmove", e => {
    if (!longPressTimer) return;

    const touch = e.touches[0];
    const dx = touch.clientX - (longPressTarget?.getBoundingClientRect().left ?? touch.clientX);
    const dy = touch.clientY - (longPressTarget?.getBoundingClientRect().top ?? touch.clientY);

    if (Math.hypot(dx, dy) > 15) {
      clearTimeout(longPressTimer);
      longPressTimer = null;
      longPressTarget = null;
    }
  }, { passive: true });

  document.addEventListener("touchend", () => {
    if (longPressTimer) {
      clearTimeout(longPressTimer);
      longPressTimer = null;
      longPressTarget = null;
    }
  }, { passive: true });
}

  // ==========================================================================
  //  DOUBLE TAP (MOBILE) + DOUBLE CLICK (DESKTOP) → APRE IL MENÙ
  // ==========================================================================
/*  function initDoubleTapContextMenu() {
    let lastTap = 0;

    // MOBILE double tap
    folderEl.addEventListener("touchend", e => {
      if (!editMode) return;

      const icon = e.target.closest(".app-icon");
      if (!icon) return;

      const now = Date.now();
      if (now - lastTap < 300) {
        const r = icon.getBoundingClientRect();
        showContextMenuFor(
          icon.dataset.id,
          r.left + r.width / 2,
          r.top + r.height
        );
        if (navigator.vibrate) navigator.vibrate(10);
      }
      lastTap = now;
    });

    // DESKTOP double click
    folderEl.addEventListener("dblclick", e => {
      if (!editMode) return;

      const icon = e.target.closest(".app-icon");
      if (!icon) return;

      const r = icon.getBoundingClientRect();
      showContextMenuFor(
        icon.dataset.id,
        r.left + r.width / 2,
        r.top + r.height
      );
    });
  }
*/
// ==========================================================================
  //  DRAG FLUIDO STILE IPHONE CON PLACEHOLDER + FIX "SOTTO IL DITO"
  // ==========================================================================
  function startDrag(icon, touch) {
    draggingId = icon.dataset.id;

    // 1️⃣ Cattura posizione PRIMA di toccare il DOM
    const r = icon.getBoundingClientRect();
    dragOffsetX = touch.pageX - r.left;
    dragOffsetY = touch.pageY - r.top;

    // 2️⃣ Sposta SUBITO l’icona vera fuori dal flusso
    draggingIcon = icon;
    draggingIcon.classList.add("dragging");
    draggingIcon.style.position = "fixed";
    draggingIcon.style.left = `${r.left}px`;
    draggingIcon.style.top = `${r.top}px`;
    draggingIcon.style.width = `${r.width}px`;
    draggingIcon.style.height = `${r.height}px`;
    draggingIcon.style.zIndex = "1000";
    draggingIcon.style.pointerEvents = "none";
//    draggingIcon.style.transform = "translate3d(0,0,0)`;
    draggingIcon.style.transform = "translate3d(0,0,0)";
    // 3️⃣ SOLO ORA crea il placeholder invisibile
    const placeholder = icon.cloneNode(true);
    placeholder.classList.add("placeholder");
    placeholder.style.visibility = "hidden";
    icon.parentNode.insertBefore(placeholder, icon);

    hideContextMenu();
  }

  function updateDragPosition(touch) {
    if (!draggingIcon) return;

    // Mantieni l’icona ESATTAMENTE sotto il dito
    const x = touch.pageX - dragOffsetX;
    const y = touch.pageY - dragOffsetY;

    draggingIcon.style.left = `${x}px`;
    draggingIcon.style.top = `${y}px`;

    // Trova icona sotto il dito
    const elem = document.elementFromPoint(touch.clientX, touch.clientY);
    const targetIcon = elem && elem.closest(".app-icon:not(.dragging):not(.placeholder)");
    if (!targetIcon) return;

    const from = appsOrder.indexOf(draggingId);
    const to = appsOrder.indexOf(targetIcon.dataset.id);
    if (from === -1 || to === -1 || from === to) return;

    // Riordino
    appsOrder.splice(from, 1);
    appsOrder.splice(to, 0, draggingId);
    saveOrder();
    //renderApps();

    // Ricrea placeholder nella nuova posizione
    /*const oldPlaceholder = folderEl.querySelector(".app-icon.placeholder");
    if (oldPlaceholder) oldPlaceholder.remove();

    const newPos = folderEl.querySelector(`.app-icon[data-id="${draggingId}"]`);
    if (newPos) {
      const clone = newPos.cloneNode(true);
      clone.classList.add("placeholder");
      clone.style.visibility = "hidden";
      newPos.parentNode.insertBefore(clone, newPos);
    }*/
  }

