using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using System.Security.Claims;
using System.Threading.Tasks;
using zero.Core.Api;
using zero.Core.Entities;
using zero.Core.Identity;
using zero.Core.Options;
using zero.Core.Routing;

namespace zero.Core
{
  public class ZeroContext : IZeroContext
  {
    /// <inheritdoc />
    public IApplication App { get; protected set; }

    /// <inheritdoc />
    public string AppId { get; protected set; }

    /// <inheritdoc />
    public ClaimsPrincipal BackofficeUser { get; protected set; }

    /// <inheritdoc />
    public ClaimsIdentity BackofficeIdentity { get; protected set; }

    /// <inheritdoc />
    public bool IsBackofficeRequest { get; protected set; }

    /// <inheritdoc />
    public IZeroOptions Options { get; protected set; }

    /// <inheritdoc />
    public IRoute Route { get; private set; }

    /// <inheritdoc />
    public IResolvedRoute ResolvedRoute { get; private set; }


    protected IApplicationContext AppContext { get; private set; }

    protected ILogger<ZeroContext> Logger { get; private set; }


    private bool _resolved = false;


    public ZeroContext(IZeroOptions options, IApplicationContext appContext, ILogger<ZeroContext> logger)
    {
      Options = options;
      AppContext = appContext;
      Logger = logger;
    }


    /// <inheritdoc />
    public async virtual Task Resolve(HttpContext context)
    {
      if (_resolved || context?.Request is null)
      {
        return;
      }

      _resolved = true;

      AuthenticateResult authResult = await context.AuthenticateAsync(Constants.Auth.BackofficeScheme);
      if (authResult?.Principal is not null)
      {
        BackofficeUser = authResult.Principal;
        if (BackofficeUserIdentity.TryGet(authResult.Principal, out BackofficeUserIdentity identity))
        {
          BackofficeIdentity = identity;
        }
      }
      else
      {
        BackofficeUser = new ClaimsPrincipal();
      }

      App = await AppContext.Resolve(context, BackofficeUser);
      AppId = App.Id;

      IsBackofficeRequest = AppContext.IsBackofficeRequest(context);

      if (IsBackofficeRequest is false && context.Request.RouteValues.TryGetValue("zero.route", out object route))
      {
        ResolvedRoute = (IResolvedRoute)route;
        Route = ResolvedRoute.Route;
      }
    }
  }


  public interface IZeroContext
  {
    /// <summary>
    /// Currently loaded application
    /// </summary>
    IApplication App { get; }

    /// <summary>
    /// Current loaded application Id
    /// </summary>
    string AppId { get; }

    /// <summary>
    /// Resolved backoffice user principal
    /// </summary>
    ClaimsPrincipal BackofficeUser { get; }

    /// <summary>
    /// Resolved backoffice user identity
    /// </summary>
    ClaimsIdentity BackofficeIdentity { get; }

    /// <summary>
    /// Whether the current request is a backoffice request or not
    /// </summary>
    bool IsBackofficeRequest { get; }

    /// <summary>
    /// Global zero options
    /// </summary>
    IZeroOptions Options { get; }

    /// <summary>
    /// Matching (frontend) path route
    /// </summary>
    IRoute Route { get; }

    /// <summary>
    /// Matching (frontend) resolved route
    /// </summary>
    IResolvedRoute ResolvedRoute { get; }

    /// <summary>
    /// Resolves the current application (for backoffice + frontend requests) and
    /// the currently active backoffice user, as users are not signed in with the default scheme and do therefore not populate HttpContext.User
    /// </summary>
    Task Resolve(HttpContext context);
  }
}