xjs/layer.js

(function (global, factory) {
  const LayerClass = factory();
  // Allow usage as `Layer({...})` or `new Layer()`
  // But Layer is a class. We can wrap it in a proxy or factory function.
  
  function LayerFactory(options) {
     if (options && typeof options === 'object') {
         return LayerClass.$(options);
     }
     return new LayerClass();
  }
  
  // Copy static methods (including non-enumerable class statics like `fire` / `$`)
  // Class static methods are non-enumerable by default, so Object.assign() would miss them.
  const copyStatic = (to, from) => {
    try {
      Object.getOwnPropertyNames(from).forEach((k) => {
        if (k === 'prototype' || k === 'name' || k === 'length') return;
        const desc = Object.getOwnPropertyDescriptor(from, k);
        if (!desc) return;
        Object.defineProperty(to, k, desc);
      });
    } catch (e) {
      // Best-effort fallback
      try { Object.assign(to, from); } catch {}
    }
  };
  copyStatic(LayerFactory, LayerClass);
  // Also copy prototype for instanceof checks if needed (though tricky with factory)
  LayerFactory.prototype = LayerClass.prototype;
  
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = LayerFactory :
    typeof define === 'function' && define.amd ? define(() => LayerFactory) :
      (global.Layer = LayerFactory);
}(this, (function () {
  'use strict';

  const PREFIX = 'layer-';
  const RING_TYPES = new Set(['success', 'error', 'warning', 'info', 'question']);
  const RING_BG_PARTS_SELECTOR = `.${PREFIX}success-circular-line-left, .${PREFIX}success-circular-line-right, .${PREFIX}success-fix`;

  const normalizeOptions = (options, text, icon) => {
    if (typeof options !== 'string') return options || {};
    const o = { title: options };
    if (text) o.text = text;
    if (icon) o.icon = icon;
    return o;
  };
  
  const el = (tag, className, text) => {
    const node = document.createElement(tag);
    if (className) node.className = className;
    if (text !== undefined) node.textContent = text;
    return node;
  };
  
  const svgEl = (tag) => document.createElementNS('http://www.w3.org/2000/svg', tag);
  
  // Ensure library CSS is loaded (xjs.css)
  // - CSS is centralized in xjs.css (no runtime <style> injection).
  // - We still auto-load it for convenience/compat, since consumers may forget the <link>.
  let _xjsCssReady = null; // Promise<void>
  const waitForStylesheet = (link) => new Promise((resolve) => {
    if (!link) return resolve();
    if (link.sheet) return resolve();
    let done = false;
    const finish = () => {
      if (done) return;
      done = true;
      resolve();
    };
    try { link.addEventListener('load', finish, { once: true }); } catch {}
    try { link.addEventListener('error', finish, { once: true }); } catch {}
    // Fallback timeout: avoid blocking forever if the load event is missed.
    setTimeout(finish, 200);
  });
  const ensureXjsCss = () => {
    try {
      if (_xjsCssReady) return _xjsCssReady;
      if (typeof document === 'undefined') return Promise.resolve();
      if (!document.head) return Promise.resolve();

      const existingLink = Array.from(document.querySelectorAll('link[rel="stylesheet"]'))
        .find((l) => /(^|\/)xjs\.css(\?|#|$)/.test((l.getAttribute('href') || '').trim()));
      if (existingLink) return (_xjsCssReady = waitForStylesheet(existingLink));

      const id = 'xjs-css';
      const existing = document.getElementById(id);
      if (existing) return (_xjsCssReady = waitForStylesheet(existing));

      const scripts = Array.from(document.getElementsByTagName('script'));
      const scriptSrc = scripts
        .map((s) => s && s.src)
        .find((src) => /(^|\/)(xjs|layer)\.js(\?|#|$)/.test(String(src || '')));

      let href = 'xjs.css';
      if (scriptSrc) {
        href = String(scriptSrc)
          .replace(/(^|\/)xjs\.js(\?|#|$)/, '$1xjs.css$2')
          .replace(/(^|\/)layer\.js(\?|#|$)/, '$1xjs.css$2');
      }

      const link = document.createElement('link');
      link.id = id;
      link.rel = 'stylesheet';
      link.href = href;
      _xjsCssReady = waitForStylesheet(link);
      document.head.appendChild(link);
      return _xjsCssReady;
    } catch {
      // ignore
      return Promise.resolve();
    }
  };

  class Layer {
    constructor() {
      this._cssReady = ensureXjsCss();
      this.params = {};
      this.dom = {};
      this.promise = null;
      this.resolve = null;
      this.reject = null;
      this._onKeydown = null;
      this._mounted = null; // { kind, originalEl, placeholder, parent, nextSibling, prevHidden, prevInlineDisplay }
      this._isClosing = false;

      // Step/flow support
      this._flowSteps = null; // Array<options>
      this._flowIndex = 0;
      this._flowValues = [];
      this._flowBase = null; // base options merged into each step
      this._flowResolved = null; // resolved merged steps
      this._flowMountedList = []; // mounted DOM records for move-mode steps
    }

    // Constructor helper when called as function: const popup = Layer({...})
    static get isProxy() { return true; }
    
    // Static entry point
    static fire(options) {
      const instance = new Layer();
      return instance._fire(options);
    }
    
    // Chainable entry point (builder-style)
    // Example:
    //   Layer.$({ title: 'Hi' }).fire().then(...)
    //   Layer.$().config({ title: 'Hi' }).fire()
    static $(options) {
      const instance = new Layer();
      if (options !== undefined) instance.config(options);
      return instance;
    }
    
    // Chainable config helper (does not render until `.fire()` is called)
    config(options = {}) {
      // Support the same shorthand as Layer.fire(title, text, icon)
      options = normalizeOptions(options, arguments[1], arguments[2]);
      this.params = { ...(this.params || {}), ...options };
      return this;
    }

