using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Http;
using System;
using System.Web;
using SecureCore.Services;
using SecureCore.Authentication;

namespace SecureCore.Controllers
{
    [Route("[controller]")]
    [ApiController]
    public class AuthController : Controller
    {
        //TODO: Login will only ever return messages like "Wrong username / password." whereas register can return messages like "User exists.", "Password to weak", or "Password in top 100 most used.".
        [HttpPost("login")]
        [AcceptVerbs("POST")]
        public IActionResult Login([FromBody] UserInformation.LoginData info)
        {
            AppSettingsManager.TryGetConnectionStringByName("MainDataConnectionString", out string connectionString);
            //TODO: see if the request has an active session key so we don't spam out new keys like mad
            try
            {
                if (HttpContext.Request.Cookies.ContainsKey("Session"))
                    if (SessionManager.IsSessionTokenValid(HttpContext.Request.Cookies["Session"], connectionString))
                        return Ok("Logged in\n");

                //Verify that the username provided is valid, i.e. no whitespace, special characters, etc.
                var result = UserDataService.IsUsernameValid(info.Username);
                //If the name isn't valid, return the error message to the user.
                if (!result.IsValid) return Unauthorized(result.Message);

                //Next try to get the user's login data, if the fuction returns empty strings, then the user isn't a registered name.
                var (password, salt) = PasswordManager.GetPasswordHashAndSalt(info.Username, connectionString);
                //If the user name isn't in the system, then simply return a generic error message about something not being right.
                if (password == string.Empty) return Unauthorized("User name or password is not correct.");

                result = PasswordManager.IsPasswordValid(info.Password);

                if (!result.IsValid) return Unauthorized(result.Message);

                if(!PasswordManager.IsPasswordAMatch(info.Password, salt, password)) return Unauthorized("User name or password is not correct.");

                var sessionToken = SessionManager.CreateSessionToken();
                var agent = HttpContext.Request.Headers[Microsoft.Net.Http.Headers.HeaderNames.UserAgent];
                var ip = PasswordManager.HashStringData(Request.HttpContext.Connection.RemoteIpAddress.MapToIPv4().ToString(), salt);
                var cookieOptions = GetCookieOptions();

                SessionManager.Login(info.Username, sessionToken, cookieOptions.Expires.Value.UtcDateTime, agent, ip, connectionString);

                HttpContext.Response.Cookies.Append("Session", sessionToken, cookieOptions);

                return Ok($"Logged in success{Environment.NewLine}");
            }
            catch(Exception ex)
            {
                //TODO: Log this event.
                return Unauthorized("An error has occured trying to process your request, please try again in a few minutes.");
            }
        }

        [HttpPost("Register")]
        [AcceptVerbs("POST")]
        public IActionResult Register([FromBody] UserInformation.RegistrationData info)
        {
            //Verify that the username provided is valid, i.e. no whitespace, special characters, etc.
            var result = UserDataService.IsUsernameValid(info.Username);
            //If the name isn't valid, return the error message to the user.
            if (!result.IsValid) return Unauthorized(result.Message);
            //Validate the password, make sure its not to long or short, etc.
            result = PasswordManager.IsPasswordValid(info.Password);

            if (!result.IsValid) return Unauthorized(result.Message);

            AppSettingsManager.TryGetConnectionStringByName("MainDataConnectionString", out string connectionString);
            var (hash, salt) =  PasswordManager.HashPassword(info.Password);
            var sessionToken = SessionManager.CreateSessionToken();
            var agent = HttpContext.Request.Headers[Microsoft.Net.Http.Headers.HeaderNames.UserAgent];
            var ip = PasswordManager.HashStringData(Request.HttpContext.Connection.RemoteIpAddress.MapToIPv4().ToString(), salt);

            try
            {
                var cookieOptions = GetCookieOptions();

                var i = UserDataService.RegisterNewUser(info.Username, info.Email, hash, salt, sessionToken, cookieOptions.Expires.Value.UtcDateTime, agent, ip, connectionString);

                HttpContext.Response.Cookies.Append("Session", sessionToken, cookieOptions);

                return Ok($"New User ID: {i}");
            }
            catch (Exception e)
            {
                return Unauthorized(e.Message);
            }
        }

        [HttpPost("Logout")]
        [AcceptVerbs("POST")]
        public IActionResult Logout()
        {
            AppSettingsManager.TryGetConnectionStringByName("MainDataConnectionString", out string connectionString);

            SessionManager.Logout(HttpContext.Request.Cookies["Session"], connectionString);

            HttpContext.Response.Cookies.Delete("Session");

            return Ok();
        }

        [HttpPost("ResetPassword")]
        [AcceptVerbs("POST")]
        public IActionResult ResetPassword([FromQuery] string token, [FromBody] string password)
        {
            AppSettingsManager.TryGetConnectionStringByName("MainDataConnectionString", out string connectionString);

            try
            {
                if (!SessionManager.IsSessionTokenValid(token, connectionString, true)) return Unauthorized("Token invalid");

                var (Hash, Salt) = PasswordManager.HashPassword(password);

                PasswordManager.ResetPassword(Hash, Salt, token, connectionString);

                return Ok("Reset successful\n");
            }
            catch (Exception e)
            {
                return Unauthorized(e.Message);
            }
        }

        [HttpPost("CreatePasswordResetLink")]
        [AcceptVerbs("POST")]
        public IActionResult CreatePasswordResetLink([FromBody] string email)
        {
            AppSettingsManager.TryGetConnectionStringByName("MainDataConnectionString", out string connectionString);
            var token = SessionManager.CreateSessionToken();
            var agent = HttpContext.Request.Headers[Microsoft.Net.Http.Headers.HeaderNames.UserAgent];
            var ip = PasswordManager.HashStringData(Request.HttpContext.Connection.RemoteIpAddress.MapToIPv4().ToString());

            try
            {
                PasswordManager.InsertPasswordResetRequest(email, token, DateTime.Now.AddHours(1), agent, ip, connectionString);

                token = HttpUtility.UrlEncode(token);

                return Ok($"192.168.255.200:5000/auth/ResetPassword?token={token}{Environment.NewLine}");
            }
            catch(Exception e)
            {
                return Unauthorized($"{e.Message}{Environment.NewLine}");
            }
        }

        private CookieOptions GetCookieOptions()
        {
            return new CookieOptions
            {
                //Domain = "copyrightcrusader.org",
                Expires = DateTime.Now.AddDays(7),
                //HttpOnly = true,
                //Secure = true,
                Path = "/",
                SameSite = SameSiteMode.Strict
            };
        }
    }

    //TODO: Read more https://www.valentinog.com/blog/cookies/
    // And this https://blog.webf.zone/ultimate-guide-to-http-cookies-2aa3e083dbae
}