/**
 * 区域城市级联选择
 * @author: dongjinhu(jinhu.dong@yoho.cn)
 * @date: 2016/06/30
 * @desc:
 *     1. 为了减少库的复杂度，应用层的地址接口应该统一并且固定
 * @examle:
 *     CascadingAddress({
 *         el: '#address',
 *         resources: 'areas',
 *         url: '',                       // 初始化数据请求
 *         onCreated: function () {}      // 初始化完成回调
 *     })
 */

var $ = require('yoho-jquery');

// 默认配置
var settings = {
    url: '/me/address/areas/0',
    containerClass: 'cascading-address',
    levels: 3,
    resources: 'areas',
    names: ['province', 'city', 'district'],
    indicators: ['请选择省份', '请选择城市', '请选择区/县'],
    defaultDes: '',
    ajaxSettings: {
        type: 'GET',
        url: '',
        contentType: 'application/json; charset=utf-8',
        dataType: 'json'
    }
};

// 显示或隐藏下拉区域
function toggleDistItem() {
    var $this = $(this),
        resetHeight = $this.css('height'),
        openHeight = (parseInt(resetHeight.match(/\d*/)[0], 10) + 5) + 'px',
        openAndResetHeight = (parseInt(resetHeight.match(/\d*/)[0], 10) - 5) + 'px';

    if ($this.hasClass('closed')) {
        // 如果有其他开着，先关掉
        $('.items-indicator .open').each(function() {
            $(this).find('.iconfont').replaceWith('<span class="iconfont up">&#xe60a;</span>')
             .end()
             .removeClass('open')
             .addClass('closed')
             .css({
                 height: resetHeight
             }).next().hide();
        });

        // open
        $this.find('.iconfont').replaceWith('<span class="iconfont up">&#xe609;</span>')
             .end()
             .removeClass('closed')
             .addClass('open')
             .css({
                 height: openHeight
             })
             .next()
             .show();

        // 有视觉差
        // setTimeout(function(){
        //     $('.items-panel').slideDown('fast');
        // }, 300)
    } else {
        // close
        $this.find('.iconfont').replaceWith('<span class="iconfont up">&#xe60a;</span>')
             .end()
             .removeClass('open')
             .addClass('closed')
             .css({
                 height: openAndResetHeight
             }).next().hide();
    }
}

// 设置请求URL
function setRequestUrl(config, areaId) {
    var urlArr = config.url.split(config.resources + '/');

    urlArr[1] = areaId;
    return urlArr.join(config.resources + '/');
}

// 重置下一级文本显示和值
function resetNextLevel(level, config) {
    $('#level_' + level + '_panel').empty()
        .addClass('empty')
        .text(config.defaultDes)
        .prev().find('.indicator-name')
            .text(config.indicators[config.levels - level - 1])
            .next().val('');
}

// 选择特定省份，城市，或区县
function selectDistItem(options) {
    var level = options.level,                              // 当前级别
        distElement = options.target,                       // 选择特定项
        currAreaId = distElement.attr('id').split('_')[1],  // 当前选择areaId
        distItem = $('#level_' + level + '_panel').prev(),  // 请选择...
        currPanel = options.panel,                          // 当前区域列表项
        distItemAreaId = options.distItemAreaId,            // 当前选中areaId
        config = options.config;

    var nextDistItem;

    var from;

    if (distElement.hasClass('checked')) {
        // TODO
        // distElement.removeClass('checked');
    } else {
        currPanel.find('span.checked').removeClass('checked').prev().hide();
        distElement.addClass('checked').prev().show();
        distItem.find('.indicator-name')
                .html(distElement.text())
                .next()
                .val(currAreaId);

        // 填充下一级
        if (level < 0) {
            level = distElement.parents('.items-panel').attr('id').split('_')[1];
        }

        config.url = setRequestUrl(config, currAreaId);

        // 选择之后关闭当前panel
        distItem.trigger('click');
        // 展开下一级
        nextDistItem = distItem.parent().next().find('.dist-item');
        if(nextDistItem) {
            nextDistItem.trigger('click');
        }

        // console.log('current level:', level)
        // console.log('distItemAreaId:', distItemAreaId)
        // console.log('currAreaId:', currAreaId)
        // 当前点击的和已选择的不同，再渲染下一级目录
        if (level && distItemAreaId !== currAreaId) {
            from = level;
            while (from >= 1) {
                resetNextLevel(from - 1, config);
                from--;
            }