    // Add a single step (chainable)
    // Usage:
    //   Layer.$().step({ title:'A', dom:'#step1' }).step({ title:'B', dom:'#step2' }).fire()
    step(options = {}) {
      if (!this._flowSteps) this._flowSteps = [];
      this._flowSteps.push(normalizeOptions(options, arguments[1], arguments[2]));
      return this;
    }

    // Add multiple steps at once (chainable)
    steps(steps = []) {
      if (!Array.isArray(steps)) return this;
      if (!this._flowSteps) this._flowSteps = [];
      steps.forEach((s) => this.step(s));
      return this;
    }

    // Convenience static helper: Layer.flow([steps], baseOptions?)
    static flow(steps = [], baseOptions = {}) {
      return Layer.$(baseOptions).steps(steps).fire();
    }
    
    // Instance entry point (chainable)
    fire(options) {
      // Flow mode: if configured via .step()/.steps(), ignore per-call options and use steps
      if (this._flowSteps && this._flowSteps.length) {
        if (options !== undefined && options !== null) {
          // allow providing base options at fire-time
          this.params = { ...(this.params || {}), ...normalizeOptions(options, arguments[1], arguments[2]) };
        }
        return this._fireFlow();
      }

      const merged = (options === undefined) ? (this.params || {}) : options;
      return this._fire(merged);
    }

    _fire(options = {}) {
      options = normalizeOptions(options, arguments[1], arguments[2]);

      this.params = {
        title: '',
        text: '',
        icon: null,
        iconSize: null, // e.g. '6em' / '72px'
        confirmButtonText: 'OK',
        cancelButtonText: 'Cancel',
        showCancelButton: false,
        confirmButtonColor: '#3085d6',
        cancelButtonColor: '#aaa',
        closeOnClickOutside: true,
        closeOnEsc: true,
        iconAnimation: true,
        popupAnimation: true,
        // Content:
        // - text: plain text
        // - html: innerHTML
        // - dom: selector / Element / <template> (preferred)
        // - content: backward compat for selector/Element OR advanced { dom, mode, clone }
        dom: null,
        domMode: 'move', // 'move' (default) | 'clone'
        // Hook for confirming (also used in flow steps)
        // Return false to prevent close / next.
        // Return a value to be attached as `value`.
        // May return Promise.
        preConfirm: null,
        ...options
      };

      this.promise = new Promise((resolve, reject) => {
        this.resolve = resolve;
        this.reject = reject;
      });

      this._render();
      return this.promise;
    }

    _fireFlow() {
      this._flowIndex = 0;
      this._flowValues = [];
      // In flow mode:
      // - keep iconAnimation off by default (avoids jitter)
      // - BUT allow popupAnimation by default so the first step has the same entrance feel
      const base = { ...(this.params || {}) };
      if (!('popupAnimation' in base)) base.popupAnimation = true;
      if (!('iconAnimation' in base)) base.iconAnimation = false;
      this._flowBase = base;

      this.promise = new Promise((resolve, reject) => {
        this.resolve = resolve;
        this.reject = reject;
      });

      this._flowResolved = (this._flowSteps || []).map((_, i) => this._getFlowStepOptions(i));
      const first = this._flowResolved[0] || this._getFlowStepOptions(0);
      this.params = first;
      this._render({ flow: true });
      return this.promise;
    }

    static _getXjs() {
      // Prefer xjs, fallback to animal (compat)
      const g = (typeof window !== 'undefined') ? window : (typeof globalThis !== 'undefined' ? globalThis : null);
      if (!g) return null;
      const x = g.xjs || g.animal;
      return (typeof x === 'function') ? x : null;
    }

    _render(meta = null) {
      // Remove existing if any (but first, try to restore any mounted DOM from the previous instance)
      const existing = document.querySelector(`.${PREFIX}overlay`);
      if (existing) {
        try {
          const prev = existing._layerInstance;
          if (prev && typeof prev._forceDestroy === 'function') prev._forceDestroy('replace');
        } catch {}
        try { existing.remove(); } catch {}
      }

      // Create Overlay
      this.dom.overlay = el('div', `${PREFIX}overlay`);
      this.dom.overlay._layerInstance = this;

      // Create Popup
      this.dom.popup = el('div', `${PREFIX}popup`);
      this.dom.overlay.appendChild(this.dom.popup);

      // Flow mode: pre-mount all steps and switch by hide/show (DOM continuity, less jitter)
      if (meta && meta.flow) {
        this._renderFlowUI();
        return;
      }

      // Icon
      if (this.params.icon) {
        this.dom.icon = this._createIcon(this.params.icon);
        this.dom.popup.appendChild(this.dom.icon);
      }

      // Title
      if (this.params.title) {
        this.dom.title = el('h2', `${PREFIX}title`, this.params.title);
        this.dom.popup.appendChild(this.dom.title);
      }

      // Content (Text / HTML / Element)
      if (this.params.text || this.params.html || this.params.content || this.params.dom) {
        this.dom.content = el('div', `${PREFIX}content`);

        // DOM content (preferred: dom, backward: content)
        const domSpec = this._normalizeDomSpec(this.params);
        if (domSpec) {
          this._mountDomContent(domSpec);
        } else if (this.params.html) {
           this.dom.content.innerHTML = this.params.html;
        } else {
           this.dom.content.textContent = this.params.text;
        }
        
        this.dom.popup.appendChild(this.dom.content);
      }

      // Actions
      this.dom.actions = el('div', `${PREFIX}actions`);
      
      // Cancel Button
      if (this.params.showCancelButton) {
        this.dom.cancelBtn = el('button', `${PREFIX}button ${PREFIX}cancel`, this.params.cancelButtonText);
        this.dom.cancelBtn.style.backgroundColor = this.params.cancelButtonColor;
        this.dom.cancelBtn.onclick = () => this._handleCancel();
        this.dom.actions.appendChild(this.dom.cancelBtn);
      }

