import { layui } from '../core/layui.js';
import { lay } from '../core/lay.js';
import { i18n } from '../core/i18n.js';
import $ from 'jquery';
import { laytpl } from '../core/laytpl.js';
import { util } from './util.js';

/**
 * dropdown
 * 下拉菜单组件
 */

var device = layui.device();
var clickOrMousedown = device.mobile ? 'touchstart' : 'mousedown';

// 模块名
var MOD_NAME = 'dropdown';
var MOD_INDEX = 'layui_' + MOD_NAME + '_index'; // 模块索引名
var MOD_INDEX_OPENED = MOD_INDEX + '_opened';
var MOD_ID = 'lay-' + MOD_NAME + '-id';
var resizeObserver = lay.createSharedResizeObserver(MOD_NAME);

// 外部接口
var dropdown = {
  config: {
    customName: {
      // 自定义 data 字段名
      id: 'id',
      title: 'title',
      children: 'child'
    }
  },
  // 设置全局项
  set: function (options) {
    var that = this;
    that.config = $.extend({}, that.config, options);
    return that;
  },
  // 事件
  on: function (events, callback) {
    return layui.onevent.call(this, MOD_NAME, events, callback);
  }
};

// 操作当前实例
var thisModule = function () {
  var that = this;
  var options = that.config;
  var id = options.id;
  return {
    config: options,
    // 重置实例
    reload: function (options) {
      that.reload.call(that, options);
    },
    reloadData: function (options) {
      dropdown.reloadData(id, options);
    },
    close: function () {
      that.remove();
    },
    open: function () {
      that.render();
    }
  };
};

// 字符常量
var STR_ELEM = 'layui-dropdown';
// var STR_HIDE = 'layui-hide';
var STR_DISABLED = 'layui-disabled';
// var STR_NONE = 'layui-none';
var STR_ITEM_UP = 'layui-menu-item-up';
var STR_ITEM_DOWN = 'layui-menu-item-down';
var STR_MENU_TITLE = 'layui-menu-body-title';
var STR_ITEM_GROUP = 'layui-menu-item-group';
var STR_ITEM_PARENT = 'layui-menu-item-parent';
var STR_ITEM_DIV = 'layui-menu-item-divider';
var STR_ITEM_CHECKED = 'layui-menu-item-checked';
var STR_ITEM_CHECKED2 = 'layui-menu-item-checked2';
var STR_MENU_PANEL = 'layui-menu-body-panel';
var STR_MENU_PANEL_L = 'layui-menu-body-panel-left';
var STR_ELEM_SHADE = 'layui-dropdown-shade';
var STR_GROUP_TITLE = '.' + STR_ITEM_GROUP + '>.' + STR_MENU_TITLE;

// 构造器
var Class = function (options) {
  var that = this;
  that.index = dropdown.index = lay.autoIncrementer('dropdown');
  that.config = $.extend({}, that.config, dropdown.config, options);
  that.stopClickOutsideEvent = $.noop;
  that.stopResizeEvent = $.noop;
  that.init();
};

// 默认配置
Class.prototype.config = {
  trigger: 'click',
  // 事件类型
  content: '',
  // 自定义菜单内容
  className: '',
  // 自定义样式类名
  style: '',
  // 设置面板 style 属性
  show: false,
  // 是否初始即显示菜单面板
  isAllowSpread: true,
  // 是否允许菜单组展开收缩
  isSpreadItem: true,
  // 是否初始展开子菜单
  data: [],
  // 菜单数据结构
  delay: [200, 300],
  // 延时显示或隐藏的毫秒数，若为 number 类型，则表示显示和隐藏的延迟时间相同，trigger 为 hover 时才生效
  shade: 0,
  // 遮罩
  accordion: false,
  // 手风琴效果，仅菜单组生效。基础菜单需要在容器上追加 'lay-accordion' 属性。
  closeOnClick: true // 面板打开后，再次点击目标元素时是否关闭面板。行为取决于所使用的触发事件类型
};

