using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using SabreTools.IO.Readers;
using SabreTools.Models.SeparatedValue;

namespace SabreTools.Serialization
{
    /// <summary>
    /// Serializer for separated-value variants
    /// </summary>
    public class SeparatedValue
    {
        private const int HeaderWithoutExtendedHashesCount = 14;

        private const int HeaderWithExtendedHashesCount = 17;

        /// <summary>
        /// Deserializes a separated-value variant to the defined type
        /// </summary>
        /// <param name="path">Path to the file to deserialize</param>
        /// <param name="delim">Character delimiter between values</param>
        /// <returns>Deserialized data on success, null on failure</returns>
        public static MetadataFile? Deserialize(string path, char delim)
        {
            try
            {
                using var stream = PathProcessor.OpenStream(path);
                return Deserialize(stream, delim);
            }
            catch
            {
                // TODO: Handle logging the exception
                return default;
            }
        }

        /// <summary>
        /// Deserializes a separated-value variant in a stream to the defined type
        /// </summary>
        /// <param name="stream">Stream to deserialize</param>
        /// <param name="delim">Character delimiter between values</param>
        /// <returns>Deserialized data on success, null on failure</returns>
        public static MetadataFile? Deserialize(Stream? stream, char delim)
        {
            try
            {
                // If the stream is null
                if (stream == null)
                    return default;

                // Setup the reader and output
                var reader = new SeparatedValueReader(stream, Encoding.UTF8)
                {
                    Header = true,
                    Separator = delim,
                    VerifyFieldCount = false,
                };
                var dat = new MetadataFile();

                // Read the header values first
                if (!reader.ReadHeader())
                    return null;

                dat.Header = reader.HeaderValues.ToArray();

                // Loop through the rows and parse out values
                var rows = new List<Row>();
                while (!reader.EndOfStream)
                {
                    // If we have no next line
                    if (!reader.ReadNextLine())
                        break;

                    // Parse the line into a row
                    Row? row = null;
                    if (reader.Line.Count < HeaderWithExtendedHashesCount)
                    {
                        row = new Row
                        {
                            FileName = reader.Line[0],
                            InternalName = reader.Line[1],
                            Description = reader.Line[2],
                            GameName = reader.Line[3],
                            GameDescription = reader.Line[4],
                            Type = reader.Line[5],
                            RomName = reader.Line[6],
                            DiskName = reader.Line[7],
                            Size = reader.Line[8],
                            CRC = reader.Line[9],
                            MD5 = reader.Line[10],
                            SHA1 = reader.Line[11],
                            SHA256 = reader.Line[12],
                            Nodump = reader.Line[13],
                        };

                        // If we have additional fields
                        if (reader.Line.Count > HeaderWithoutExtendedHashesCount)
                            row.ADDITIONAL_ELEMENTS = reader.Line.Skip(HeaderWithoutExtendedHashesCount).ToArray();
                    }
                    else
                    {
                        row = new Row
                        {
                            FileName = reader.Line[0],
                            InternalName = reader.Line[1],
                            Description = reader.Line[2],
                            GameName = reader.Line[3],
                            GameDescription = reader.Line[4],
                            Type = reader.Line[5],
                            RomName = reader.Line[6],
                            DiskName = reader.Line[7],
                            Size = reader.Line[8],
                            CRC = reader.Line[9],
                            MD5 = reader.Line[10],
                            SHA1 = reader.Line[11],
                            SHA256 = reader.Line[12],
                            SHA384 = reader.Line[13],
                            SHA512 = reader.Line[14],
                            SpamSum = reader.Line[15],
                            Nodump = reader.Line[16],
                        };

                        // If we have additional fields
                        if (reader.Line.Count > HeaderWithExtendedHashesCount)
                            row.ADDITIONAL_ELEMENTS = reader.Line.Skip(HeaderWithExtendedHashesCount).ToArray();
                    }
                    rows.Add(row);
                }

                // Assign the rows to the Dat and return
                dat.Row = rows.ToArray();
                return dat;
            }
            catch
            {
                // TODO: Handle logging the exception
                return default;
            }
        }
    }
}