using System.Text;

namespace Domain;

public class ExpIniFileGenerator(uint rowCount, uint oddColumnCount, uint evenColumnCount)
{
    private const string _lineEnding = "\r\n";

    public string Generate(IEnumerable<FrameExpInfo> frameInfos)
    {
        var groups = frameInfos
            .DistinctBy(q => new {q.Row, q.Column})
            .GroupBy(q => q.Row, (row, columns) => new { Row = row, Columns = columns });
        var sb = new StringBuilder();
        AppendLine(sb, oddColumnCount.ToString());
        AppendLine(sb, evenColumnCount.ToString());
        AppendLine(sb, rowCount.ToString());
        
        foreach (var row in groups.OrderBy(q => q.Row))
        {
            bool? isPreviousContainAnything = null;
            var stateAccumulator = 0u;
            foreach (var column in row.Columns)
            {
                isPreviousContainAnything ??= column.IsContainAnything;

                if (isPreviousContainAnything == column.IsContainAnything)
                {
                    stateAccumulator++;
                }
                else
                {
                    sb.Append(GetExpValue(isPreviousContainAnything.Value, stateAccumulator));
                    stateAccumulator = 0u;
                    isPreviousContainAnything = column.IsContainAnything;
                }
            }

            if (stateAccumulator > 0 && isPreviousContainAnything.HasValue)
            {
                sb.Append(GetExpValue(isPreviousContainAnything.Value, stateAccumulator));
            }
            sb.Append(_lineEnding);
        }
        
        return sb.ToString();
    }

    private static void AppendLine(StringBuilder sb, string text)
    {
        sb.Append(text);
        sb.Append(_lineEnding);
    }

    private static string GetExpValue(bool isContainAnything, uint accumulator)
    {
        return string.Concat(accumulator.ToString(), isContainAnything ? 'e' : 'z');
    }

    public class FrameExpInfo
    {
        public uint Row { get; init; }
        public uint Column { get; init; }
        public bool IsContainAnything { get; set; }
    }
}