using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.ComponentModel;
using HeuristicLab.BackgroundProcessing;
using HeuristicLab.OKB.Client;
using HeuristicLab.OKB.Cockpit.Admin.OKBData;

namespace HeuristicLab.OKB.Cockpit.Admin {
  public class DataClientHelper {

    BackgroundWorker host;
    public Action<int> ReportProgress { get; set; }
    System.ComponentModel.DoWorkEventArgs args;

    public DataClientHelper(BackgroundWorker host, DoWorkEventArgs args) {      
      this.host = host;
      this.args = args;
      if (host.WorkerReportsProgress)
        ReportProgress = i => host.ReportProgress(i);
      else
        ReportProgress = new Action<int>(i => { });
    }

    public byte[] Load(OKBData.EntityType type, int id) {
      DataServiceClient dataClient = ClientFactory.Create<DataServiceClient, IDataService>();
      int size = dataClient.Request(type, id);
      using (MemoryStream dataStream = new MemoryStream()) {
        int chunkSize = Math.Max(100, Math.Min(1024 * 1024, size / 100));
        while (!host.CancellationPending && dataStream.Position < size) {
          byte[] chunk = dataClient.GetNextChunk(chunkSize);
          dataStream.Write(chunk, 0, chunk.Length);
          ReportProgress(100 * (int)dataStream.Position / size);
        }
        if (host.CancellationPending) {
          args.Cancel = true;
          dataClient.AbortTransfer();
          dataClient.Close();
          return null;
        } else {
          dataClient.TransferDone();
          dataClient.Close();
          ReportProgress(100);
          return dataStream.ToArray();
        }        
      }
    }

    public void Save(OKBData.EntityType type, int id, byte[] data) {
      DataServiceClient dataClient = ClientFactory.Create<DataServiceClient, IDataService>();
      dataClient.Submit(type, id);
      using (MemoryStream dataStream = new MemoryStream(data)) {
        int size = Math.Max(100, Math.Min(1024 * 1024, (int)dataStream.Length / 100));
        for (int i = 0; i < dataStream.Length && !host.CancellationPending; i += size) {
          byte[] chunk = new byte[Math.Min(size, dataStream.Length - dataStream.Position)];
          dataStream.Read(chunk, 0, chunk.Length);
          dataClient.SetNextChunk(chunk);
          ReportProgress(100 * (int)dataStream.Position / (int)dataStream.Length);
        }
        if (host.CancellationPending) {
          args.Cancel = true;
          dataClient.AbortTransfer();
        } else {
          dataClient.TransferDone();
        }
        dataClient.Close();
      }
    }

  }
}