// 重载实例
Class.prototype.reload = function (options, type) {
  var that = this;
  that.config = $.extend({}, that.config, options);
  that.init(true, type);
};

// 初始化准备
Class.prototype.init = function (rerender, type) {
  var that = this;
  var options = that.config;

  // 若 elem 非唯一
  var elem = $(options.elem);
  if (elem.length > 1) {
    layui.each(elem, function () {
      dropdown.render($.extend({}, options, {
        elem: this
      }));
    });
    return that;
  }

  // 合并 lay-options 属性上的配置信息
  $.extend(options, lay.options(elem[0]));

  // 若重复执行 render，则视为 reload 处理
  if (!rerender && elem.attr(MOD_ID)) {
    var newThat = thisModule.getThis(elem.attr(MOD_ID));
    if (!newThat) return;
    return newThat.reload(options, type);
  }
  options.elem = $(options.elem);
  options.target = $('body'); // 后续考虑开放 target 元素

  // 初始化 id 属性 - 优先取 options > 元素 id > 自增索引
  options.id = 'id' in options ? options.id : elem.attr('id') || that.index;
  thisModule.that[options.id] = that; // 记录当前实例对象
  elem.attr(MOD_ID, options.id); // 目标元素已渲染过的标记

  // 初始化自定义字段名
  options.customName = $.extend({}, dropdown.config.customName, options.customName);

  // 若传入 hover，则解析为 mouseenter
  if (options.trigger === 'hover') {
    options.trigger = 'mouseenter';
  }

  // 初始即显示或者面板弹出之后执行了刷新数据
  if (options.show || type === 'reloadData' && that.mainElem && options.target.find(that.mainElem.get(0)).length) that.render(type);

  // 若面板已经打开，则无需再绑定目标元素事件，避免 render 重复执行
  if (!elem.data(MOD_INDEX_OPENED)) {
    that.events(); // 事件
  }
};

// 渲染
Class.prototype.render = function (type) {
  var that = this;
  var options = that.config;
  var customName = options.customName;

  // 默认菜单内容
  var getDefaultView = function () {
    var elemUl = $('<ul class="layui-menu layui-dropdown-menu"></ul>');
    if (options.data.length > 0) {
      eachItemView(elemUl, options.data);
    } else {
      elemUl.html('<li class="layui-menu-item-none">' + i18n.$t('dropdown.noData') + '</li>');
    }
    return elemUl;
  };

  // 遍历菜单项
  var eachItemView = function (views, data) {
    // var views = [];

    layui.each(data, function (index, item) {
      // 是否存在子级
      var isChild = item[customName.children] && item[customName.children].length > 0;
      var isSpreadItem = 'isSpreadItem' in item ? item.isSpreadItem : options.isSpreadItem;
      var title = function (title) {
        var templet = item.templet || options.templet;
        if (templet) {
          title = typeof templet === 'function' ? templet(item) : laytpl(templet).render(item);
        }
        return title;
      }(util.escape(item[customName.title]));

      // 初始类型
      var type = function () {
        if (isChild) {
          item.type = item.type || 'parent';
        }
        if (item.type) {
          return {
            group: 'group',
            parent: 'parent',
            '-': '-'
          }[item.type] || 'parent';
        }
        return '';
      }();
      if (type !== '-' && !item[customName.title] && !item[customName.id] && !isChild) return;

      //列表元素
      var viewLi = $(['<li' + function () {
        var className = {
          group: 'layui-menu-item-group' + (options.isAllowSpread ? isSpreadItem ? ' layui-menu-item-down' : ' layui-menu-item-up' : ''),
          parent: STR_ITEM_PARENT,
          '-': 'layui-menu-item-divider'
        };
        if (isChild || type) {
          return ' class="' + className[type] + '"';
        }
        return item.disabled ? ' class="' + STR_DISABLED + '"' : '';
      }() + '>',
      //标题区
      function () {
        //是否超文本
        var viewText = 'href' in item ? '<a href="' + item.href + '" target="' + (item.target || '_self') + '">' + title + '</a>' : title;