      // Confirm Button
      this.dom.confirmBtn = el('button', `${PREFIX}button ${PREFIX}confirm`, this.params.confirmButtonText);
      this.dom.confirmBtn.style.backgroundColor = this.params.confirmButtonColor;
      this.dom.confirmBtn.onclick = () => this._handleConfirm();
      this.dom.actions.appendChild(this.dom.confirmBtn);

      this.dom.popup.appendChild(this.dom.actions);

      // Event Listeners
      if (this.params.closeOnClickOutside) {
        this.dom.overlay.addEventListener('click', (e) => {
          if (e.target === this.dom.overlay) {
            this._close(null); // Dismiss
          }
        });
      }

      // Avoid first-open overlay "flash": wait for CSS before inserting into DOM,
      // then show on a clean frame so opacity transitions are smooth.
      const ready = this._cssReady && typeof this._cssReady.then === 'function' ? this._cssReady : Promise.resolve();
      ready.then(() => {
        try { this.dom.overlay.style.visibility = ''; } catch {}
        if (!this.dom.overlay.parentNode) {
          document.body.appendChild(this.dom.overlay);
        }
        // Double-rAF gives the browser a chance to apply styles before animating.
        requestAnimationFrame(() => {
          requestAnimationFrame(() => {
            this.dom.overlay.classList.add('show');
            this._didOpen();
          });
        });
      });
    }

    _renderFlowUI() {
      // Icon/title/content/actions are stable; steps are pre-mounted and toggled.
      const popup = this.dom.popup;
      if (!popup) return;

      // Clear popup
      while (popup.firstChild) popup.removeChild(popup.firstChild);

      // Icon (in flow: suppressed by default unless question or summary)
      this.dom.icon = null;
      if (this.params.icon) {
        this.dom.icon = this._createIcon(this.params.icon);
        popup.appendChild(this.dom.icon);
      }

      // Title (always present for flow)
      this.dom.title = el('h2', `${PREFIX}title`, this.params.title || '');
      popup.appendChild(this.dom.title);

      // Content container
      this.dom.content = el('div', `${PREFIX}content`);
      // Stack container: keep panes absolute so we can cross-fade without layout thrash
      this.dom.stepStack = el('div', `${PREFIX}step-stack`);
      this.dom.stepStack.style.position = 'relative';
      this.dom.stepStack.style.width = '100%';
      this.dom.stepPanes = [];
      this._flowMountedList = [];

      const steps = this._flowResolved || (this._flowSteps || []).map((_, i) => this._getFlowStepOptions(i));
      steps.forEach((opt, i) => {
        const pane = el('div', `${PREFIX}step-pane`);
        pane.style.width = '100%';
        pane.style.boxSizing = 'border-box';
        pane.style.display = (i === this._flowIndex) ? '' : 'none';

        // Fill pane: dom/html/text
        const domSpec = this._normalizeDomSpec(opt);
        if (domSpec) {
          this._mountDomContentInto(pane, domSpec, { collectFlow: true });
        } else if (opt.html) {
          pane.innerHTML = opt.html;
        } else if (opt.text) {
          pane.textContent = opt.text;
        }

        this.dom.stepStack.appendChild(pane);
        this.dom.stepPanes.push(pane);
      });

      this.dom.content.appendChild(this.dom.stepStack);
      popup.appendChild(this.dom.content);

      // Actions
      this.dom.actions = el('div', `${PREFIX}actions`);
      popup.appendChild(this.dom.actions);
      this._updateFlowActions();

      // Event Listeners
      if (this.params.closeOnClickOutside) {
        this.dom.overlay.addEventListener('click', (e) => {
          if (e.target === this.dom.overlay) {
            this._close(null, 'backdrop');
          }
        });
      }

      // Avoid first-open overlay "flash": wait for CSS before inserting into DOM,
      // then show on a clean frame so opacity transitions are smooth.
      const ready = this._cssReady && typeof this._cssReady.then === 'function' ? this._cssReady : Promise.resolve();
      ready.then(() => {
        try { this.dom.overlay.style.visibility = ''; } catch {}
        if (!this.dom.overlay.parentNode) {
          document.body.appendChild(this.dom.overlay);
        }
        requestAnimationFrame(() => {
          requestAnimationFrame(() => {
            this.dom.overlay.classList.add('show');
            this._didOpen();
          });
        });
      });
    }

    _updateFlowActions() {
      const actions = this.dom && this.dom.actions;
      if (!actions) return;
      while (actions.firstChild) actions.removeChild(actions.firstChild);

      this.dom.cancelBtn = null;
      if (this.params.showCancelButton) {
        this.dom.cancelBtn = el('button', `${PREFIX}button ${PREFIX}cancel`, this.params.cancelButtonText);
        this.dom.cancelBtn.style.backgroundColor = this.params.cancelButtonColor;
        this.dom.cancelBtn.onclick = () => this._handleCancel();
        actions.appendChild(this.dom.cancelBtn);
      }

      this.dom.confirmBtn = el('button', `${PREFIX}button ${PREFIX}confirm`, this.params.confirmButtonText);
      this.dom.confirmBtn.style.backgroundColor = this.params.confirmButtonColor;
      this.dom.confirmBtn.onclick = () => this._handleConfirm();
      actions.appendChild(this.dom.confirmBtn);
    }

