/**
 * 画个标 · 核心：状态管理（Store）
 * 职责：维护设计数据、元素 CRUD、撤销/重做、事件订阅、版本快照
 */
const HGB_Store = (function () {
  'use strict';

  const CANVAS_W = 600;
  const CANVAS_H = 600;
  const MAX_HISTORY = 60;
  const LS_KEY = 'hgb_design';
  const LS_VERSION_KEY = 'hgb_versions';

  /* ---------- 默认项目 ---------- */
  function defaultProject() {
    return {
      name: '我的品牌',
      bg: '#FFFFFF',
      elements: [
        {
          id: uid(),
          type: 'icon',
          name: '学士帽',
          iconId: 'graduation-cap',
          svg: iconSvg('graduation-cap'),
          x: 210, y: 150, w: 180, h: 180,
          rotation: 0,
          fill: 'none',
          stroke: '#1B4F72',
          strokeWidth: 2,
          opacity: 1,
          visible: true, locked: false
        },
        {
          id: uid(),
          type: 'text',
          name: '品牌中文名',
          text: '远渡教育',
          x: 130, y: 360, w: 340, h: 64,
          rotation: 0,
          fontSize: 48,
          fontWeight: 700,
          fontFamily: 'SimHei',
          letterSpacing: 8,
          fill: '#1B4F72',
          stroke: 'none',
          strokeWidth: 0,
          opacity: 1,
          visible: true, locked: false
        },
        {
          id: uid(),
          type: 'text',
          name: '品牌英文名',
          text: 'FAR CROSS EDUCATION',
          x: 130, y: 430, w: 340, h: 32,
          rotation: 0,
          fontSize: 18,
          fontWeight: 400,
          fontFamily: 'Georgia',
          letterSpacing: 4,
          fill: '#2980B9',
          stroke: 'none',
          strokeWidth: 0,
          opacity: 1,
          visible: true, locked: false
        }
      ],
      selectedId: null,
      selectedIds: [],
      currentStyle: null
    };
  }

  /* ---------- 工具 ---------- */
  function uid() {
    return 'el_' + Date.now().toString(36) + Math.random().toString(36).slice(2, 7);
  }

  function iconSvg(iconId) {
    // 行业模块图标 + 基础图形
    for (const ind of HGB_Industries) {
      const ic = (ind.icons || []).find(i => i.id === iconId);
      if (ic) return ic.svg;
    }
    const ic = HGB_Icons.shapes.find(i => i.id === iconId);
    return ic ? ic.svg : '';
  }

  /* ---------- 状态 ---------- */
  let state = defaultProject();
  let history = [];
  let historyIdx = -1;
  let listeners = {};

  /* ---------- 历史记录 ---------- */
  function snapshot() {
    return JSON.parse(JSON.stringify(state));
  }

  function pushHistory() {
    // 移除 redo 分支
    history = history.slice(0, historyIdx + 1);
    history.push(snapshot());
    if (history.length > MAX_HISTORY) history.shift();
    historyIdx = history.length - 1;
    emit('history');
  }

  function undo() {
    if (historyIdx <= 0) return false;
    historyIdx--;
    state = JSON.parse(JSON.stringify(history[historyIdx]));
    emit('change');
    return true;
  }

  function redo() {
    if (historyIdx >= history.length - 1) return false;
    historyIdx++;
    state = JSON.parse(JSON.stringify(history[historyIdx]));
    emit('change');
    return true;
  }

  function canUndo() { return historyIdx > 0; }
  function canRedo() { return historyIdx < history.length - 1; }

  /* ---------- 元素操作 ---------- */
  function addElement(el) {
    state.elements.push(el);
    state.selectedId = el.id;
    pushHistory();
    emit('change');
    return el;
  }

  function updateElement(id, patch, record = true) {
    const el = state.elements.find(e => e.id === id);
    if (!el) return;
    Object.assign(el, patch);
    if (record) pushHistory();
    emit('change');
  }

  function removeElement(id) {
    state.elements = state.elements.filter(e => e.id !== id);
    if (state.selectedId === id) state.selectedId = null;
    pushHistory();
    emit('change');
  }

  /** 载入智能方案（替换全部元素与背景） */
  function loadPlan(plan) {
    state.elements = (plan.elements || []).map(e => ({ ...e }));
    state.bg = plan.bg || '#FFFFFF';
    state.selectedId = null;
    pushHistory();
    emit('change');
  }

  function duplicateElement(id) {
    const src = state.elements.find(e => e.id === id);
    if (!src) return null;
    const copy = JSON.parse(JSON.stringify(src));
    copy.id = uid();
    copy.name = src.name + ' 副本';
    copy.x += 24; copy.y += 24;
    // 副本放置到顶层
    state.elements.push(copy);
    state.selectedId = copy.id;
    pushHistory();
    emit('change');
    return copy;
  }

  function select(id, additive) {
    if (additive && id != null) {
      // Shift 多选：切换选中
      if (state.selectedIds.includes(id)) {
        state.selectedIds = state.selectedIds.filter(x => x !== id);
        state.selectedId = state.selectedIds.length ? state.selectedIds[state.selectedIds.length - 1] : null;
      } else {
        state.selectedIds.push(id);
        state.selectedId = id;
      }
    } else {
      state.selectedIds = id != null ? [id] : [];
      state.selectedId = id;
    }
    emit('select');
    emit('change');
  }

