using System.IO.Compression;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace Compiler;

public class NubLib
{
    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        WriteIndented = true,
    };

    public static void Pack(string outputPath, string archivePath, Manifest manifest)
    {
        using var fs = new FileStream(outputPath, FileMode.Create);
        using var zip = new ZipArchive(fs, ZipArchiveMode.Create);

        var manifestEntry = zip.CreateEntry("manifest.json");
        using (var writer = new StreamWriter(manifestEntry.Open()))
        {
            var serialized = JsonSerializer.Serialize(manifest, JsonOptions);

            writer.Write(serialized);
        }

        var archiveEntry = zip.CreateEntry("lib.a");

        using var entryStream = archiveEntry.Open();
        using var fileStream = File.OpenRead(archivePath);

        fileStream.CopyTo(entryStream);
    }

    public static NubLibLoadResult Unpack(string nublibPath)
    {
        using var fs = new FileStream(nublibPath, FileMode.Open, FileAccess.Read);
        using var zip = new ZipArchive(fs, ZipArchiveMode.Read);

        var manifestEntry = zip.GetEntry("manifest.json") ?? throw new FileNotFoundException("Manifest not found in nublib", "manifest.json");

        Manifest manifest;
        using (var reader = new StreamReader(manifestEntry.Open()))
        {
            var json = reader.ReadToEnd();
            manifest = JsonSerializer.Deserialize<Manifest>(json, JsonOptions) ?? throw new InvalidDataException("Failed to deserialize manifest.json");
        }

        var archiveEntry = zip.Entries.FirstOrDefault(e => e.Name.EndsWith(".a")) ?? throw new FileNotFoundException("Archive not found in nublib", "*.a");

        string tempArchivePath = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("N") + ".a");
        using (var entryStream = archiveEntry.Open())
        using (var tempFile = File.Create(tempArchivePath))
        {
            entryStream.CopyTo(tempFile);
        }

        return new NubLibLoadResult(manifest, tempArchivePath);
    }

    public record NubLibLoadResult(Manifest Manifest, string ArchivePath);
}

public record Manifest(Dictionary<string, Manifest.Module> Modules)
{
    public static Manifest Create(ModuleGraph moduleGraph)
    {
        var modules = new Dictionary<string, Module>();

        foreach (var module in moduleGraph.GetModules())
        {
            var types = module.GetTypes().ToDictionary(x => x.Key, x => ConvertType(x.Value));
            var identifiers = module.GetIdentifiers().ToDictionary(x => x.Key, x => new Module.IdentifierInfo(x.Value.Exported, x.Value.Type));
            modules[module.Name] = new Module(types, identifiers);
        }

        return new Manifest(modules);

        static Module.TypeInfo ConvertType(Compiler.Module.TypeInfo typeInfo)
        {
            return typeInfo switch
            {
                Compiler.Module.TypeInfoStruct s => new Module.TypeInfoStruct(s.Exported, s.Packed, s.Fields.Select(x => new Module.TypeInfoStruct.Field(x.Name, x.Type)).ToList()),
                _ => throw new ArgumentOutOfRangeException(nameof(typeInfo))
            };
        }
    }


    public record Module(Dictionary<string, Module.TypeInfo> Types, Dictionary<string, Module.IdentifierInfo> Identifiers)
    {
        public record IdentifierInfo(bool Exported, NubType Type);

        [JsonDerivedType(typeof(TypeInfoStruct), "struct")]
        public abstract record TypeInfo(bool Exported);

        public record TypeInfoStruct(bool Exported, bool Packed, IReadOnlyList<TypeInfoStruct.Field> Fields) : TypeInfo(Exported)
        {
            public record Field(string Name, NubType Type);
        }
    }
}