        //是否存在子级
        if (isChild) {
          return '<div class="' + STR_MENU_TITLE + '">' + viewText + function () {
            if (type === 'parent') {
              return '<i class="layui-icon layui-icon-right"></i>';
            } else if (type === 'group' && options.isAllowSpread) {
              return '<i class="layui-icon layui-icon-' + (isSpreadItem ? 'up' : 'down') + '"></i>';
            } else {
              return '';
            }
          }() + '</div>';
        }
        return '<div class="' + STR_MENU_TITLE + '">' + viewText + '</div>';
      }(), '</li>'].join(''));
      viewLi.data('item', item);

      //子级区
      if (isChild) {
        var elemPanel = $('<div class="layui-panel layui-menu-body-panel"></div>');
        var elemUl = $('<ul></ul>');
        if (type === 'parent') {
          elemPanel.append(eachItemView(elemUl, item[customName.children]));
          viewLi.append(elemPanel);
        } else {
          viewLi.append(eachItemView(elemUl, item[customName.children]));
        }
      }
      views.append(viewLi);
    });
    return views;
  };

  // 主模板
  var TPL_MAIN = ['<div class="layui-dropdown layui-border-box layui-panel layui-anim layui-anim-downbit" ' + MOD_ID + '="' + options.id + '">', '</div>'].join('');

  // 重载或插入面板内容
  var mainElem;
  var content = options.content || getDefaultView();
  var mainElemExisted = thisModule.findMainElem(options.id);
  if (type === 'reloadData' && mainElemExisted.length) {
    // 是否仅重载数据
    mainElem = that.mainElem = mainElemExisted;
    mainElemExisted.html(content);
  } else {
    // 常规渲染
    mainElem = that.mainElem = $(TPL_MAIN);
    mainElem.append(content);

    // 初始化某些属性
    mainElem.addClass(options.className);
    mainElem.attr('style', options.style);

    // 辞旧迎新
    that.remove(options.id);
    options.target.append(mainElem);
    options.elem.data(MOD_INDEX_OPENED, true); // 面板已打开的标记

    // 遮罩
    var shade = options.shade ? '<div class="' + STR_ELEM_SHADE + '" style="' + ('z-index:' + (mainElem.css('z-index') - 1) + '; background-color: ' + (options.shade[1] || '#000') + '; opacity: ' + (options.shade[0] || options.shade)) + '"></div>' : '';
    var shadeElem = $(shade);
    // 处理移动端点击穿透问题
    if (clickOrMousedown === 'touchstart') {
      shadeElem.on(clickOrMousedown, function (e) {
        e.preventDefault();
      });
    }
    mainElem.before(shadeElem);

    // 如果是鼠标移入事件，则鼠标移出时自动关闭
    if (options.trigger === 'mouseenter') {
      mainElem.on('mouseenter', function () {
        clearTimeout(that.timer);
      }).on('mouseleave', function () {
        that.delayRemove();
      });
    }
  }
  that.position(); // 定位坐标

  // 阻止全局事件
  mainElem.find('.layui-menu').on(clickOrMousedown, function (e) {
    layui.stope(e);
  });

  // 触发菜单列表事件
  mainElem.find('.layui-menu li').on('click', function (e) {
    var othis = $(this);
    var data = othis.data('item') || {};
    var isChild = data[customName.children] && data[customName.children].length > 0;
    var isClickAllScope = options.clickScope === 'all'; // 是否所有父子菜单均触发点击事件

    if (data.disabled) return; // 菜单项禁用状态

    // 普通菜单项点击后的回调及关闭面板
    if ((!isChild || isClickAllScope) && data.type !== '-') {
      var ret = typeof options.click === 'function' ? options.click(data, othis, e) : null;
      ret === false || isChild || that.remove();
      layui.stope(e);
    }
  });

