using System;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Web;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.RazorPages;
using trainav.web.database;

namespace trainav.web.Pages {
	public class LoginModel : PageModel {
		public void OnPost() {
			if (!Request.HasFormContentType || string.IsNullOrWhiteSpace(Request.Form["user"]) || string.IsNullOrWhiteSpace(Request.Form["pass"]))
				return;

			using var db = new Database.DbConn();
			var user = db.Users.FirstOrDefault(p => p.Username == Request.Form["user"].ToString() && p.Password == Request.Form["pass"].ToString().Sha256());
			if (user == null)
				return;

			var uid = user.UserId;
			HttpContext.Session.SetString("uid", uid.ToString());
			HttpContext.Session.SetString("authorized", "true");

			//TODO
		}
	}

	public static class StringExtensions {
		public static string Sha256(this string rawData) {
			// Create a SHA256   
			using var sha256Hash = SHA256.Create();

			// ComputeHash - returns byte array  
			var bytes = sha256Hash.ComputeHash(Encoding.UTF8.GetBytes(rawData));

			// Convert byte array to a string   
			var builder = new StringBuilder();
			for (var i = 0; i < bytes.Length; i++)
				builder.Append(bytes[i].ToString("x2"));

			return builder.ToString();
		}

		public static string Base64Encode(this string plainText) {
			var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
			return Convert.ToBase64String(plainTextBytes);
		}

		public static string UrlEncode(this string plainText)      => HttpUtility.UrlEncode(plainText);
		public static string Delimit(this   string input, int max) => input.PadRight(max, ' ').Substring(0, max).TrimEnd();
	}
}