using System;
using System.Collections.Generic;
using System.Linq;

namespace Swan.Validators {
  /// <summary>
  /// Defines a validation result containing all validation errors and their properties.
  /// </summary>
  public class ObjectValidationResult {
    private readonly List<ValidationError> _errors = new List<ValidationError>();

    /// <summary>
    /// A list of errors.
    /// </summary>
    public IReadOnlyList<ValidationError> Errors => this._errors;

    /// <summary>
    /// <c>true</c> if there are no errors; otherwise, <c>false</c>.
    /// </summary>
    public Boolean IsValid => !this.Errors.Any();

    /// <summary>
    /// Adds an error with a specified property name.
    /// </summary>
    /// <param name="propertyName">The property name.</param>
    /// <param name="errorMessage">The error message.</param>
    public void Add(String propertyName, String errorMessage) => this._errors.Add(new ValidationError { ErrorMessage = errorMessage, PropertyName = propertyName });

    /// <summary>
    /// Defines a validation error.
    /// </summary>
    public class ValidationError {
      /// <summary>
      /// The property name.
      /// </summary>
      public String PropertyName {
        get; internal set;
      }

      /// <summary>
      /// The message error.
      /// </summary>
      public String ErrorMessage {
        get; internal set;
      }
    }
  }
}