  // 触发菜单组展开收缩
  mainElem.find(STR_GROUP_TITLE).on('click', function () {
    var othis = $(this);
    var elemGroup = othis.parent();
    var data = elemGroup.data('item') || {};
    if (data.type === 'group' && options.isAllowSpread) {
      thisModule.spread(elemGroup, options.accordion);
    }
  });
  that.onClickOutside();
  that.autoUpdatePosition();

  // 组件打开完毕的事件
  typeof options.ready === 'function' && options.ready(mainElem, options.elem);
};

// 位置定位
Class.prototype.position = function () {
  var that = this;
  var options = that.config;
  lay.position(options.elem[0], that.mainElem[0], {
    position: options.position,
    e: that.e,
    clickType: options.trigger === 'contextmenu' ? 'right' : null,
    align: options.align || null
  });
};

// 移除面板
Class.prototype.remove = function (id) {
  id = id || this.config.id;
  var that = thisModule.getThis(id); // 根据 id 查找对应的实例
  if (!that) return;
  var options = that.config;
  var mainElem = thisModule.findMainElem(id);
  that.stopClickOutsideEvent();
  that.stopResizeEvent();

  // 若存在已打开的面板元素，则移除
  if (mainElem[0]) {
    mainElem.prev('.' + STR_ELEM_SHADE).remove(); // 先移除遮罩
    mainElem.remove();
    options.elem.removeData(MOD_INDEX_OPENED);
    typeof options.close === 'function' && options.close(options.elem);
  }
};
Class.prototype.normalizedDelay = function () {
  var that = this;
  var options = that.config;
  var delay = [].concat(options.delay);
  return {
    show: delay[0],
    hide: delay[1] !== undefined ? delay[1] : delay[0]
  };
};

// 延迟移除面板
Class.prototype.delayRemove = function () {
  var that = this;
  // var options = that.config;
  clearTimeout(that.timer);
  that.timer = setTimeout(function () {
    that.remove();
  }, that.normalizedDelay().hide);
};

// 事件
Class.prototype.events = function () {
  var that = this;
  var options = that.config;

  // 是否鼠标移入时触发
  var isMouseEnter = options.trigger === 'mouseenter';
  var trigger = options.trigger + '.lay_dropdown_render';

  // 始终先解除上一个触发元素的事件（如重载时改变 elem 的情况）
  if (that.thisEventElem) that.thisEventElem.off(trigger);
  that.thisEventElem = options.elem;

  // 触发元素事件
  options.elem.off(trigger).on(trigger, function (e) {
    clearTimeout(that.timer);
    that.e = e;

    // 主面板是否已打开
    var opened = options.elem.data(MOD_INDEX_OPENED);

    // 若为鼠标移入事件，则延迟触发
    if (isMouseEnter) {
      if (!opened) {
        that.timer = setTimeout(function () {
          that.render();
        }, that.normalizedDelay().show);
      }
    } else {
      // 若为 click 事件，则根据主面板状态，自动切换打开与关闭
      if (options.closeOnClick && opened && options.trigger === 'click') {
        that.remove();
      } else {
        that.render();
      }
    }
    e.preventDefault();
  });

  // 如果是鼠标移入事件
  if (isMouseEnter) {
    // 执行鼠标移出事件
    options.elem.on('mouseleave', function () {
      that.delayRemove();
    });
  }
};