    _createIcon(type) {
      const icon = el('div', `${PREFIX}icon ${type}`);
      const applyIconSize = (mode) => {
        if (!(this.params && this.params.iconSize)) return;
        try {
          const s = String(this.params.iconSize).trim();
          if (!s) return;
          // For SweetAlert2-style success icon, scale via font-size so all `em`-based parts remain proportional.
          if (mode === 'font') {
            const m = s.match(/^(-?\d*\.?\d+)\s*(px|em|rem)$/i);
            if (m) {
              const n = parseFloat(m[1]);
              const unit = m[2];
              if (Number.isFinite(n) && n > 0) {
                icon.style.fontSize = (n / 5) + unit; // icon is 5em wide/tall
                return;
              }
            }
          }
          // Fallback: directly size the box (works great for SVG icons)
          icon.style.width = s;
          icon.style.height = s;
        } catch {}
      };
      
      const appendRingParts = () => {
        // Use the same "success-like" ring parts for every built-in icon
        icon.appendChild(el('div', `${PREFIX}success-circular-line-left`));
        icon.appendChild(el('div', `${PREFIX}success-ring`));
        icon.appendChild(el('div', `${PREFIX}success-fix`));
        icon.appendChild(el('div', `${PREFIX}success-circular-line-right`));
      };
      
      const createInnerMarkSvg = () => {
        const svg = svgEl('svg');
        svg.setAttribute('viewBox', '0 0 80 80');
        svg.setAttribute('aria-hidden', 'true');
        svg.setAttribute('focusable', 'false');
        return svg;
      };
      
      const addMarkPath = (svg, d, extraClass) => {
        const p = svgEl('path');
        p.setAttribute('d', d);
        p.setAttribute('class', `${PREFIX}svg-mark ${PREFIX}svg-draw${extraClass ? ' ' + extraClass : ''}`);
        p.setAttribute('stroke', 'currentColor');
        svg.appendChild(p);
        return p;
      };
      
      const addDot = (svg, cx, cy) => {
        const dot = svgEl('circle');
        dot.setAttribute('class', `${PREFIX}svg-dot`);
        dot.setAttribute('cx', String(cx));
        dot.setAttribute('cy', String(cy));
        dot.setAttribute('r', '3.2');
        dot.setAttribute('fill', 'currentColor');
        svg.appendChild(dot);
        return dot;
      };
      
      const appendBuiltInInnerMark = (svg) => {
        if (type === 'error') {
          addMarkPath(svg, 'M28 28 L52 52', `${PREFIX}svg-error-left`);
          addMarkPath(svg, 'M52 28 L28 52', `${PREFIX}svg-error-right`);
        } else if (type === 'warning') {
          addMarkPath(svg, 'M40 20 L40 46', `${PREFIX}svg-warning-line`);
          addDot(svg, 40, 58);
        } else if (type === 'info') {
          addMarkPath(svg, 'M40 34 L40 56', `${PREFIX}svg-info-line`);
          addDot(svg, 40, 25);
        } else if (type === 'question') {
          addMarkPath(svg, 'M30 30 C30 23 35 19 42 19 C49 19 54 23 54 30 C54 36 50 39 46 41 C43 42 42 44 42 48 L42 52', `${PREFIX}svg-question`);
          addDot(svg, 42, 61);
        }
      };
      
      if (type === 'success') {
        // SweetAlert2-compatible DOM structure (circle + tick) for exact style parity
        //   <div class="...success-circular-line-left"></div>
        //   <div class="...success-mark"><span class="...success-line-tip"></span><span class="...success-line-long"></span></div>
        //   <div class="...success-ring"></div>
        //   <div class="...success-fix"></div>
        //   <div class="...success-circular-line-right"></div>
        icon.appendChild(el('div', `${PREFIX}success-circular-line-left`));
        const mark = el('div', `${PREFIX}success-mark`);
        mark.appendChild(el('span', `${PREFIX}success-line-tip`));
        mark.appendChild(el('span', `${PREFIX}success-line-long`));
        icon.appendChild(mark);
        icon.appendChild(el('div', `${PREFIX}success-ring`));
        icon.appendChild(el('div', `${PREFIX}success-fix`));
        icon.appendChild(el('div', `${PREFIX}success-circular-line-right`));

        applyIconSize('font');
        return icon;
      }

      if (type === 'error' || type === 'warning' || type === 'info' || type === 'question') {
        // Use the same "success-like" ring parts for every icon
        appendRingParts();

        applyIconSize('font');

        // SVG only draws the inner symbol (no SVG ring)
        const svg = createInnerMarkSvg();
        appendBuiltInInnerMark(svg);
        icon.appendChild(svg);
        return icon;
      }

      // Default to SVG icons for other/custom types
      applyIconSize('box');

      const svg = createInnerMarkSvg();

      const ring = svgEl('circle');
      ring.setAttribute('class', `${PREFIX}svg-ring ${PREFIX}svg-draw`);
      ring.setAttribute('cx', '40');
      ring.setAttribute('cy', '40');
      ring.setAttribute('r', '34');
      ring.setAttribute('stroke', 'currentColor');

      svg.appendChild(ring);
      // For custom types, we draw ring only by default (no inner mark).

      icon.appendChild(svg);
      
      return icon;
    }

    _adjustRingBackgroundColor() {
      try {
        const icon = this.dom && this.dom.icon;
        const popup = this.dom && this.dom.popup;
        if (!icon || !popup) return;
        const bg = getComputedStyle(popup).backgroundColor;
        const parts = icon.querySelectorAll(RING_BG_PARTS_SELECTOR);
        parts.forEach((el) => {
          try { el.style.backgroundColor = bg; } catch {}
        });
      } catch {}
    }

    _didOpen() {
      // Keyboard close (ESC)
      if (this.params.closeOnEsc) {
        this._onKeydown = (e) => {
          if (!e) return;
          if (e.key === 'Escape') this._close(null, 'esc');
        };
        document.addEventListener('keydown', this._onKeydown);
      }

      // Keep the "success-like" ring perfectly blended with popup bg
      this._adjustRingBackgroundColor();

      // Popup animation (optional)
      if (this.params.popupAnimation) {
        if (this.dom.popup) {
          // Use WAAPI directly to guarantee the slide+fade effect is visible,
          // independent from xjs.animate implementation details.
          try {
            const popup = this.dom.popup;
            try { popup.classList.add(`${PREFIX}popup-anim-slide`); } catch {}

            const rect = popup.getBoundingClientRect();
            // Default entrance: from above center by "more than half" of popup height.
            // Clamp to viewport so very tall popups don't start far off-screen.
            const vh = (typeof window !== 'undefined' && window && window.innerHeight) ? window.innerHeight : rect.height;
            const baseH = Math.min(rect.height, vh);
            const y0 = -Math.round(Math.max(18, baseH * 0.75));