            $(config.el).trigger('ca.afterInit', [config, level - 1]);
        }
    }
}

// 获取初始化数据
function fetchInitialData(evt, config, level) {
    // var distItemAreaId = $('.items-indicator .open input').val(),
    var ajaxSettings = $.extend({}, config.ajaxSettings, {
        url: config.url
    });

    var ulElement = $('<ul/>'),
        liElement;

    // 当前选中区域列表
    var currPanel;

    $.ajax(ajaxSettings).done(function(res) {
        // 渲染后台区域信息列表
        $(res.data).each(function(index, item) {
            liElement = $('<li/>');

            $('<span class="check-icon iconfont">&#xe60b;</span>').appendTo(liElement);
            $('<span/>', {
                class: 'dist-name',
                title: item.text,
                text: item.text,
                id: 'area_' + item.value
            }).appendTo(liElement);

            liElement.appendTo(ulElement);
        });

        // 填充下拉
        if (level >= 0) {
            currPanel = $('#level_' + level + '_panel');
            ulElement.appendTo($(config.el).find('#level_' + level + '_panel').empty().removeClass('empty'));
        }

        // 选择区域
        currPanel.off('click', '.dist-name').on('click', '.dist-name', function() {
            selectDistItem({
                level: level,
                target: $(this),
                panel: currPanel,
                distItemAreaId: currPanel.prev().find('input').val(),
                config: config
            });
        });
    }).fail(function() {
        // 如果出错，将下级所有都重置
        var from = level;

        while (from >= 0) {
            resetNextLevel(from, config);
            from--;
        }
    });
}

// 设置地址： 省，市，区县
function renderDistrict(distIds, currentLevels, config) {
    // 标识需要渲染几级
    var distLen = distIds.sort().length,
        cursor = distLen, // 游标
        areaId,           // 请求areaId
        defaultId,        // 设置areaId
        $el = $(config.el);

    // 最后一个level是0
    while (distLen > 1) {
        // 请求从array[0], 判断值从array[1]
        areaId = distIds[cursor - distLen];
        defaultId = distIds[cursor - distLen + 1];
        config.url = setRequestUrl(config, areaId);
        $el.trigger('ca.setAddr', [config, currentLevels - 1, defaultId]);
        distLen--;
        currentLevels--;
    }
}

// 设置地址
function setAddress(evt, config, level, areaId) {
    var ajaxSettings = $.extend({}, config.ajaxSettings, {
            url: config.url
        }),
        liElement,
        ulElement = $('<ul/>'),
        currPanel,
        label,
        distVal,
        distItemAreaId = $('.items-indicator .open input').val();


    $.ajax(ajaxSettings).done(function(res) {
        $(res.data).each(function(index, item) {
            liElement = $('<li/>');

            // 设置目标区域check状态
            if (item.value === areaId) {
                label = item.text;
                distVal = item.value;

                $('<span class="check-icon iconfont" style="display: inline;">&#xe60b;</span>').appendTo(liElement);
                $('<span/>', {
                    class: 'dist-name checked',
                    title: label,
                    text: label,
                    id: 'area_' + item.value
                }).appendTo(liElement);
            } else {
                $('<span class="check-icon iconfont">&#xe60b;</span>').appendTo(liElement);
                $('<span/>', {
                    class: 'dist-name',
                    title: item.text,
                    text: item.text,
                    id: 'area_' + item.value
                }).appendTo(liElement);
            }

            liElement.appendTo(ulElement);

            ulElement.appendTo($(config.el).find('#level_' + level + '_panel').empty().removeClass('empty'));
        });

        // 设置label文本 和 设置areaId
        currPanel = $('#level_' + level + '_panel');
        currPanel.prev().find('.indicator-name').text(label)
                                               .next().val(distVal);

        // 侦听选择
        currPanel.off('click', '.dist-name').on('click', '.dist-name', function() {
            selectDistItem({
                level: level,
                target: $(this),
                panel: currPanel,
                distItemAreaId: distItemAreaId,
                config: config
            });
        });

    }).fail(function() {
        // 如果出错，将下级所有都重置
        var from = level;

        while (from >= 0) {
            resetNextLevel(from, config);
            from--;
        }
    });
}