/**
 * 点击面板外部时的事件
 */
Class.prototype.onClickOutside = function () {
  var that = this;
  var options = that.config;
  var isCtxMenu = options.trigger === 'contextmenu';
  var isTopElem = lay.isTopElem(options.elem[0]);
  that.stopClickOutsideEvent();
  var stop = lay.onClickOutside(that.mainElem[0], function (e) {
    // 点击面板外部时的事件
    if (typeof options.onClickOutside === 'function') {
      var shouldClose = options.onClickOutside(e);
      if (shouldClose === false) return;
    }
    that.remove();
  }, {
    ignore: isCtxMenu || isTopElem ? null : [options.elem[0]],
    event: clickOrMousedown,
    capture: false,
    detectIframe: true
  });
  that.stopClickOutsideEvent = function () {
    stop();
    that.stopClickOutsideEvent = $.noop;
  };
};

/**
 * 窗口大小变化时自动更新位置
 */
Class.prototype.autoUpdatePosition = function () {
  var that = this;
  var options = that.config;
  that.stopResizeEvent();
  var windowResizeHandler = function () {
    if (that.mainElem && (!that.mainElem[0] || !that.mainElem.is(':visible'))) return;
    if (options.trigger === 'contextmenu') {
      that.remove();
    } else {
      that.position();
    }
  };
  $(window).on('resize.lay_dropdown_resize', windowResizeHandler);
  var shouldObserveResize = resizeObserver && options.trigger !== 'contextmenu';
  var triggerEl = options.elem[0];
  var contentEl = that.mainElem[0];
  if (shouldObserveResize) {
    resizeObserver.observe(triggerEl, $.proxy(that.position, that));
    resizeObserver.observe(contentEl, $.proxy(that.position, that));
  }
  that.stopResizeEvent = function () {
    $(window).off('resize.lay_dropdown_resize', windowResizeHandler);
    if (shouldObserveResize) {
      resizeObserver.unobserve(triggerEl);
      resizeObserver.unobserve(contentEl);
    }
    that.stopResizeEvent = $.noop;
  };
};

// 记录所有实例
thisModule.that = {}; // 记录所有实例对象

// 获取当前实例对象
thisModule.getThis = function (id) {
  if (id === undefined) {
    throw new Error('ID argument required');
  }
  return thisModule.that[id];
};

// 根据 id 从页面查找组件主面板元素
thisModule.findMainElem = function (id) {
  return $('.' + STR_ELEM + '[' + MOD_ID + '="' + id + '"]');
};

// 设置菜单组展开和收缩状态
thisModule.spread = function (othis, isAccordion) {
  var contentElem = othis.children('ul');
  var needSpread = othis.hasClass(STR_ITEM_UP);
  var ANIM_MS = 200;

  // 动画执行完成后的操作
  var complete = function () {
    $(this).css({
      display: ''
    }); // 剔除临时 style，以适配外部样式的状态重置;
  };

  // 动画是否正在执行
  if (contentElem.is(':animated')) return;

  // 展开
  if (needSpread) {
    othis.removeClass(STR_ITEM_UP).addClass(STR_ITEM_DOWN);
    contentElem.hide().stop().slideDown(ANIM_MS, complete);
  } else {
    // 收缩
    contentElem.stop().slideUp(ANIM_MS, complete);
    othis.removeClass(STR_ITEM_DOWN).addClass(STR_ITEM_UP);
  }

  // 手风琴
  if (needSpread && isAccordion) {
    var groupSibs = othis.siblings('.' + STR_ITEM_DOWN);
    groupSibs.children('ul').stop().slideUp(ANIM_MS, complete);
    groupSibs.removeClass(STR_ITEM_DOWN).addClass(STR_ITEM_UP);
  }
};

// 全局事件
(function () {
  var _WIN = $(window);
  var _DOC = $(document);

  // 基础菜单的静态元素事件
  var ELEM_LI = '.layui-menu:not(.layui-dropdown-menu) li';
  _DOC.on('click', ELEM_LI, function () {
    var othis = $(this);
    var parent = othis.parents('.layui-menu').eq(0);
    var isChild = othis.hasClass(STR_ITEM_GROUP) || othis.hasClass(STR_ITEM_PARENT);
    var filter = parent.attr('lay-filter') || parent.attr('id');
    var options = lay.options(this);

