// ==UserScript==
// @name         Google Search sidebar
// @namespace    http://tampermonkey.net/
// @version      0.1.3
// @description  Add a sidebar on Google search for easier information filtering
// @author       Kamiya Minoru
// @match        https://www.google.com/*
// @match        https://www.google.com.tw/*
// @match        https://www.google.co.jp/*
// @grant        none
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    const userLang = navigator.language || navigator.userLanguage;

    const i18n = {
        'zh-TW': {
            languageSection: '語言過濾',
            timeSection: '時間過濾',
            advancedSearch: '進階搜尋',
            languages: {
                any: '不限語言搜尋',
                zhTW: '以繁體中文搜尋',
                zh: '以中文搜尋',
                ja: '以日文搜尋',
                en: '以英文搜尋'
            },
            times: {
                any: '不限時間',
                hour: '過去1小時',
                day: '過去24小時',
                week: '過去7天',
                month: '過去1個月',
                months3: '過去3個月',
                year: '過去1年'
            }
        },
        'ja': {
            languageSection: '言語フィルター',
            timeSection: '期間フィルター',
            advancedSearch: '検索オプション',
            languages: {
                any: '言語指定なし',
                zhTW: '繁体中国語で検索',
                zh: '中国語で検索',
                ja: '日本語で検索',
                en: '英語で検索'
            },
            times: {
                any: '期間指定なし',
                hour: '1時間以内',
                day: '24時間以内',
                week: '1週間以内',
                month: '1か月以内',
                months3: '3か月以内',
                year: '1年以内'
            }
        },
        'en': {
            languageSection: 'Language Filter',
            timeSection: 'Time Filter',
            advancedSearch: 'Advanced Search',
            languages: {
                any: 'Any Language',
                zhTW: 'Traditional Chinese Only',
                zh: 'Chinese Only',
                ja: 'Japanese Only',
                en: 'English Only'
            },
            times: {
                any: 'Any Time',
                hour: 'Past Hour',
                day: 'Past 24 Hours',
                week: 'Past Week',
                month: 'Past Month',
                months3: 'Past 3 Months',
                year: 'Past Year'
            }
        }
    };

    function getLocale() {
        if (i18n[userLang]) {
            return i18n[userLang];
        }

        const primaryLang = userLang.split('-')[0];
        if (i18n[primaryLang]) {
            return i18n[primaryLang];
        }

        return i18n['en'];
    }

    const locale = getLocale();

    const languageFilters = [
        { text: locale.languages.any, param: '' },
        { text: locale.languages.zhTW, param: '&lr=lang_zh-TW' },
        { text: locale.languages.zh, param: '&lr=lang_zh' },
        { text: locale.languages.ja, param: '&lr=lang_ja' },
        { text: locale.languages.en, param: '&lr=lang_en' }
    ];

    const timeFilters = [
        { text: locale.times.any, param: '' },
        { text: locale.times.hour, param: '&tbs=qdr:h' },
        { text: locale.times.day, param: '&tbs=qdr:d' },
        { text: locale.times.week, param: '&tbs=qdr:w' },
        { text: locale.times.month, param: '&tbs=qdr:m' },
        { text: locale.times.months3, param: '&tbs=qdr:m3' },
        { text: locale.times.year, param: '&tbs=qdr:y' }
    ];

    function createAdvancedSearchLink() {
        const link = document.createElement('a');
        link.textContent = locale.advancedSearch;
        link.href = getAdvancedSearchUrl();
        link.style.cssText = `
            display: block;
            color: #1a73e8;
            text-decoration: none;
            font-size: 13px;
            padding: 8px;
            margin-top: 10px;
            background: #f8f9fa;
            border-radius: 8px;
            text-align: center;
            transition: background-color 0.2s;
        `;
        link.addEventListener('mouseover', () => {
            link.style.backgroundColor = '#e8f0fe';
        });
        link.addEventListener('mouseout', () => {
            link.style.backgroundColor = '#f8f9fa';
        });
        return link;
    }

    function createFilterSection(title, filters) {
        const section = document.createElement('div');
        section.style.cssText = `
            margin: 10px 0;
            padding: 8px;
            background: #f8f9fa;
            border-radius: 8px;
        `;

        const titleElement = document.createElement('h3');
        titleElement.textContent = title;
        titleElement.style.cssText = `
            margin: 0 0 8px 0;
            font-size: 13px;
            color: #202124;
            font-weight: 500;
        `;
        section.appendChild(titleElement);

        const linkContainer = document.createElement('div');
        linkContainer.style.cssText = `
            display: flex;
            flex-direction: column;
            gap: 6px;
        `;

        filters.forEach(filter => {
            const link = document.createElement('a');
            link.textContent = filter.text;
            link.href = getCurrentUrlWithParam(filter.param);
            link.style.cssText = `
                color: #1a73e8;
                text-decoration: none;
                font-size: 12px;
                padding: 3px 6px;
                border-radius: 4px;
                transition: background-color 0.2s;
            `;
            link.addEventListener('mouseover', () => {
                link.style.backgroundColor = '#e8f0fe';
            });
            link.addEventListener('mouseout', () => {
                link.style.backgroundColor = 'transparent';
            });
            linkContainer.appendChild(link);
        });

        section.appendChild(linkContainer);
        return section;
    }

    function getCurrentUrlWithParam(param) {
        const url = new URL(window.location.href);

        // Remove existing language or time parameters
        url.searchParams.delete('lr');
        url.searchParams.delete('tbs');

        // Add new parameters
        if (param) {
            const cleanParam = param.startsWith('&') ? param.substring(1) : param;
            const [key, value] = cleanParam.split('=');
            url.searchParams.set(key, value);
        }

        return url.toString();
    }

    function getAdvancedSearchUrl() {
        const url = new URL('https://www.google.com/advanced_search');
        const currentParams = new URLSearchParams(window.location.search);

        // Append current search parameters to the advanced search URL
        currentParams.forEach((value, key) => {
            url.searchParams.set(key, value);
        });

        return url.toString();
    }

    function addFiltersToPage() {
        const searchResults = document.getElementById('search');
        if (!searchResults) return;

        const sidebar = document.createElement('div');
        sidebar.style.cssText = `
            position: fixed;
            top: 10px;
            left: 10px;
            width: 160px;
            z-index: 1000;
        `;

        sidebar.appendChild(createFilterSection(locale.languageSection, languageFilters));
        sidebar.appendChild(createFilterSection(locale.timeSection, timeFilters));
        sidebar.appendChild(createAdvancedSearchLink());

        document.body.appendChild(sidebar);
    }

    const observer = new MutationObserver((mutations, obs) => {
        const searchResults = document.getElementById('search');
        if (searchResults) {
            addFiltersToPage();
            obs.disconnect();
        }
    });

    observer.observe(document.body, {
        childList: true,
        subtree: true
    });
})();