using Raven.Client.Documents.Session;
using System.Collections.Generic;
using zero.Core.Options;

namespace zero.Core.Database
{
  public class ZeroStore : IZeroStore
  {
    public ZeroStore(IZeroDocumentStore raven, IZeroOptions options) : base()
    {
      Options = options;
      Raven = raven;
      //Database = null;
    }

    protected IZeroOptions Options { get; set; }
    protected Dictionary<string, IZeroDocumentSession> ScopedSessions { get; set; } = new();

    /// <inheritdoc />
    public string ResolvedDatabase { get; set; }


    /// <inheritdoc />
    public IZeroDocumentStore Raven { get; private set; }


    /// <inheritdoc />
    public IZeroDocumentSession Session(string database = null, ZeroSessionResolution resolution = ZeroSessionResolution.Reuse, SessionOptions options = null)
    {
      database ??= ResolvedDatabase;
      options ??= new SessionOptions() { Database = database };

      if (resolution == ZeroSessionResolution.Create)
      {
        return Raven.OpenAsyncSession(options) as IZeroDocumentSession;
      }

      if (!ScopedSessions.TryGetValue(database, out IZeroDocumentSession session))
      {
        session = Raven.OpenAsyncSession(options) as IZeroDocumentSession;
        ScopedSessions.TryAdd(database, session);
      }
      
      if (session.IsDisposed)
      {
        session = Raven.OpenAsyncSession(options) as IZeroDocumentSession;
        ScopedSessions.Remove(database);
        ScopedSessions.TryAdd(database, session);
      }

      return session;
    }


    /// <inheritdoc />
    public IZeroDocumentSession Session(bool global, string database = null, ZeroSessionResolution resolution = ZeroSessionResolution.Reuse, SessionOptions options = null)
    {
      return Session(global ? Options.Raven.Database : database, resolution, options);
    }
  }


  public enum ZeroSessionResolution
  {
    Reuse = 0,
    Create = 1
  }


  public interface IZeroStore
  {
    /// <summary>
    /// The database which has been resolved from the current application
    /// </summary>
    string ResolvedDatabase { get; set; }

    /// <summary>
    /// Get underlying raven document store
    /// </summary>
    IZeroDocumentStore Raven { get; }

    /// <summary>
    /// Use a specific session
    /// </summary>
    IZeroDocumentSession Session(string database = null, ZeroSessionResolution resolution = ZeroSessionResolution.Reuse, SessionOptions options = null);

    /// <summary>
    /// Use a session for the core database
    /// </summary>
    IZeroDocumentSession Session(bool global, string database = null, ZeroSessionResolution resolution = ZeroSessionResolution.Reuse, SessionOptions options = null);
  }
}