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

using FrostFS.SDK.ClientV2;
using FrostFS.SDK.ClientV2.Mappers.GRPC;
using FrostFS.SDK.Cryptography;

using Google.Protobuf;

namespace FrostFS.SDK;

public class FrostFsContainerInfo
{
    private Container.Container.Types.Attribute[]? grpsAttributes;
    private ReadOnlyCollection<FrostFsAttributePair>? attributes;
    private FrostFsPlacementPolicy? placementPolicy;
    private Guid? nonce;

    private Container.Container? container;

    public FrostFsContainerInfo(
        FrostFsPlacementPolicy placementPolicy,
        FrostFsAttributePair[]? attributes = null,
        FrostFsVersion? version = null,
        FrostFsOwner? owner = null,
        Guid? nonce = null)
    {
        this.placementPolicy = placementPolicy;
        Version = version;
        Owner = owner;
        this.nonce = nonce;

        if (attributes != null)
            this.attributes = new ReadOnlyCollection<FrostFsAttributePair>(attributes);
    }

    internal FrostFsContainerInfo(Container.Container container)
    {
        this.container = container;
    }

    public Guid Nonce
    {
        get
        {
            nonce ??= container?.Nonce != null ? container.Nonce.ToUuid() : Guid.NewGuid();
            return nonce.Value;
        }
    }

    public FrostFsPlacementPolicy? PlacementPolicy
    {
        get
        {
            placementPolicy ??= container?.PlacementPolicy?.ToModel();
            return placementPolicy;
        }
    }

    public ReadOnlyCollection<FrostFsAttributePair>? Attributes
    {
        get
        {
            if (attributes == null && grpsAttributes != null)
                attributes = new ReadOnlyCollection<FrostFsAttributePair>(grpsAttributes.Select(a => new FrostFsAttributePair(a.Key, a.Value)).ToList());

            return attributes;
        }
    }

    public FrostFsVersion? Version { get; private set; }

    public FrostFsOwner? Owner { get; private set; }

    internal Container.Container.Types.Attribute[]? GetGrpsAttributes()
    {
        grpsAttributes ??= Attributes?
            .Select(a => new Container.Container.Types.Attribute { Key = a.Key, Value = a.Value })
            .ToArray();

        return grpsAttributes;
    }

    internal Container.Container GetContainer()
    {
        if (this.container == null)
        {
            if (PlacementPolicy == null)
            {
                throw new ArgumentNullException("PlacementPolicy is null");
            }

            this.container = new Container.Container()
            {
                PlacementPolicy = PlacementPolicy.Value.GetPolicy(),
                Nonce = ByteString.CopyFrom(Nonce.ToBytes()),
                OwnerId = Owner?.OwnerID,
                Version = Version?.Version
            };

            var attribs = GetGrpsAttributes();
            if (attribs != null)
                this.container.Attributes.AddRange(attribs);
        }

        return this.container;
    }
}