namespace AdventOfCode2024.Input.Parsers;

public abstract class TextLineParser<U> : IParser<IList<U>> where U : notnull
{
    /// <summary>
    /// Parses a line to the given Entity type
    /// </summary>
    /// <param name="line">Line in the form of a string</param>
    /// <returns>The parsed entity</returns>
    protected abstract U ParseLine(string line);
    
    /// <inheritdoc />
    public async Task<IList<U>> ParseAsync(Stream input)
    {
        using StreamReader reader = new StreamReader(input);
        List<U> entities = [];

        while (!reader.EndOfStream)
        {
            string? line = await reader.ReadLineAsync();
            if (line != null)
            {
                entities.Add(ParseLine(line)); 
            }
        }

        return entities;
    }
}