            // Disable CSS transform transition so it won't fight with WAAPI.
            popup.style.transition = 'none';
            popup.style.willChange = 'transform, opacity';

            // If WAAPI is available, prefer it (most consistent).
            if (popup.animate) {
              const anim = popup.animate(
                [
                  { transform: `translateY(${y0}px) scale(0.92)`, opacity: 0 },
                  { transform: 'translateY(0px) scale(1)', opacity: 1 }
                ],
                {
                  duration: 520,
                  easing: 'cubic-bezier(0.2, 0.9, 0.2, 1)',
                  fill: 'forwards'
                }
              );
              anim.finished
                .catch(() => {})
                .finally(() => {
                  try { popup.style.willChange = ''; } catch {}
                });
            } else {
              // Fallback: try xjs.animate if WAAPI isn't available.
              const X = Layer._getXjs();
              if (X) {
                popup.style.opacity = '0';
                popup.style.transform = `translateY(${y0}px) scale(0.92)`;
                X(popup).animate({
                  y: [y0, 0],
                  scale: [0.92, 1],
                  opacity: [0, 1],
                  duration: 520,
                  easing: 'ease-out'
                });
              }
              setTimeout(() => {
                try { popup.style.willChange = ''; } catch {}
              }, 560);
            }
          } catch {}
        }
      }

      // Icon SVG draw animation
      if (this.params.iconAnimation) {
        this._animateIcon();
      }

      // User hook (SweetAlert-ish naming)
      try {
        if (typeof this.params.didOpen === 'function') this.params.didOpen(this.dom.popup);
      } catch {}
    }

    _animateIcon() {
      const icon = this.dom.icon;
      if (!icon) return;
      const type = (this.params && this.params.icon) || '';

      // Ring animation (same as success) for all built-in icons
      if (RING_TYPES.has(type)) this._adjustRingBackgroundColor();
      try { icon.classList.remove(`${PREFIX}icon-show`); } catch {}
      requestAnimationFrame(() => {
        try { icon.classList.add(`${PREFIX}icon-show`); } catch {}
      });

      // Success tick is CSS-driven; others still draw their SVG mark after the ring starts.
      if (type === 'success') return;

      const X = Layer._getXjs();
      if (!X) return;

      const svg = icon.querySelector('svg');
      if (!svg) return;

      const marks = Array.from(svg.querySelectorAll(`.${PREFIX}svg-mark`));
      const dot = svg.querySelector(`.${PREFIX}svg-dot`);

      // If this is a built-in icon, keep the SweetAlert-like order:
      // ring sweep first (~0.51s), then draw the inner mark.
      const baseDelay = RING_TYPES.has(type) ? 520 : 0;

      if (type === 'error') {
        // Draw order: left-top -> right-bottom, then right-top -> left-bottom
        // NOTE: A tiny delay (like 70ms) looks simultaneous; make it strictly sequential.
        const a = svg.querySelector(`.${PREFIX}svg-error-left`) || marks[0];  // M28 28 L52 52
        const b = svg.querySelector(`.${PREFIX}svg-error-right`) || marks[1]; // M52 28 L28 52
        const dur = 320;
        const gap = 60;
        try { if (a) X(a).draw({ duration: dur, easing: 'ease-out', delay: baseDelay }); } catch {}
        try { if (b) X(b).draw({ duration: dur, easing: 'ease-out', delay: baseDelay + dur + gap }); } catch {}
      } else {
        // warning / info / question (single stroke) or custom SVG symbols
        marks.forEach((m, i) => {
          try { X(m).draw({ duration: 420, easing: 'ease-out', delay: baseDelay + i * 60 }); } catch {}
        });
      }

      if (dot) {
        try {
          dot.style.opacity = '0';
          // Keep dot pop after the ring begins
          const d = baseDelay + 140;
          if (type === 'info') {
            X(dot).animate({ opacity: [0, 1], y: [-8, 0], scale: [0.2, 1], duration: 420, delay: d, easing: { stiffness: 300, damping: 14 } });
          } else {
            X(dot).animate({ opacity: [0, 1], scale: [0.2, 1], duration: 320, delay: d, easing: { stiffness: 320, damping: 18 } });
          }
        } catch {}
      }
    }

    _forceDestroy(reason = 'replace') {
      // Restore mounted DOM (if any) and cleanup listeners; also resolve the promise so it doesn't hang.
      try { this._unmountDomContent(); } catch {}
      if (this._onKeydown) {
        try { document.removeEventListener('keydown', this._onKeydown); } catch {}
        this._onKeydown = null;
      }
      try {
        if (this.resolve) {
          this.resolve({ isConfirmed: false, isDenied: false, isDismissed: true, dismiss: reason });
        }
      } catch {}
    }

    _close(isConfirmed, reason) {
      if (this._isClosing) return;
      this._isClosing = true;

      // Restore mounted DOM (moved into popup) before removing overlay
      try {
        if (this._flowSteps && this._flowSteps.length) this._unmountFlowMounted();
        else this._unmountDomContent();
      } catch {}

      this.dom.overlay.classList.remove('show');
      setTimeout(() => {
        if (this.dom.overlay && this.dom.overlay.parentNode) {
          this.dom.overlay.parentNode.removeChild(this.dom.overlay);
        }
      }, 300);

      if (this._onKeydown) {
        try { document.removeEventListener('keydown', this._onKeydown); } catch {}
        this._onKeydown = null;
      }

      try {
        if (typeof this.params.willClose === 'function') this.params.willClose(this.dom.popup);
      } catch {}
      try {
        if (typeof this.params.didClose === 'function') this.params.didClose();
      } catch {}

      const value = (this._flowSteps && this._flowSteps.length) ? (this._flowValues || []) : undefined;
      if (isConfirmed === true) {
        this.resolve({ isConfirmed: true, isDenied: false, isDismissed: false, value });
      } else if (isConfirmed === false) {
        this.resolve({ isConfirmed: false, isDenied: false, isDismissed: true, dismiss: reason || 'cancel', value });
      } else {
        this.resolve({ isConfirmed: false, isDenied: false, isDismissed: true, dismiss: reason || 'backdrop', value });
      }
    }

