namespace ParadoxSaveParser.Lib;

/// <summary>A literal key, matched byte for byte.</summary>
internal sealed class ExactMatchExpression : ISearchExpression
{
    public string Key { get; }

    // the key as it appears in the save, so matching needs no encoding at all
    public byte[] KeyBytes { get; private set; }
    public ISearchExpression? Next { get; }

    public ExactMatchExpression(string key, Encoding encoding, ISearchExpression? next)
    {
        Key = key;
        Next = next;
        KeyBytes = encoding.GetBytes(key);
    }

    public bool DoesMatch(MatchCandidate candidate, out ISearchExpression? nextSearchExpression)
    {
        // comparing bytes keeps the candidate's key from becoming a string
        if (candidate.Key.SequenceEqual(KeyBytes))
        {
            nextSearchExpression = Next;
            return true;
        }

        nextSearchExpression = null;
        return false;
    }

    public void ReEncode(Encoding encoding)
    {
        KeyBytes = encoding.GetBytes(Key);
        Next?.ReEncode(encoding);
    }
}