using System.Threading;
using System.Threading.Tasks;
using game.PlayerDataStorage;

internal static class KVMgr
{
    internal static PlayerKVKeyReadResult ReadKV(PlayerKVGameSessionHandle handle, string key)
    {
        if (PlayerKVGameLoadGuard.Reject(PlayerKVGuardPoint.ReadLocal))
            return new PlayerKVKeyReadResult(PlayerKVKeyReadError.LoadGuardActive, handle);
        if (handle == null || !KVSnapshot.ValidKey(key))
            return new PlayerKVKeyReadResult(PlayerKVKeyReadError.InvalidInput, handle);
        var read = handle.ReadLocalSnapshot();
        if (!read.Success)
            return new PlayerKVKeyReadResult(read.Error == PlayerKVLocalReadError.StaleOrClosing
                ? PlayerKVKeyReadError.StaleOrClosing : PlayerKVKeyReadError.NotReady, handle);
        var found = read.Data.TryGetValue(key, out var value);
        return new PlayerKVKeyReadResult(PlayerKVKeyReadError.None, handle, found, value);
    }

    internal static PlayerKVEditResult WriteKV(PlayerKVGameSessionHandle handle,
        string key, string value, bool remoteStore = true)
    {
        if (PlayerKVGameLoadGuard.Reject(PlayerKVGuardPoint.Update))
            return new PlayerKVEditResult(new PlayerKVStateResult(PlayerKVChangeError.Blocked));
        if (handle == null)
            return new PlayerKVEditResult(new PlayerKVStateResult(PlayerKVChangeError.Validation));
        return handle.Update(key, value, remoteStore);
    }

    internal static Task<PlayerKVFlushResult> FlushKVAsync(PlayerKVGameSessionHandle handle,
        CancellationToken waitToken = default)
    {
        if (PlayerKVGameLoadGuard.Reject(PlayerKVGuardPoint.Sync))
            return Task.FromResult(new PlayerKVFlushResult(0, 0, 1, 0, PlayerKVError.Cancelled,
                handle == null ? PlayerKVSyncStatus.NotLoaded : handle.Status));
        if (handle == null)
            return Task.FromResult(new PlayerKVFlushResult(0, 0, 1, 0, PlayerKVError.Validation, PlayerKVSyncStatus.NotLoaded));
        return handle.FlushAsync(waitToken);
    }

    internal static Task<PlayerKVTicketResult> WaitForKVTicketAsync(PlayerKVGameSessionHandle handle,
        PlayerKVSyncTicket ticket, CancellationToken waitToken = default)
    {
        if (PlayerKVGameLoadGuard.Reject(PlayerKVGuardPoint.Sync))
            return Task.FromResult(new PlayerKVTicketResult(PlayerKVTicketStatus.Blocked, PlayerKVError.Cancelled,
                handle == null ? PlayerKVSyncStatus.NotLoaded : handle.Status));
        if (handle == null)
            return Task.FromResult(new PlayerKVTicketResult(PlayerKVTicketStatus.Blocked, PlayerKVError.Validation, PlayerKVSyncStatus.NotLoaded));
        return handle.WaitForTicketAsync(ticket, waitToken);
    }
}