    _normalizeDomSpec(params) {
      // Preferred: params.dom (selector/Element/template)
      // Backward: params.content (selector/Element) OR advanced object { dom, mode, clone }
      const p = params || {};
      let dom = p.dom;
      let mode = p.domMode || 'move';

      if (dom == null && p.content != null) {
        if (typeof p.content === 'object' && !(p.content instanceof Element)) {
          if (p.content && (p.content.dom != null || p.content.selector != null)) {
            dom = (p.content.dom != null) ? p.content.dom : p.content.selector;
            if (p.content.mode) mode = p.content.mode;
            if (p.content.clone === true) mode = 'clone';
          }
        } else {
          dom = p.content;
        }
      }

      if (dom == null) return null;
      return { dom, mode };
    }

    _mountDomContentInto(target, domSpec, opts = null) {
      // Like _mountDomContent, but mounts into the provided container.
      const collectFlow = !!(opts && opts.collectFlow);
      const originalContent = this.dom.content;
      // Temporarily redirect this.dom.content for reuse of internal logic.
      try { this.dom.content = target; } catch {}
      try {
        const before = this._mounted;
        this._mountDomContent(domSpec);
        const rec = this._mounted;
        // If we mounted in move-mode, _mounted holds record; detach it from single-mode tracking.
        if (collectFlow && rec && rec.kind === 'move') {
          this._flowMountedList.push(rec);
          this._mounted = before; // restore previous single record (usually null)
        }
      } finally {
        try { this.dom.content = originalContent; } catch {}
      }
    }

    _unmountFlowMounted() {
      // Restore all moved DOM nodes for flow steps
      const list = Array.isArray(this._flowMountedList) ? this._flowMountedList : [];
      this._flowMountedList = [];
      list.forEach((m) => {
        try {
          if (!m || m.kind !== 'move') return;
          // Reuse single unmount logic by swapping _mounted
          const prev = this._mounted;
          this._mounted = m;
          this._unmountDomContent();
          this._mounted = prev;
        } catch {}
      });
    }

    _mountDomContent(domSpec) {
      try {
        if (!this.dom.content) return;
        this._unmountDomContent(); // ensure only one mount at a time

        const forceVisible = (el) => {
          if (!el) return { prevHidden: false, prevInlineDisplay: '' };
          const prevHidden = !!el.hidden;
          const prevInlineDisplay = (el.style && typeof el.style.display === 'string') ? el.style.display : '';
          try { el.hidden = false; } catch {}
          try {
            const cs = (typeof getComputedStyle === 'function') ? getComputedStyle(el) : null;
            const display = cs ? String(cs.display || '') : '';
            // If element is hidden via CSS (e.g. .hidden-dom{display:none}),
            // add an inline override so it becomes visible inside the popup.
            if (display === 'none') el.style.display = 'block';
            else if (el.style && el.style.display === 'none') el.style.display = 'block';
          } catch {}
          return { prevHidden, prevInlineDisplay };
        };

        let node = domSpec.dom;
        if (typeof node === 'string') node = document.querySelector(node);
        if (!node) return;

        // <template> support: always clone template content
        if (typeof HTMLTemplateElement !== 'undefined' && node instanceof HTMLTemplateElement) {
          const frag = node.content.cloneNode(true);
          this.dom.content.appendChild(frag);
          this._mounted = { kind: 'template' };
          return;
        }

        if (!(node instanceof Element)) return;

        if (domSpec.mode === 'clone') {
          const clone = node.cloneNode(true);
          // If original is hidden (via attr or CSS), the clone may inherit; force show it in popup.
          try { clone.hidden = false; } catch {}
          try {
            const cs = (typeof getComputedStyle === 'function') ? getComputedStyle(node) : null;
            const display = cs ? String(cs.display || '') : '';
            if (display === 'none') clone.style.display = 'block';
          } catch {}
          this.dom.content.appendChild(clone);
          this._mounted = { kind: 'clone' };
          return;
        }

        // Default: move into popup but restore on close
        const placeholder = document.createComment('layer-dom-placeholder');
        const parent = node.parentNode;
        const nextSibling = node.nextSibling;
        if (!parent) {
          // Detached node: moving would lose it when overlay is removed; clone instead.
          const clone = node.cloneNode(true);
          try { clone.hidden = false; } catch {}
          try { if (clone.style && clone.style.display === 'none') clone.style.display = ''; } catch {}
          this.dom.content.appendChild(clone);
          this._mounted = { kind: 'clone' };
          return;
        }

        try { parent.insertBefore(placeholder, nextSibling); } catch {}

        const { prevHidden, prevInlineDisplay } = forceVisible(node);

        this.dom.content.appendChild(node);
        this._mounted = { kind: 'move', originalEl: node, placeholder, parent, nextSibling, prevHidden, prevInlineDisplay };
      } catch {
        // ignore
      }
    }

    _unmountDomContent() {
      const m = this._mounted;
      if (!m) return;
      this._mounted = null;

      if (m.kind !== 'move') return;
      const node = m.originalEl;
      if (!node) return;

      // Restore hidden/display
      try { node.hidden = !!m.prevHidden; } catch {}
      try {
        if (node.style && typeof m.prevInlineDisplay === 'string') node.style.display = m.prevInlineDisplay;
      } catch {}

