import natural from 'natural';
const tokenizer = new natural.WordTokenizer();
const TfIdf = natural.TfIdf;
/**
* Trend Analysis Service
*/
export class TrendAnalyzer {
/**
* Extract trending topics from articles
*/
static analyzeTrends(articles: any[]): { keyword: string; count: number; trend: string }[] {
const wordCounts = new Map<string, number>();
const stopWords = new Set(['the', 'a', 'an', 'and', 'or', 'but', 'in', 'on', 'at', 'to', 'for', 'of', 'with', 'by', 'from', 'as', 'is', 'was', 'are', 'were', 'been', 'be', 'have', 'has', 'had', 'do', 'does', 'did', 'will', 'would', 'should', 'could', 'may', 'might', 'can', 'this', 'that', 'these', 'those']);
articles.forEach(article => {
const text = `${article.title} ${article.description || ''}`;
const tokens = tokenizer.tokenize(text.toLowerCase()) || [];
tokens.forEach(token => {
if (token.length > 3 && !stopWords.has(token)) {
wordCounts.set(token, (wordCounts.get(token) || 0) + 1);
}
});
});
const trends = Array.from(wordCounts.entries())
.sort((a, b) => b[1] - a[1])
.slice(0, 20)
.map(([keyword, count]) => ({
keyword,
count,
trend: count > 5 ? 'rising' : 'stable'
}));
return trends;
}
/**
* Cluster articles by topic using TF-IDF
*/
static clusterTopics(articles: any[], numClusters: number = 5): { [key: string]: any[] } {
if (articles.length === 0) return {};
const tfidf = new TfIdf();
articles.forEach(article => {
tfidf.addDocument(`${article.title} ${article.description || ''}`);
});
const clusters: { [key: string]: any[] } = {};
articles.forEach((article, idx) => {
const topTerms = tfidf.listTerms(idx).slice(0, 3);
if (topTerms.length > 0) {
const clusterKey = topTerms[0].term;
if (!clusters[clusterKey]) {
clusters[clusterKey] = [];
}
clusters[clusterKey].push(article);
}
});
return clusters;
}
/**
* Analyze time-based trends
*/
static analyzeTimeTrends(articles: any[]): { hour: number; count: number }[] {
const hourCounts = new Map<number, number>();
articles.forEach(article => {
try {
const hour = new Date(article.pub_date).getHours();
hourCounts.set(hour, (hourCounts.get(hour) || 0) + 1);
} catch { }
});
return Array.from({ length: 24 }, (_, hour) => ({
hour,
count: hourCounts.get(hour) || 0
}));
}
}
