using System;
using System.IO;
using System.Threading.Tasks;
using System.Text;
using LibAC.NBT.API;

namespace LibAC.NBT.API
{
    public static class SnbtIo
    {
        /// <summary>
        /// Writes a CompoundTag to a file in SNBT format.
        /// </summary>
        /// <param name="file">The file path to write to.</param>
        /// <param name="tag">The CompoundTag to write.</param>
        public static async Task WriteToFile(string file, CompoundTag tag)
        {
            var fileInfo = new FileInfo(file);

            if (fileInfo.Exists)
            {
                fileInfo.Delete(); // Ensure the file is reset to 0 bytes.
            }

            var builder = new StringBuilder();
            Tag.WriteStringifiedNamedTag(tag, builder, 0);

            using (var writer = new StreamWriter(file))
            {
                await writer.WriteAsync(builder.ToString());
            }
        }

        /// <summary>
        /// Reads a tag from a file in SNBT format.
        /// </summary>
        /// <param name="file">The file path to read from.</param>
        /// <returns>A Task resolving to the read Tag.</returns>
        public static async Task<Tag> ReadFromFile(string file)
        {
            var fileInfo = new FileInfo(file);
            if (!fileInfo.Exists)
            {
                throw new FileNotFoundException($"File not found: {file}");
            }

            string data;
            using (var reader = new StreamReader(file))
            {
                data = await reader.ReadToEndAsync();
            }

            var stringReader = new StringReader(data);
            Tag tag = new CompoundTag();

            try
            {
                tag = Tag.ReadStringifiedNamedTag(stringReader);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"FATAL ERROR OCCURRED AT LOCATION:\n{stringReader.GetSnapshot()}");
                Console.WriteLine(ex);
            }

            return tag;
        }

        /// <summary>
        /// Converts a CompoundTag to its SNBT string representation.
        /// </summary>
        /// <param name="tag">The CompoundTag to convert.</param>
        /// <returns>A string representing the CompoundTag in SNBT format.</returns>
        public static string WriteToString(CompoundTag tag)
        {
            var builder = new StringBuilder();
            Tag.WriteStringifiedNamedTag(tag, builder, 0);
            return builder.ToString();
        }

        /// <summary>
        /// Reads a Tag from an SNBT string.
        /// </summary>
        /// <param name="data">The SNBT string to read.</param>
        /// <returns>A Task resolving to the read Tag.</returns>
        public static Task<Tag> ReadFromString(string data)
        {
            var stringReader = new StringReader(data);
            return Task.FromResult(Tag.ReadStringifiedNamedTag(stringReader));
        }
    }
}