chapter-organizer/Core/Parsers/FuzzyStudentMatcher.cs

using Core.Entities;
using FuzzySharp;

namespace Core.Parsers;

/// <summary>
/// Fuzzy-matches a CSV or pasted name to existing students.
/// </summary>
public static class FuzzyStudentMatcher
{
    public const int MatchThreshold = 90;

    public static (Student Student, int Score)? Find(ICollection<Student> students, string name)
    {
        var ranked = students
            .Select(s => (Student: s, Score: Score(s, name)))
            .Where(x => x.Score >= MatchThreshold)
            .OrderByDescending(x => x.Score)
            .ToList();

        return ranked.Count == 0 ? null : ranked[0];
    }

    public static int Score(Student student, string name)
    {
        var candidates = new[]
        {
            student.Name,
            student.FirstNameLastName,
            student.LastNameFirstName,
            student.DisplayFirstName,
            student.Nickname
        }.Where(c => !string.IsNullOrWhiteSpace(c));
        return candidates.Max(candidate => Math.Max(Fuzz.Ratio(candidate, name), Fuzz.TokenSetRatio(candidate, name)));
    }
}