export class SimilarityCalculator {
static calculateSimilarityScore(original: string, candidate: string): number {
if (original === candidate) return 1.0;
const originalLower = original.toLowerCase();
const candidateLower = candidate.toLowerCase();
if (candidateLower.includes(originalLower) || originalLower.includes(candidateLower)) {
return 0.9;
}
const distance = this.levenshteinDistance(originalLower, candidateLower);
const maxLength = Math.max(original.length, candidate.length);
return Math.max(0, 1 - (distance / maxLength));
}
private static levenshteinDistance(str1: string, str2: string): number {
if (str1.length === 0) return str2.length;
if (str2.length === 0) return str1.length;
const matrix: number[][] = [];
for (let i = 0; i <= str2.length; i++) {
matrix[i] = [i];
}
for (let j = 0; j <= str1.length; j++) {
matrix[0][j] = j;
}
for (let i = 1; i <= str2.length; i++) {
for (let j = 1; j <= str1.length; j++) {
if (str2.charAt(i - 1) === str1.charAt(j - 1)) {
matrix[i][j] = matrix[i - 1][j - 1];
} else {
matrix[i][j] = Math.min(
matrix[i - 1][j - 1] + 1,
matrix[i][j - 1] + 1,
matrix[i - 1][j] + 1
);
}
}
}
return matrix[str2.length][str1.length];
}
}