      // Move back to original position
      try {
        const ph = m.placeholder;
        if (ph && ph.parentNode) {
          ph.parentNode.insertBefore(node, ph);
          ph.parentNode.removeChild(ph);
          return;
        }
      } catch {}

      // Fallback: append to original parent
      try {
        if (m.parent) m.parent.appendChild(node);
      } catch {}
    }

    _setButtonsDisabled(disabled) {
      try {
        if (this.dom && this.dom.confirmBtn) this.dom.confirmBtn.disabled = !!disabled;
        if (this.dom && this.dom.cancelBtn) this.dom.cancelBtn.disabled = !!disabled;
      } catch {}
    }

    async _handleConfirm() {
      // Flow next / finalize
      if (this._flowSteps && this._flowSteps.length) {
        return this._flowNext();
      }

      // Single popup: support async preConfirm
      const pre = this.params && this.params.preConfirm;
      if (typeof pre === 'function') {
        try {
          this._setButtonsDisabled(true);
          const r = pre(this.dom && this.dom.popup);
          const v = (r && typeof r.then === 'function') ? await r : r;
          if (v === false) {
            this._setButtonsDisabled(false);
            return;
          }
          // store value in non-flow mode as single value
          this._flowValues = [v];
        } catch (e) {
          console.error(e);
          this._setButtonsDisabled(false);
          return;
        }
      }

      this._close(true, 'confirm');
    }

    _handleCancel() {
      if (this._flowSteps && this._flowSteps.length) {
        // default: if not first step, cancel acts as "back"
        if (this._flowIndex > 0) {
          this._flowPrev();
          return;
        }
      }
      this._close(false, 'cancel');
    }

    _getFlowStepOptions(index) {
      const step = (this._flowSteps && this._flowSteps[index]) ? this._flowSteps[index] : {};
      const base = this._flowBase || {};
      const merged = { ...base, ...step };

      // Default button texts for flow
      const isLast = index >= (this._flowSteps.length - 1);
      if (!('confirmButtonText' in step)) merged.confirmButtonText = isLast ? (base.confirmButtonText || 'OK') : 'Next';

      // Show cancel as Back after first step (unless step explicitly overrides)
      if (index > 0) {
        if (!('showCancelButton' in step)) merged.showCancelButton = true;
        if (!('cancelButtonText' in step)) merged.cancelButtonText = 'Back';
      } else {
        // First step default keeps base settings
        if (!('cancelButtonText' in step) && merged.showCancelButton) merged.cancelButtonText = merged.cancelButtonText || 'Cancel';
      }

      // Icon/animation policy for flow:
      // - During steps: no icon/animations by default (avoids distraction + layout jitter)
      // - Allow icon only if step explicitly uses `icon:'question'`, or step is marked as summary.
      const isSummary = !!(step && (step.summary === true || step.isSummary === true));
      const explicitIcon = ('icon' in step) ? step.icon : undefined;
      const baseIcon = ('icon' in base) ? base.icon : undefined;
      const chosenIcon = (explicitIcon !== undefined) ? explicitIcon : baseIcon;

      if (!isSummary && !isLast) {
        merged.icon = (chosenIcon === 'question') ? 'question' : null;
        merged.iconAnimation = false;
      } else if (!isSummary && isLast) {
        // last step: still suppress unless summary or question
        merged.icon = (chosenIcon === 'question') ? 'question' : null;
        merged.iconAnimation = false;
      } else {
        // summary step: allow icon; animation follows explicit config (default true only if provided elsewhere)
        if (!('icon' in step) && chosenIcon === undefined) merged.icon = null;
      }

      return merged;
    }

    async _flowNext() {
      const idx = this._flowIndex;
      const total = this._flowSteps.length;
      const isLast = idx >= (total - 1);

      // preConfirm hook for current step
      const pre = this.params && this.params.preConfirm;
      if (typeof pre === 'function') {
        try {
          this._setButtonsDisabled(true);
          const r = pre(this.dom && this.dom.popup, idx);
          const v = (r && typeof r.then === 'function') ? await r : r;
          if (v === false) {
            this._setButtonsDisabled(false);
            return;
          }
          this._flowValues[idx] = v;
        } catch (e) {
          console.error(e);
          this._setButtonsDisabled(false);
          return;
        }
      }

      if (isLast) {
        this._close(true, 'confirm');
        return;
      }

      this._setButtonsDisabled(false);
      await this._flowGo(idx + 1, 'next');
    }

    async _flowPrev() {
      const idx = this._flowIndex;
      if (idx <= 0) return;
      await this._flowGo(idx - 1, 'prev');
    }

    async _flowGo(index, direction) {
      const next = (this._flowResolved && this._flowResolved[index]) ? this._flowResolved[index] : this._getFlowStepOptions(index);
      await this._transitionToFlow(index, next, direction);
    }

    async _transitionToFlow(nextIndex, nextOptions, direction) {
      const popup = this.dom && this.dom.popup;
      const content = this.dom && this.dom.content;
      const panes = this.dom && this.dom.stepPanes;
      if (!popup || !content || !panes || !panes.length) {
        this._flowIndex = nextIndex;
        this.params = nextOptions;
        this._render({ flow: true });
        return;
      }

      const fromIndex = this._flowIndex;
      const fromPane = panes[fromIndex];
      const toPane = panes[nextIndex];
      if (!fromPane || !toPane) {
        this._flowIndex = nextIndex;
        this.params = nextOptions;
        this._render({ flow: true });
        return;
      }

      // Measure current content height
      const oldH = content.getBoundingClientRect().height;

      // Prepare target pane for measurement without affecting layout
      const prevDisplay = toPane.style.display;
      const prevPos = toPane.style.position;
      const prevVis = toPane.style.visibility;
      const prevPointer = toPane.style.pointerEvents;
      toPane.style.display = '';
      toPane.style.position = 'absolute';
      toPane.style.visibility = 'hidden';
      toPane.style.pointerEvents = 'none';
      toPane.style.left = '0';
      toPane.style.right = '0';

      const newH = toPane.getBoundingClientRect().height;