  // ==========================================================================
  //  DROP PRECISO NELLA CELLA CORRETTA
  // ==========================================================================
  function endDrag() {
    if (!draggingIcon) return;

    const icon = draggingIcon;
    draggingIcon = null;

    // 1️⃣ Rimuovi placeholder
    const placeholder = folderEl.querySelector(".app-icon.placeholder");
    if (placeholder) placeholder.remove();

    // 2️⃣ Calcola la cella target sotto il dito
    const dropX = parseFloat(icon.style.left) + icon.offsetWidth / 2;
    const dropY = parseFloat(icon.style.top) + icon.offsetHeight / 2;

    const elem = document.elementFromPoint(dropX, dropY);
    const targetIcon = elem && elem.closest(".app-icon:not(.dragging)");

    if (targetIcon) {
      const from = appsOrder.indexOf(icon.dataset.id);
      const to = appsOrder.indexOf(targetIcon.dataset.id);

      if (from !== -1 && to !== -1 && from !== to) {
        appsOrder.splice(from, 1);
        appsOrder.splice(to, 0, icon.dataset.id);
        saveOrder();
      }
    }

    // 3️⃣ Ripristina icona
    icon.classList.remove("dragging");
    icon.style.position = "";
    icon.style.left = "";
    icon.style.top = "";
    icon.style.width = "";
    icon.style.height = "";
    icon.style.zIndex = "";
    icon.style.pointerEvents = "";
    icon.style.transform = "";

    // 4️⃣ Re-render finale
    renderApps();
  }

  function initDragHandlers() {
    document.addEventListener("touchstart", e => {
      if (!editMode) return;
      if (e.touches.length !== 1) return;

      const touch = e.touches[0];
      const icon = touch.target.closest(".app-icon");
      if (!icon) return;

      if (contextMenuTargetId) return;

      dragStartX = touch.clientX;
      dragStartY = touch.clientY;
      draggingIcon = null;
      draggingId = null;
    }, { passive: true });

    document.addEventListener("touchmove", e => {
      if (!editMode) return;
      if (e.touches.length !== 1) return;

      const touch = e.touches[0];

      if (!draggingIcon) {
        const dx = touch.clientX - dragStartX;
        const dy = touch.clientY - dragStartY;
        if (Math.hypot(dx, dy) > 10) {
          const icon = touch.target.closest(".app-icon");
          if (icon) startDrag(icon, touch);
        }
      } else {
        updateDragPosition(touch);
        e.preventDefault();
      }
    }, { passive: false });

    document.addEventListener("touchend", e => {
      if (!editMode) return;
      if (draggingIcon && e.touches.length === 0) {
        endDrag();
      }
    }, { passive: true });
  }

  // ==========================================================================
  //  MENU CONTESTUALE: AZIONI
  // ==========================================================================
  function initContextMenuActions() {
    contextMenuEl.addEventListener("click", e => {
      const btn = e.target.closest("button");
      if (!btn || !contextMenuTargetId) return;

      const action = btn.dataset.action;
      const app = appsData.find(a => a.id === contextMenuTargetId);
      if (!app) return;

      if (action === "rename") {
        const nuovoNome = prompt("Nuovo nome app:", app.name);
        if (nuovoNome && nuovoNome.trim()) {
          app.name = nuovoNome.trim();
          renderApps();
          saveOrder();
        }
      }

      if (action === "change-icon") {
        const nuovaIcona = prompt("URL nuova icona:", app.icon);
        if (nuovaIcona && nuovaIcona.trim()) {
          app.icon = nuovaIcona.trim();
          renderApps();
          saveOrder();
        }
      }

      if (action === "remove") {
        if (confirm("Rimuovere questa app dalla griglia?")) {
          appsOrder = appsOrder.filter(id => id !== app.id);
          saveOrder();
          renderApps();
        }
      }

      hideContextMenu();
    });
  }

  // ==========================================================================
  //  INIT GLOBALE
  // ==========================================================================
  (async function init() {
    await loadApps();
    initZoomHandlers();
    initLongPressHandlers();          // long‑press → wiggle mode
  //  initDoubleTapContextMenu();       // double tap / double click → menù
    initDragHandlers();
    initContextMenuActions();
  })();

});