using Api.Services.Contracts.Rag;

namespace Api.Services.Rag;

public sealed class TextChunker : ITextChunker
{
    public IReadOnlyList<string> Chunk(string text, int chunkSize, int overlap)
    {
        if (string.IsNullOrWhiteSpace(text)) return [];
        chunkSize = Math.Clamp(chunkSize, 300, 3000);
        overlap = Math.Clamp(overlap, 0, chunkSize / 2);

        var chunks = new List<string>();
        var start = 0;
        while (start < text.Length)
        {
            var length = Math.Min(chunkSize, text.Length - start);
            chunks.Add(text.Substring(start, length).Trim());
            start += chunkSize - overlap;
        }

        return chunks.Where(x => !string.IsNullOrWhiteSpace(x)).ToList();
    }
}