// ==UserScript==
// @name      NGA Filter
// @namespace https://greasyfork.org/users/263018
// @version    0.4
// @author     snyssss
// @description troll must die
// @match        *bbs.nga.cn/thread.php?fid=*
// @match        *bbs.nga.cn/read.php?tid=*
// @match        *ngabbs.com/thread.php?fid=*
// @match        *ngabbs.com/read.php?tid=*
// @grant       GM_registerMenuCommand
// @grant       GM_unregisterMenuCommand
// @noframes
// @downloadURL none
// ==/UserScript==

(function () {
    'use strict';

    const dataKey = 'troll_data';
    const modeKey = 'troll_mode';

    const keyword = [
        '魔兽', '拼多多'
    ];

    let filterMode = ~~localStorage.getItem(modeKey);

    let trollMap = (function () {
        try {
            return JSON.parse(localStorage.getItem(dataKey)) || {};
        } catch (e) {
            localStorage.setItem(dataKey, '{}');
        }
        return {};
    })();

    const isTroll = function (uid) {
        uid = ~~uid;
        if (uid) {
            return trollMap[uid];
        }
        return false;
    };

    const isMatch = function (text) {
        for (var i in keyword) {
            if (text.search(keyword[i]) >= 0) {
                return true;
            }
        }
        return false;
    };

    const toggleTroll = function (uid) {
        uid = ~~uid;
        if (uid) {
            if (trollMap[uid]) {
                delete trollMap[uid];
            } else {
                trollMap[uid] = true;
            }
            localStorage.setItem(dataKey, JSON.stringify(trollMap));
        }
    };

    const getUID = function (e) {
        let ele = e.getElementsByClassName('author')[0];
        if (ele) {
            return ele.search.match(/uid=(\S*)/)[1];
        }
    };

    const getLink = function (e) {
        let ele = e.getElementsByClassName('topic')[0];
        ele.hide = function () {
            if (filterMode) {
                e.remove();
            }else{
                ele.style.textDecoration = 'line-through';
            }
        }
        return ele;
    };

    const getToggleButton = function (e) {
        let ele = e.getElementsByClassName('author')[0].nextElementSibling;
        if (ele.nextElementSibling) {
            ele = ele.nextElementSibling;
        }
        let uid = ~~ele.text;
        if (uid) {
            if (isTroll(uid)) {
                ele.style.background = '#CB4042';
            } else {
                ele.style.background = '#AAA';
            }
            return ele;
        }
        else {
            ele.onclick = null;
        }
    };

    const getAvatar = function (e) {
        let ele = e.getElementsByClassName('avatar')[0] || { style: { display: '' } };
        ele.show = function () {
            ele.style.display = '';
        }
        ele.hide = function () {
            ele.style.display = 'none';
        }
        return ele;
    };

    const getContent = function (e) {
        let uid = getUID(e);
        let name = '$troll_' + uid;
        let ele = e.getElementsByClassName('postcontent')[0] || { innerHTML: '' };
        ele.content = ele.content || ele.innerHTML;
        ele.show = function () {
            if (filterMode) {
                e.style.display = '';
            } else {
                ele.innerHTML = ele.content;
            }
        }
        ele.hide = function () {
            if (filterMode) {
                e.style.display = 'none';
            } else {
                ele.innerHTML =
                    '<div class="lessernuke" style="background: #81C7D4; border-color: #66BAB7;">' +
                    '<span class="crimson">Troll must die.</span> ' +
                    '<a href="javascript:void(0)" onclick="var x = document.getElementsByName(&quot;' + name + '&quot;);for(var i=0;i<x.length;i++){x[i].style.display=&quot;&quot;}">点击查看</a>' +
                    '<div style="display:none" name="' + name + '">' + ele.content + '</div>' +
                    '</div>';
            }
        }
        return ele;
    };

    const observerElements = [
        (function () {
            let container = document.getElementById('topicrows');
            let func = function (e) {
                if (e.tagName == 'SCRIPT') return;
                let uid = getUID(e);
                let link = getLink(e);
                if (isTroll(uid) ||
                    isMatch(link.innerHTML)) {
                    link.hide();
                }
            }
            return [
                container,
                func
            ]
        })(),
        (function () {
            let container = document.getElementById('m_posts_c');
            let func = function (e) {
                if (e.tagName == 'SCRIPT') return;
                let uid = getUID(e);
                let toggle = getToggleButton(e);
                if (toggle) {
                    toggle.onclick = function () {
                        toggleTroll(uid);
                        container.refilter();
                    };
                } else {
                    return;
                }
                let avatar = getAvatar(e);
                let content = getContent(e);
                if (isTroll(uid)) {
                    avatar.hide();
                    content.hide();
                }
                else {
                    avatar.show();
                    content.show();
                }
            }
            return [
                container,
                func
            ]
        })()
    ];

    [].slice.call(observerElements).forEach(function (e) {
        if (!e[0]) return;

        e[0].refilter = function () {
            [].slice.call(e[0].children).forEach(function (c) {
                e[1](c);
            });
        }

        e[0].refilter();

        let observer = new MutationObserver(function (mutations) {
            mutations.forEach(function (mutation) {
                if (mutation.addedNodes.length) {
                    e[1](mutation.addedNodes[0]);
                }
            });
        });

        observer.observe(e[0], {
            childList: true
        });
    });

    if (filterMode) {
        GM_registerMenuCommand('过滤模式：删除', () => {
            localStorage.setItem(modeKey, 0);
            location.reload();
        });
    } else {
        GM_registerMenuCommand('过滤模式：标记', () => {
            localStorage.setItem(modeKey, 1);
            location.reload();
        });
    }
})();