// 构造器
function CascadingAddress(options) {
    var widget = this,
        element;

    widget.config = $.extend(true, {}, settings, options); // Object.assign({}, settings, options);
    element = widget.element = $(widget.config.el);

    element.on('ca.afterInit', fetchInitialData);
    element.on('click', '.dist-item', toggleDistItem);
    element.on('ca.setAddr', setAddress);

    // 绑定自定义事件处理
    $.each(widget.config, function(key, value) {
        if ($.isFunction(value)) {
            element.on('ca.' + key, function(evt, params) {
                // 处理自定义事件
                return value(evt, element, params);
            });
        }
    });

    // 初始化
    this.init();
}

// 初始化
CascadingAddress.prototype.init = function() {
    // 配置
    var config = this.config,
        el = this.element,
        target = el.addClass(config.containerClass),
        levels = config.levels;

    // DOM相关
    var names = config.names,
        indicators = config.indicators,
        distItem,
        inputName,
        indicatorName;

    // 省份，城市，区县容器
    var distItemContainer = $('<ul class="items-indicator"/>'),
        liElement,
        distPanel;

    // ======生成DOM结构======
    while (levels--) {
        indicatorName = indicators[config.levels - levels - 1];

        // li element
        liElement = $('<li/>');

        // div element
        distItem = $('<div></div>', {
            class: 'dist-item closed'
        });

        // 标签
        $('<span/>', {
            class: 'indicator-name',
            text: indicatorName
        }).appendTo(distItem);

        // input element
        inputName = names[config.levels - levels - 1];
        $('<input/>', {
            type: 'hidden',
            name: inputName,
            id: inputName,
            value: ''
        }).appendTo(distItem);

        // icon element
        $('<span class="iconfont">&#xe60a;</span>').appendTo(distItem);

        distItem.appendTo(liElement);

        // 省份城市区县选择panel
        distPanel = $('<div/>', {
            class: 'items-panel empty',
            id: 'level_' + levels + '_panel',
            text: config.defaultDes
        });
        distPanel.appendTo(liElement);

        liElement.appendTo(distItemContainer);
    }

    distItemContainer.appendTo(target);

    // ======生成DOM结构======

    // 获取初始化数据
    el.trigger('ca.afterInit', [config, config.levels - 1]);

    // 初始化完成,提供回调执行
    el.trigger('ca.onCreated');
};

// 获取地址文本
CascadingAddress.prototype.getAreaLabels = function() {
    var el = $(this.config.el),
        result = [];

    el.find('.indicator-name').each(function() {
        if ($(this).next().val() !== '') {
            result.push($(this).text());
        }
    });

    return result.join(',');
};

// 获取地址ID
CascadingAddress.prototype.getAreaIds = function() {
    var el = $(this.config.el),
        result = [],
        target;

    el.find('input').each(function() {
        target = $(this);
        if (target.val() !== '') {
            result.push($(this).val());
        }
    });

    if (result.length) {
        return result.join(',');
    } else {
        return '';
    }
};

// 设置区域
// {
//     "province": "32",
//     "city": "3201",
//     "dist": "320102"
// }
CascadingAddress.prototype.setAddress = function(targetAddr) {
    var key,
        distIds = ['0'],  // 省份请求areaId=0
        currentLevels = $('.items-indicator>li').length,  // 目前存在几级
        config = this.config;

    if (typeof targetAddr === 'object') {
        for (key in targetAddr) {
            if (targetAddr.hasOwnProperty(key)) {
                distIds.push(targetAddr[key]);
            }
        }
        renderDistrict(distIds, currentLevels, config);
    } else if (typeof targetAddr === 'string' && targetAddr.length === 6) {
        distIds = [0, targetAddr.substr(0, 2), targetAddr.substr(0, 4), targetAddr.substr(0, 6)];
        renderDistrict(distIds, currentLevels, config);
    } else {
        console.error('target address must be a json object or areaId string');
    }
};

// 重置地址
CascadingAddress.prototype.reset = function() {
    var items = $(this.config.el).find('.items-indicator'),
        labels = this.config.indicators;

    items.each(function(index, item) {
        $(item).find('span.indicator-name').text(labels[index])
               .next().val('')
               .parent().next()
               .find('span.checked').removeClass('checked').prev().hide();
    });
};

module.exports = function(options) {
    return new CascadingAddress(options);
};