using System;
using System.Collections.Generic;

namespace Salesforce.NET
{
    public sealed class Result<T> : Result
    {
        public T Data { get; set; }

        /// <summary>
        /// Creates a new failed result (<see cref="Success" /> is false)
        /// </summary>
        public Result() { }

        /// <summary>
        /// Creates a new result
        /// </summary>
        /// <param name="success"></param>
        public Result(bool success) : base(success) { }

        /// <summary>
        /// Creates a new failed result with error message
        /// </summary>
        /// <param name="error"></param>
        public Result(string error) : base(error) { }
    }

    public class Result
    {
        public bool Success { get; set; }
        public string Message { get; set; }

        /// <summary>
        /// Collection of errors that have occurred during the request
        /// </summary>
        public ICollection<string> Errors { get; set; } = new List<string>();

        #region Constructor

        /// <summary>
        /// Creates a new failed result (<see cref="Success" /> is false)
        /// </summary>
        public Result() { }

        /// <summary>
        /// Creates a new result
        /// </summary>
        /// <param name="success"></param>
        public Result(bool success) => Success = success;

        /// <summary>
        /// Creates a new failed result with error message
        /// </summary>
        /// <param name="error"></param>
        public Result(string error) => AddError(error);

        #endregion

        /// <summary>
        /// Adds an error to the collection and sets <see cref="Success"/> to false
        /// </summary>
        /// <param name="error"></param>
        public void AddError(string error)
        {
            // force to false if previously true
            Success = false;

            AddDistinctError(error);
        }

        /// <summary>
        /// Adds an error to the collection and sets <see cref="Success"/> to false
        /// </summary>
        /// <param name="ex"></param>
        public void AddError(Exception ex)
        {
            // force to false if previously true
            Success = false;

            if (ex == null)
            {
                return;
            }

            AddDistinctError(ex.Message);
        }

        /// <summary>
        /// Adds a list of errors to the collection and sets <see cref="Success"/> to false
        /// </summary>
        /// <param name="errors"></param>
        public void AddErrors(IEnumerable<string> errors)
        {
            // force to false if previously true
            Success = false;

            if (errors == null)
            {
                return;
            }

            foreach (var error in errors)
            {
                AddDistinctError(error);
            }
        }

        #region Private Methods

        /// <summary>
        /// Adds only a distinct error string to the list
        /// </summary>
        /// <param name="error"></param>
        private void AddDistinctError(string error)
        {
            if (!string.IsNullOrWhiteSpace(error) && !Errors.Contains(error))
            {
                Errors.Add(error);
            }
        }

        #endregion
    }
}