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 = null;

        if (header.Split != null)
        {
            var children = header.Split.Children.Count != 0 ? new ReadOnlyCollection<FrostFsObjectId>(
                    header.Split.Children.Select(x => x.ToModel()).ToList()) : null;

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

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

        return model;
    }
}