/**
 * KS 快手快聘 VOC 数据分析模块
 * 提供加载、筛选、统计分析功能
 */

const fs = require('fs');
const path = require('path');

const ROOT = path.resolve(__dirname, '..', '..', '..');
const RAW_DIR = path.join(ROOT, 'docs', 'raw', 'KS');

function esc(s) { return String(s ?? '').replace(/[&<>"']/g, c => ({'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;',"'":'&#39;'}[c])); }

function loadRawFiles() {
    const files = fs.readdirSync(RAW_DIR).filter(f => f.endsWith('.json') && f !== '-.json' && f !== '_merged.json' && f !== 'audit.log');
    const allItems = [];
    const byKeyword = {};
    const hypotheses = {
        'H1': 0, 'H2': 0, 'H3': 0, 'H4': 0,
        'H5': 0, 'H6': 0, 'H7': 0, 'H8': 0
    };

    const keywordHypothesisMap = {
        '快聘': ['H1', 'H2'],
        '直播带岗': ['H1', 'H2'],
        '蓝领找工作': ['H1'],
        '工资靠谱': ['H3'],
        '真实薪资': ['H3', 'H8'],
        '工资日结': ['H8'],
        '包吃包住': ['H4'],
        '当天入职': ['H5'],
        '求职被骗': ['H6'],
        '入职被坑': ['H6'],
        '黑中介': ['H7'],
        '押金不退': ['H7']
    };

    let totalVideos = 0;

    for (const file of files) {
        try {
            const filepath = path.join(RAW_DIR, file);
            const data = JSON.parse(fs.readFileSync(filepath, 'utf-8'));
            const keyword = data.keyword || path.basename(file, '.json');
            const hs = keywordHypothesisMap[keyword] || [];

            const videoCount = data.top_videos?.length || 0;
            totalVideos += videoCount;

            byKeyword[keyword] = { videos: videoCount, comments: 0, items: [] };

            const commentsObj = data.comments || {};
            let keywordCommentCount = 0;

            for (const [videoId, comments] of Object.entries(commentsObj)) {
                for (const comment of comments) {
                    const item = {
                        id: comment.id,
                        content: comment.content,
                        likes: comment.like_count || 0,
                        ip_location: comment.ip_location || '',
                        create_time: comment.create_time,
                        nickname: comment.user?.nickname || '匿名用户',
                        keyword: keyword,
                        video_id: videoId,
                        platform: 'kuaishou'
                    };
                    allItems.push(item);
                    byKeyword[keyword].items.push(item);
                    byKeyword[keyword].comments++;
                    keywordCommentCount++;

                    if (item.likes >= 3 && item.content && item.content.length >= 8) {
                        hs.forEach(h => { if (hypotheses[h] !== undefined) hypotheses[h]++; });
                    }
                }
            }

        } catch (e) {
            console.warn(`⚠️ 跳过损坏文件: ${file}`);
        }
    }

    return {
        items: allItems,
        byKeyword,
        hypotheses,
        totalVideos,
        totalComments: allItems.length,
        keywords: Object.keys(byKeyword).length,
        collectedAt: new Date().toISOString().slice(0,10)
    };
}

function getMeta(data) {
    if (!data) return {
        comments: 0, videos: 0, keywords: 0, hypotheses: {},
        collectedAt: new Date().toISOString().slice(0,10)
    };
    return {
        comments: data.totalComments,
        videos: data.totalVideos,
        keywords: data.keywords,
        hypotheses: data.hypotheses,
        collectedAt: data.collectedAt
    };
}

function getFilteredItems(data, minChars = 8, minLikes = 3) {
    if (!data || !data.items) return [];
    return data.items.filter(item => {
        const content = item.content || '';
        if (content.length < minChars) return false;
        if ((item.likes || 0) < minLikes) return false;
        return true;
    });
}

function getByHypothesis(data) {
    const keywordHypothesisMap = {
        '快聘': 'H1', '直播带岗': 'H1', '蓝领找工作': 'H1',
        '工资靠谱': 'H3', '真实薪资': 'H3',
        '工资日结': 'H8',
        '包吃包住': 'H4',
        '当天入职': 'H5',
        '求职被骗': 'H6', '入职被坑': 'H6',
        '黑中介': 'H7', '押金不退': 'H7'
    };

    const byH = { H1:[], H2:[], H3:[], H4:[], H5:[], H6:[], H7:[], H8:[] };
    const filtered = getFilteredItems(data);
    filtered.forEach(item => {
        const h = keywordHypothesisMap[item.keyword] || 'H1';
        if (byH[h]) byH[h].push(item);
    });
    return byH;
}

function getTopByKeyword(data, n = 10) {
    const filtered = getFilteredItems(data);
    const byKw = {};
    filtered.forEach(item => {
        const kw = item.keyword || '未知';
        if (!byKw[kw]) byKw[kw] = [];
        byKw[kw].push(item);
    });
    const result = [];
    Object.entries(byKw).forEach(([kw, arr]) => {
        const sorted = arr.sort((a, b) => (b.likes || 0) - (a.likes || 0)).slice(0, n);
        result.push({ keyword: kw, items: sorted, total: arr.length });
    });
    return result.sort((a, b) => b.total - a.total);
}

function getTopLiked(data, n = 20) {
    return getFilteredItems(data)
        .sort((a, b) => (b.likes || 0) - (a.likes || 0))
        .slice(0, n);
}

function getHighRiskVOC(data, n = 10) {
    const riskKeywords = ['黑中介', '押金不退', '求职被骗', '入职被坑'];
    const filtered = getFilteredItems(data);
    return filtered
        .filter(item => riskKeywords.includes(item.keyword))
        .sort((a, b) => (b.likes || 0) - (a.likes || 0))
        .slice(0, n);
}

module.exports = {
    loadRawFiles,
    getMeta,
    getFilteredItems,
    getByHypothesis,
    getTopByKeyword,
    getTopLiked,
    getHighRiskVOC
};