      // Restore pane styles (keep hidden until animation starts)
      toPane.style.position = prevPos;
      toPane.style.visibility = prevVis;
      toPane.style.pointerEvents = prevPointer;
      toPane.style.display = prevDisplay; // usually 'none'

      // Apply new options (title/buttons/icon policy) before showing the pane
      this._flowIndex = nextIndex;
      this.params = nextOptions;

      // Update icon/title/buttons without recreating DOM
      try {
        if (this.dom.title) this.dom.title.textContent = this.params.title || '';
      } catch {}

      // Icon updates (only if needed)
      try {
        const wantsIcon = !!this.params.icon;
        if (!wantsIcon && this.dom.icon) {
          this.dom.icon.remove();
          this.dom.icon = null;
        } else if (wantsIcon) {
          const curType = this.dom.icon ? (Array.from(this.dom.icon.classList).find(c => c !== `${PREFIX}icon`) || '') : '';
          if (!this.dom.icon || !this.dom.icon.classList.contains(String(this.params.icon))) {
            if (this.dom.icon) this.dom.icon.remove();
            this.dom.icon = this._createIcon(this.params.icon);
            // icon should be on top (before title)
            popup.insertBefore(this.dom.icon, this.dom.title || popup.firstChild);
          }
        }
      } catch {}

      this._updateFlowActions();

      // Switch panes with smooth opacity/translate; animate content height to reduce jitter
      const dy = (direction === 'prev') ? -8 : 8;

      // Show both panes during animation (stacked)
      toPane.style.display = '';
      toPane.style.position = 'relative';
      toPane.style.opacity = '0';
      toPane.style.transform = `translateY(${dy}px)`;
      toPane.style.willChange = 'opacity, transform';
      fromPane.style.willChange = 'opacity, transform';

      // Lock content height during transition
      content.style.height = oldH + 'px';
      content.style.overflow = 'hidden';

      // Animate height
      let heightAnim = null;
      try {
        heightAnim = content.animate(
          [{ height: oldH + 'px' }, { height: newH + 'px' }],
          { duration: 220, easing: 'cubic-bezier(0.2, 0.9, 0.2, 1)', fill: 'forwards' }
        );
      } catch {}

      // Animate panes
      try {
        fromPane.animate(
          [{ opacity: 1, transform: 'translateY(0px)' }, { opacity: 0, transform: `translateY(${-dy}px)` }],
          { duration: 160, easing: 'ease-out', fill: 'forwards' }
        );
      } catch {}

      let paneIn = null;
      try {
        paneIn = toPane.animate(
          [{ opacity: 0, transform: `translateY(${dy}px)` }, { opacity: 1, transform: 'translateY(0px)' }],
          { duration: 220, easing: 'cubic-bezier(0.2, 0.9, 0.2, 1)', fill: 'forwards' }
        );
      } catch {}

      try {
        await Promise.all([
          heightAnim && heightAnim.finished ? heightAnim.finished.catch(() => {}) : Promise.resolve(),
          paneIn && paneIn.finished ? paneIn.finished.catch(() => {}) : Promise.resolve()
        ]);
      } catch {}

      // Cleanup styles and hide old pane
      fromPane.style.display = 'none';
      fromPane.style.willChange = '';
      toPane.style.willChange = '';
      toPane.style.opacity = '';
      toPane.style.transform = '';
      content.style.height = '';
      content.style.overflow = '';

      // Re-adjust ring background if icon exists (rare in flow)
      try { this._adjustRingBackgroundColor(); } catch {}
    }

    _rerenderInside() {
      // Update popup content without recreating overlay (used in flow transitions)
      const popup = this.dom && this.dom.popup;
      if (!popup) return;

      // Clear popup (but keep reference)
      while (popup.firstChild) popup.removeChild(popup.firstChild);

      // Icon
      this.dom.icon = null;
      if (this.params.icon) {
        this.dom.icon = this._createIcon(this.params.icon);
        popup.appendChild(this.dom.icon);
      }

      // Title
      this.dom.title = null;
      if (this.params.title) {
        this.dom.title = el('h2', `${PREFIX}title`, this.params.title);
        popup.appendChild(this.dom.title);
      }

      // Content
      this.dom.content = null;
      if (this.params.text || this.params.html || this.params.content || this.params.dom) {
        this.dom.content = el('div', `${PREFIX}content`);
        const domSpec = this._normalizeDomSpec(this.params);
        if (domSpec) this._mountDomContent(domSpec);
        else if (this.params.html) this.dom.content.innerHTML = this.params.html;
        else this.dom.content.textContent = this.params.text;
        popup.appendChild(this.dom.content);
      }

      // Actions / buttons
      this.dom.actions = el('div', `${PREFIX}actions`);
      this.dom.cancelBtn = null;
      if (this.params.showCancelButton) {
        this.dom.cancelBtn = el('button', `${PREFIX}button ${PREFIX}cancel`, this.params.cancelButtonText);
        this.dom.cancelBtn.style.backgroundColor = this.params.cancelButtonColor;
        this.dom.cancelBtn.onclick = () => this._handleCancel();
        this.dom.actions.appendChild(this.dom.cancelBtn);
      }

      this.dom.confirmBtn = el('button', `${PREFIX}button ${PREFIX}confirm`, this.params.confirmButtonText);
      this.dom.confirmBtn.style.backgroundColor = this.params.confirmButtonColor;
      this.dom.confirmBtn.onclick = () => this._handleConfirm();
      this.dom.actions.appendChild(this.dom.confirmBtn);

      popup.appendChild(this.dom.actions);

      // Re-run open hooks for each step
      try {
        if (typeof this.params.didOpen === 'function') this.params.didOpen(this.dom.popup);
      } catch {}
    }
  }

  return Layer;

})));