// ==UserScript==
// @name         京东单价助手
// @namespace    http://greasyfork.org/
// @version      1.06
// @description  京东商品列表页面的增强程序，增强了显示单价功能，帮助你在京东找到最便宜的商品
// @author       Yarmu
// @match        *://search.jd.com/*
// @match        *://list.jd.com/*
// @match        *://item.jd.com/*
// @grant        none
// @supportURL     https://greasyfork.org/zh-CN/scripts/30522-%E4%BA%AC%E4%B8%9C%E5%8D%95%E4%BB%B7%E5%8A%A9%E6%89%8B
// @downloadURL none
// ==/UserScript==

(function() {
    var host = window.location.host.toLowerCase();
    if (host === 'list.jd.com' || host === 'search.jd.com') {
        addPriceTipListener('.p-price', addListPriceTip, 1000);
    } else if (host === 'item.jd.com') {
        addPriceTipListener('.p-price', addItemPriceTip);
        addPriceTipListener('.p-price-plus', addItemPriceTip);
    }
})();

function addPriceTipListener(tag, func, time) {
    var onModifiedFunc = function() {
        $(this).unbind("DOMSubtreeModified");
        func.call(this);
        $(this).bind("DOMSubtreeModified", onModifiedFunc);
    };
    var eachCallFunc = function() {
        $(tag).each(function() {
            if (!$(this).attr('priceTip')) {
                $(this).attr('priceTip', '1');
                onModifiedFunc.call(this);
            }
        });
    };
    eachCallFunc();
    if (time) {
        setInterval(eachCallFunc, time);
    }
}

function addListPriceTip() {
    var priceItem = $(this).find('strong i');
    var price = getFloat(priceItem.text());
    if (isNaN(price)) {
        priceItem = $(this).find('strong span');
        price = getFloat(priceItem.text());
        if (isNaN(price)) {
            priceItem = $(this).find('strong');
            price = getFloat(priceItem.text());
            if (isNaN(price)) {
                priceItem = $(this);
                price = getFloat(priceItem.text());
            }
        }
    }
    if (isNaN(price)) return;

    var title = null;
    var index = 0;
    $(this).parent().find('.p-scroll .ps-wrap .ps-main .ps-item a').each(function(idx) {
        if ($(this).attr('class') === 'curr' && $(this).attr('title')) {
            title = $(this).attr('title').trim();
            index = idx;
            return false;
        }
    });
    var unit = getUnit(title, price);
    if (unit === null && index === 0) {
        title = $(this).parent().find('.p-name a em').text().trim();
        if (!title) {
            title = $(this).parent().find('.p-name a').text().trim();
        }
        unit = getUnit(title, price);
    }
    if (unit === null) return;

    var htm = price + ' (' + unit.price + '/' + unit.unit + ')';
    title += ' (' + unit.capacity + unit.unit + ')';
    priceItem.text(htm);
    var tipItem = $(this).parent().find('.p-name a');
    setTimeout(function() {
        tipItem.attr('title', title);
    }, 1000);
}

function addItemPriceTip() {
    var priceItem = $(this).find('.price');
    var price = getFloat(priceItem.text());
    if (isNaN(price)) return;
    var title = $('.sku-name').text().trim();
    var unit = getUnit(title, price);
    if (unit === null) return;
    var htm = ' (' + unit.price + '/' + unit.unit + ')';
    title = ' (' + unit.capacity + unit.unit + ')';
    priceItem.append(htm);
    if (!window.hasAddItemPriceTip) {
        window.hasAddItemPriceTip = true;
        setTimeout(function() {
            $('#summary-weight .dd').append(title);
        }, 1000);
    }
}

function getUnit(title, price) {
    if (!title) return null;
    if (price <= 0) return null;
    var name = title.replace(/[(（][^)）]+[)）]/ig, '');
    var reg1 = /\b((\d+)\s*[个只瓶罐桶条包袋件盒箱组]?\s*[*x×]\s*)(\d+\.?\d*?)\s*(g|kg|ml|l|千克|克|斤|公斤|毫升|升)/ig;
    var reg2 = /\b(\d+\.?\d*?)\s*(g|kg|ml|l|千克|克|斤|公斤|毫升|升)\/?(\s*[\u4e00-\u9fa5]*\s*[*x×]\s*(\d+))?/ig;
    var pCap = 3, pUnit = 4, pCount = 1;
    var reg = reg1;
    if (!reg.test(name)) {
        pCap = 1; pUnit = 2; pCount = 4;
        reg = reg2;
        if (!reg.test(name)) {
            name = title;
            pCap = 3; pUnit = 4; pCount = 1;
            reg = reg1;
            if (!reg.test(name)) {
                pCap = 1; pUnit = 2; pCount = 4;
                reg = reg2;
            }
        }
    }
    reg.lastIndex = 0;

    var match = null;
    var cap = 0;
    var un = '';
    var isOnlyOne = !/[+＋送和]/i.test(name);
    while ((match = reg.exec(name))) {
        var capacity = parseFloat(match[pCap]);
        if (match.length > 4 && match[pCount]) {
            capacity *= parseInt(match[pCount]);
        }
        if (capacity <= 0) {
            continue;
        }
        var unit = match[pUnit].toLowerCase();

        if (unit === 'g' || unit === '克') {
            capacity /= 1000;
            unit = 'kg';
        } else if (unit === '千克' || unit === '公斤') {
            unit = 'kg';
        } else if (unit === '斤') {
            capacity /= 2;
            unit = 'kg';
        } else if (unit === 'ml' || unit === '毫升') {
            capacity /= 1000;
            unit = 'L';
        } else if (unit === 'l' || unit === '升') {
            unit = 'L';
        }
        if (un === '' || un === unit) {
            un = unit;
            cap += capacity;
        }
        if (isOnlyOne) {
            break;
        }
    }

    if (cap > 0) return {
        capacity: Math.round(cap * 10000) / 10000,
        unit: un,
        price: Math.round(parseFloat(price) / cap * 100) / 100
    };
    else return null;
}

function getFloat(str) {
    str = str.replace('￥','').trim();
    if (!/^\d+\.?\d*$/.test(str)) return NaN;
    return parseFloat(str);
}