  /** 当前所有选中元素 */
  function selectedElements() {
    return state.selectedIds.map(id => state.elements.find(e => e.id === id)).filter(Boolean);
  }

  /** 移动全部选中元素 */
  function moveSelection(dx, dy) {
    for (const el of selectedElements()) {
      el.x = Math.round(el.x + dx);
      el.y = Math.round(el.y + dy);
    }
    emit('change');
  }

  /** 对齐全部选中元素 */
  function alignSelection(mode) {
    const els = selectedElements();
    if (els.length < 2) return;
    const xs = els.map(e => e.x), xes = els.map(e => e.x + e.w);
    const ys = els.map(e => e.y), yes = els.map(e => e.y + e.h);
    const minX = Math.min(...xs), maxX = Math.max(...xes);
    const minY = Math.min(...ys), maxY = Math.max(...yes);
    const boxCx = (minX + maxX) / 2, boxCy = (minY + maxY) / 2;
    for (const el of els) {
      if (mode === 'left') el.x = minX;
      else if (mode === 'center') el.x = Math.round(boxCx - el.w / 2);
      else if (mode === 'right') el.x = Math.round(maxX - el.w);
      else if (mode === 'top') el.y = minY;
      else if (mode === 'middle') el.y = Math.round(boxCy - el.h / 2);
      else if (mode === 'bottom') el.y = Math.round(maxY - el.h);
    }
    pushHistory(); emit('change');
  }

  /** 复制全部选中元素 */
  function duplicateSelection() {
    const srcs = selectedElements();
    if (!srcs.length) return 0;
    for (const src of srcs) {
      const copy = JSON.parse(JSON.stringify(src));
      copy.id = uid();
      copy.name = src.name + ' 副本';
      copy.x += 24; copy.y += 24;
      state.elements.push(copy);
      state.selectedIds.push(copy.id);
      state.selectedId = copy.id;
    }
    pushHistory(); emit('change');
    return srcs.length;
  }

  /** 粘贴剪贴板元素（生成新副本并选中） */
  function pasteElements(list) {
    if (!list || !list.length) return [];
    const newEls = list.map(src => {
      const copy = JSON.parse(JSON.stringify(src));
      copy.id = uid();
      copy.name = src.name + ' 副本';
      copy.x += 24; copy.y += 24;
      state.elements.push(copy);
      state.selectedIds.push(copy.id);
      state.selectedId = copy.id;
      return copy;
    });
    pushHistory(); emit('change');
    return newEls;
  }

  /** 删除全部选中元素 */
  function removeSelection() {
    if (!state.selectedIds.length) return 0;
    const ids = state.selectedIds.slice();
    state.elements = state.elements.filter(e => !ids.includes(e.id));
    state.selectedIds = [];
    state.selectedId = null;
    pushHistory(); emit('change');
    return ids.length;
  }

  /* ---------- 图层排序 ---------- */
  // elements 数组顺序即显示顺序（后画在上层）
  function layerUp(id) {
    const i = state.elements.findIndex(e => e.id === id);
    if (i < 0 || i >= state.elements.length - 1) return;
    [state.elements[i], state.elements[i + 1]] = [state.elements[i + 1], state.elements[i]];
    pushHistory(); emit('change');
  }
  function layerDown(id) {
    const i = state.elements.findIndex(e => e.id === id);
    if (i <= 0) return;
    [state.elements[i], state.elements[i - 1]] = [state.elements[i - 1], state.elements[i]];
    pushHistory(); emit('change');
  }
  function layerFront(id) {
    const el = state.elements.find(e => e.id === id);
    if (!el) return;
    state.elements = state.elements.filter(e => e.id !== id);
    state.elements.push(el);
    pushHistory(); emit('change');
  }
  function layerBack(id) {
    const el = state.elements.find(e => e.id === id);
    if (!el) return;
    state.elements = state.elements.filter(e => e.id !== id);
    state.elements.unshift(el);
    pushHistory(); emit('change');
  }

  /** 拖拽图层：将 fromIndex 元素移动到 toIndex 位置（占据目标位置，其余元素顺移） */
  function moveLayer(fromIndex, toIndex) {
    const len = state.elements.length;
    if (fromIndex < 0 || fromIndex >= len || toIndex < 0 || toIndex >= len) return;
    if (fromIndex === toIndex) return;
    const [el] = state.elements.splice(fromIndex, 1);
    state.elements.splice(toIndex, 0, el);
    pushHistory(); emit('change');
  }

