import stringSimilarity from 'string-similarity';
/**
* Cross-Source Verification Service
*/
export class CrossVerifier {
/**
* Find similar articles across feeds
*/
static findSimilarArticles(
targetArticle: any,
allArticles: any[],
similarityThreshold: number = 0.6
): any[] {
const similar: any[] = [];
allArticles.forEach(article => {
// Skip same article
if (article.id === targetArticle.id) return;
// Calculate title similarity
const titleSimilarity = stringSimilarity.compareTwoStrings(
targetArticle.title.toLowerCase(),
article.title.toLowerCase()
);
// Calculate description similarity
let descSimilarity = 0;
if (targetArticle.description && article.description) {
descSimilarity = stringSimilarity.compareTwoStrings(
targetArticle.description.toLowerCase(),
article.description.toLowerCase()
);
}
// Combined similarity score
const similarity = (titleSimilarity * 0.7) + (descSimilarity * 0.3);
if (similarity >= similarityThreshold) {
similar.push({
...article,
similarity_score: Math.round(similarity * 100)
});
}
});
return similar.sort((a, b) => b.similarity_score - a.similarity_score);
}
/**
* Compare coverage across multiple feeds
*/
static compareCoverage(articles: any[], feedIds: string[]): any {
const coverageMap = new Map<string, Set<string>>();
// Group articles by similar content
articles.forEach(article => {
let foundGroup = false;
for (const [groupTitle, feedSet] of coverageMap.entries()) {
const similarity = stringSimilarity.compareTwoStrings(
article.title.toLowerCase(),
groupTitle.toLowerCase()
);
if (similarity > 0.7) {
feedSet.add(article.feed_id);
foundGroup = true;
break;
}
}
if (!foundGroup) {
coverageMap.set(article.title, new Set([article.feed_id]));
}
});
// Calculate coverage statistics
const coverage: any[] = [];
for (const [title, feedSet] of coverageMap.entries()) {
coverage.push({
title,
covered_by: Array.from(feedSet),
coverage_count: feedSet.size,
coverage_percentage: Math.round((feedSet.size / feedIds.length) * 100)
});
}
return {
total_stories: coverageMap.size,
coverage_details: coverage.sort((a, b) => b.coverage_count - a.coverage_count)
};
}
/**
* Detect perspective differences
*/
static detectPerspectives(similarArticles: any[]): {
common_keywords: string[];
unique_perspectives: any[];
} {
const allWords = new Set<string>();
const wordsByArticle: Map<string, Set<string>> = new Map();
similarArticles.forEach(article => {
const text = `${article.title} ${article.description || ''}`.toLowerCase();
const words = text.split(/\s+/).filter(w => w.length > 4);
words.forEach(w => allWords.add(w));
wordsByArticle.set(article.id, new Set(words));
});
// Find common keywords
const commonKeywords: string[] = [];
for (const word of allWords) {
let count = 0;
wordsByArticle.forEach(wordSet => {
if (wordSet.has(word)) count++;
});
if (count >= similarArticles.length * 0.5) {
commonKeywords.push(word);
}
}
// Find unique perspectives
const uniquePerspectives: any[] = [];
similarArticles.forEach(article => {
const words = wordsByArticle.get(article.id) || new Set();
const uniqueWords = Array.from(words).filter(w => !commonKeywords.includes(w));
uniquePerspectives.push({
feed_id: article.feed_id,
title: article.title,
unique_keywords: uniqueWords.slice(0, 5),
perspective_score: uniqueWords.length
});
});
return {
common_keywords: commonKeywords.slice(0, 10),
unique_perspectives
};
}
}
