using Microsoft.AspNetCore.Authentication.JwtBearer;
using OnlyPrompt.Backend.Database.Models;
using System.Diagnostics.CodeAnalysis;
using System.Linq.Expressions;
using System.Runtime.CompilerServices;
using System.Security.Claims;

namespace OnlyPrompt.Backend.Utils
{
	public static class Extensions
	{
		public static string? GetIdentifier(this ClaimsPrincipal principal) => principal.FindFirstValue(ClaimTypes.NameIdentifier);
		public static bool TryGetIdentifier(this ClaimsPrincipal principal, [NotNullWhen(true)]out string? identifier)
		{
			identifier = principal.FindFirstValue(ClaimTypes.NameIdentifier);
			return identifier != null;
		}

		public static Guid? GetUserId(this ClaimsPrincipal principal)
		{
			if (principal.TryGetIdentifier(out var identifier) && Guid.TryParse(identifier, out var userId))
				return userId;

			return null;
		}

		public static IEnumerable<Claim> GetClaims(this UserModel user)
		{
			yield return new Claim(ClaimTypes.NameIdentifier, user.Id.ToString());
			yield return new Claim(ClaimTypes.Name, user.UserName);
			yield return new Claim(ClaimTypes.Email, user.Email);	
			
			foreach (var role in user.Roles)
				yield return new Claim(ClaimTypes.Role, role);
		}

		public static IQueryable<T> OrderBy<T, TKey>(this IQueryable<T> source, Expression<Func<T, TKey>> selecter, bool ascending)
		{
			if(ascending)
				return source.OrderBy(selecter);
			else
				return source.OrderByDescending(selecter);
		}

		public static CookieOptions Copy(this CookieOptions options, Action<CookieOptions>? modify = null)
		{
			var newOptions = new CookieOptions
			{
				Domain = options.Domain,
				Expires = options.Expires,
				HttpOnly = options.HttpOnly,
				IsEssential = options.IsEssential,
				MaxAge = options.MaxAge,
				Path = options.Path,
				SameSite = options.SameSite,
				Secure = options.Secure
			};

			modify?.Invoke(newOptions);
			return newOptions;
		}

		public static string Limit(this string @string, int maxLength)
		{
			if (@string.Length <= maxLength)
				return @string;
			return @string.Substring(0, maxLength);
		}

		public const string LowerAlphabet = "abcdefghijklmnopqrstuvwxyz";
		public static string GetString(this Random @random, int lenght, string alphabet = LowerAlphabet)
		{
			Span<char> chars = stackalloc char[lenght];
			for (int i = 0; i < lenght; i++)
				chars[i] = alphabet[@random.Next(alphabet.Length)];

			return new string(chars);
		}
	}
}