using System;
using System.Collections.ObjectModel;
using System.Linq;

using FrostFS.Object;
using FrostFS.SDK.Cryptography;

namespace FrostFS.SDK.Client.Mappers.GRPC;

public static class ObjectHeaderMapper
{
    public static FrostFsObjectHeader ToModel(this Header header)
    {
        if (header is null)
        {
            throw new ArgumentNullException(nameof(header));
        }

        var objTypeName = header.ObjectType switch
        {
            ObjectType.Regular => FrostFsObjectType.Regular,
            ObjectType.Lock => FrostFsObjectType.Lock,
            ObjectType.Tombstone => FrostFsObjectType.Tombstone,
            _ => throw new ArgumentException($"Unknown ObjectType. Value: '{header.ObjectType}'.")
        };

        FrostFsSplit? split = header!.Split != null
            ? header.Split.ToModel()
            : null;

        var model = new FrostFsObjectHeader(
            new FrostFsContainerId(Base58.Encode(header.ContainerId.Value.Span)),
            objTypeName,
            [.. header.Attributes.Select(attribute => attribute.ToModel())],
            split,
            header.OwnerId.ToModel(),
            header.Version.ToModel())
        {
            PayloadLength = header.PayloadLength,
        };

        return model;
    }

    public static FrostFsSplit ToModel(this Header.Types.Split split)
    {
        if (split is null)
        {
            throw new ArgumentNullException(nameof(split));
        }

        var children = split!.Children.Count != 0
            ? new ReadOnlyCollection<FrostFsObjectId>([.. split.Children.Select(x => x.ToModel())])
            : null;

        return new FrostFsSplit(new SplitId(split.SplitId.ToUuid()),
                        split.Previous?.ToModel(),
                        split.Parent?.ToModel(),
                        split.ParentHeader?.ToModel(),
                        null,
                        children);
    }
}