  /* ---------- 风格应用 ---------- */
  function applyStyle(style) {
    state.currentStyle = style.id;
    state.bg = style.bg;
    for (const el of state.elements) {
      if (el.type === 'icon') {
        el.stroke = style.iconStroke;
        el.strokeWidth = style.strokeWidth;
      } else if (el.type === 'text') {
        el.fill = style.colors.primary;
        if (el.fontFamily === 'SimHei' || el.fontFamily === 'Microsoft YaHei' || el.fontFamily === '黑体') {
          el.fontFamily = style.fontCn;
        }
      }
    }
    pushHistory();
    emit('change');
    emit('style');
  }

  /* ---------- 配色应用 ---------- */
  function applyPalette(pal) {
    let idx = 0;
    for (const el of state.elements) {
      if (el.type === 'icon') {
        el.stroke = pal.colors[Math.min(idx, 1)];
        idx++;
      } else if (el.type === 'text') {
        el.fill = pal.colors[0];
      }
    }
    pushHistory();
    emit('change');
    emit('style');
  }

  /* ---------- 字体应用 ---------- */
  function applyFont(family, web) {
    const el = selected();
    if (!el || el.type !== 'text') return;
    if (web) HGB_Fonts.loadWebFont(family);
    updateElement(el.id, { fontFamily: family });
  }

  /* ---------- 版本快照 ---------- */
  function saveVersion() {
    const versions = loadVersions();
    const v = {
      id: uid(),
      time: Date.now(),
      name: state.name || '未命名设计',
      snapshot: snapshot()
    };
    versions.unshift(v);
    saveVersions(versions);
    emit('versions');
    return v;
  }

  function loadVersions() {
    try {
      return JSON.parse(localStorage.getItem(LS_VERSION_KEY)) || [];
    } catch (e) { return []; }
  }

  function saveVersions(list) {
    localStorage.setItem(LS_VERSION_KEY, JSON.stringify(list.slice(0, 50)));
  }

  function restoreVersion(id) {
    const v = loadVersions().find(x => x.id === id);
    if (!v) return false;
    state = JSON.parse(JSON.stringify(v.snapshot));
    pushHistory();
    emit('change');
    return true;
  }

  function deleteVersion(id) {
    saveVersions(loadVersions().filter(x => x.id !== id));
    emit('versions');
  }

  function clearVersions() {
    saveVersions([]);
    emit('versions');
  }

  /* ---------- 事件订阅 ---------- */
  function on(evt, fn) {
    (listeners[evt] = listeners[evt] || []).push(fn);
  }

  function emit(evt) {
    (listeners[evt] || []).forEach(fn => fn());
  }

  /* ---------- 选择器 ---------- */
  function get() { return state; }
  function selected() {
    return state.elements.find(e => e.id === state.selectedId) || null;
  }
  function selectedIndex() {
    return state.elements.findIndex(e => e.id === state.selectedId);
  }

  /* ---------- 本地持久化 ---------- */
  function persistToLocal() {
    try {
      const data = { ...snapshot(), savedAt: Date.now() };
      localStorage.setItem(LS_KEY, JSON.stringify(data));
      return true;
    } catch (e) { return false; }
  }

  function loadFromLocal() {
    try {
      const raw = localStorage.getItem(LS_KEY);
      if (!raw) return false;
      const data = JSON.parse(raw);
      if (data && Array.isArray(data.elements)) {
        state = data;
        // 迁移遗留演示默认名：历史版本默认项目名「我的留学教育品牌」会污染各行业生成时的品牌回退
        if (state.name === '我的留学教育品牌') state.name = '我的品牌';
        history = [snapshot()];
        historyIdx = 0;
        return true;
      }
    } catch (e) { /* ignore */ }
    return false;
  }

  /* ---------- 初始化 ---------- */
  function init(restoreLocal = true) {
    if (restoreLocal && loadFromLocal()) return;
    state = defaultProject();
    history = [snapshot()];
    historyIdx = 0;
  }

  return {
    CANVAS_W, CANVAS_H,
    get, selected, selectedIndex,
    selectedElements, moveSelection, alignSelection,
    duplicateSelection, removeSelection, pasteElements,
    addElement, updateElement, removeElement, duplicateElement, loadPlan, select,
    layerUp, layerDown, layerFront, layerBack, moveLayer,
    applyStyle, applyPalette, applyFont,
    undo, redo, canUndo, canRedo, pushHistory,
    saveVersion, loadVersions, restoreVersion, deleteVersion, clearVersions,
    persistToLocal, loadFromLocal, init,
    on, emit, uid, iconSvg
  };
})();