using System;
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Pithos.Interfaces
{
    [ContractClass(typeof(ICloudClientContract))]
    public interface ICloudClient
    {
        string ApiKey { get; set; }
        string UserName { get; set; }
        Uri StorageUrl { get; set; }
        string Token { get; set; }
        bool UsePithos { get; set; }
        void Authenticate(string userName,string apiKey);
        Uri Proxy { get; set; }
        double DownloadPercentLimit { get; set; }
        double UploadPercentLimit { get; set; }
        string AuthenticationUrl { get; set; }


        IList<ContainerInfo> ListContainers();
        IList<ObjectInfo> ListObjects(string container,DateTime? since=null);
        IList<ObjectInfo> ListObjects(string container, string folder, DateTime? since = null); 
        bool ContainerExists(string container);
        ContainerInfo GetContainerInfo(string container);
        void CreateContainer(string container);
        void DeleteContainer(string container);
        
        Task GetObject(string container, string objectName, string fileName);
        Task PutObject(string container, string objectName, string fileName, string hash = null);
        void DeleteObject(string container, string objectName);
        void MoveObject(string sourceContainer, string oldObjectName, string targetContainer,string newObjectName);
        bool ObjectExists(string container,string objectName);
        ObjectInfo GetObjectInfo(string container, string objectName);
        void CreateFolder(string container, string folder);


    }


    [ContractClassFor(typeof(ICloudClient))]
    public abstract class ICloudClientContract:ICloudClient
    {
        public string ApiKey { get; set; }
        public string UserName { get; set; }
        public Uri StorageUrl { get; set; }
        public string Token { get; set; }
        public Uri Proxy { get; set; }
        public double DownloadPercentLimit { get; set; }
        public double UploadPercentLimit { get; set; }

        public string AuthenticationUrl { get; set; }

        public bool UsePithos { get; set; }

        public void Authenticate(string userName, string apiKey)
        {
            Contract.Requires<ArgumentNullException>(!String.IsNullOrWhiteSpace(apiKey), "ApiKey must be filled before calling Authenticate");
            Contract.Requires<ArgumentNullException>(!String.IsNullOrWhiteSpace(userName), "UserName must be filled before calling Authenticate");


            Contract.Ensures(apiKey==ApiKey);
            Contract.Ensures(userName==UserName);
            Contract.Ensures(StorageUrl!=null);
            Contract.Ensures(!String.IsNullOrWhiteSpace(Token));
            
        }

        public IList<ContainerInfo> ListContainers()
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);            

            return default(IList<ContainerInfo>);
        }

        public IList<ObjectInfo> ListObjects(string container, DateTime? since = null)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl != null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));

            return default(IList<ObjectInfo>);
        }

        public IList<ObjectInfo> ListObjects(string container, string folder, DateTime? since = null)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl != null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));
            Contract.Requires(!String.IsNullOrWhiteSpace(folder));

            return default(IList<ObjectInfo>);
        }

        public bool ContainerExists(string container)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));

            return default(bool);
        }

        public ContainerInfo GetContainerInfo(string container)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));

            return default(ContainerInfo);
        }

        public void CreateContainer(string container)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));
        }

        public void DeleteContainer(string container)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));
        }

        public Task GetObject(string container, string objectName, string fileName)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));
            Contract.Requires(!String.IsNullOrWhiteSpace(objectName));

            return default(Task);
        }

        public Task PutObject(string container, string objectName, string fileName, string hash = null)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));
            Contract.Requires(!String.IsNullOrWhiteSpace(fileName));                        
            Contract.Requires(!String.IsNullOrWhiteSpace(objectName));

            return default(Task);
        }

        public void DeleteObject(string container, string objectName)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));
            Contract.Requires(!String.IsNullOrWhiteSpace(objectName));
        }

        public void MoveObject(string sourceContainer, string oldObjectName, string targetContainer,string newObjectName)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(sourceContainer));
            Contract.Requires(!String.IsNullOrWhiteSpace(oldObjectName));
            Contract.Requires(!String.IsNullOrWhiteSpace(targetContainer));
            Contract.Requires(!String.IsNullOrWhiteSpace(newObjectName));
        }

        public bool ObjectExists(string container,string objectName)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));
            Contract.Requires(!String.IsNullOrWhiteSpace(objectName));

            return default(bool);
        }

        public ObjectInfo GetObjectInfo(string container,string objectName)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl!=null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));
            Contract.Requires(!String.IsNullOrWhiteSpace(objectName));

            return default(ObjectInfo);
        }

        public void CreateFolder(string container, string folder)
        {
            Contract.Requires(!String.IsNullOrWhiteSpace(Token));
            Contract.Requires(StorageUrl != null);
            Contract.Requires(!String.IsNullOrWhiteSpace(container));
            Contract.Requires(!String.IsNullOrWhiteSpace(folder));            
        }
    }

    public class ContainerInfo
    {
        public string Name { get; set; }
        public long Count { get; set; }
        public long Bytes { get; set; }

        public static ContainerInfo Empty=new ContainerInfo();
    }
}