    // 非触发元素
    if (othis.hasClass(STR_ITEM_DIV)) return;

    // 非菜单组
    if (!isChild) {
      // 选中
      parent.find('.' + STR_ITEM_CHECKED).removeClass(STR_ITEM_CHECKED); // 清除选中样式
      parent.find('.' + STR_ITEM_CHECKED2).removeClass(STR_ITEM_CHECKED2); // 清除父级菜单选中样式
      othis.addClass(STR_ITEM_CHECKED); //添加选中样式
      othis.parents('.' + STR_ITEM_PARENT).addClass(STR_ITEM_CHECKED2); // 添加父级菜单选中样式

      options.title = options.title || $.trim(othis.children('.' + STR_MENU_TITLE).text());

      // 触发事件
      layui.event.call(this, MOD_NAME, 'click(' + filter + ')', options);
    }
  });

  // 基础菜单的展开收缩事件
  _DOC.on('click', ELEM_LI + STR_GROUP_TITLE, function () {
    var othis = $(this);
    var elemGroup = othis.parents('.' + STR_ITEM_GROUP + ':eq(0)');
    var options = lay.options(elemGroup[0]);
    var isAccordion = typeof othis.parents('.layui-menu').eq(0).attr('lay-accordion') === 'string';
    if ('isAllowSpread' in options ? options.isAllowSpread : true) {
      thisModule.spread(elemGroup, isAccordion);
    }
  });

  // 判断子级菜单是否超出屏幕
  var ELEM_LI_PAR = '.layui-menu .' + STR_ITEM_PARENT;
  _DOC.on('mouseenter', ELEM_LI_PAR, function () {
    var othis = $(this);
    var elemPanel = othis.find('.' + STR_MENU_PANEL);
    if (!elemPanel[0]) return;
    var rect = elemPanel[0].getBoundingClientRect();

    // 是否超出右侧屏幕
    if (rect.right > _WIN.width()) {
      elemPanel.addClass(STR_MENU_PANEL_L);
      // 不允许超出左侧屏幕
      rect = elemPanel[0].getBoundingClientRect();
      if (rect.left < 0) {
        elemPanel.removeClass(STR_MENU_PANEL_L);
      }
    }

    // 是否超出底部屏幕
    if (rect.bottom > _WIN.height()) {
      elemPanel.eq(0).css('margin-top', -(rect.bottom - _WIN.height() + 5));
    }
  }).on('mouseleave', ELEM_LI_PAR, function () {
    var othis = $(this);
    var elemPanel = othis.children('.' + STR_MENU_PANEL);
    elemPanel.removeClass(STR_MENU_PANEL_L);
    elemPanel.css('margin-top', 0);
  });
})();

// 关闭面板
dropdown.close = function (id) {
  var that = thisModule.getThis(id);
  if (!that) return this;
  that.remove();
  return thisModule.call(that);
};

// 打开面板
dropdown.open = function (id) {
  var that = thisModule.getThis(id);
  if (!that) return this;
  that.render();
  return thisModule.call(that);
};

// 重载实例
dropdown.reload = function (id, options, type) {
  var that = thisModule.getThis(id);
  if (!that) return this;
  that.reload(options, type);
  return thisModule.call(that);
};

// 仅重载数据
dropdown.reloadData = function () {
  var args = $.extend([], arguments);
  args[2] = 'reloadData';

  // 重载时，与数据相关的参数
  var dataParams = new RegExp('^(' + ['data', 'templet', 'content'].join('|') + ')$');

  // 过滤与数据无关的参数
  layui.each(args[1], function (key) {
    if (!dataParams.test(key)) {
      delete args[1][key];
    }
  });
  return dropdown.reload.apply(null, args);
};

// 核心入口
dropdown.render = function (options) {
  var inst = new Class(options);
  return thisModule.call(inst);
};

export { dropdown };