using System;
using System.Collections.Generic;
using Crestron.SimplSharp.CrestronAuthentication;
using Crestron.SimplSharp.WebScripting;
using Newtonsoft.Json;
using PepperDash.Core.Web.RequestHandlers;

namespace PepperDash.Essentials.Core.Web.RequestHandlers
{
    /// <summary>
    /// Represents a LoginRequestHandler
    /// </summary>
    public class LoginRequestHandler : WebApiBaseRequestHandler
    {
        /// <summary>
        /// Constructor
        /// </summary>
        /// <remarks>
        /// base(true) enables CORS support by default
        /// </remarks>
        public LoginRequestHandler()
            : base(true)
        {
        }

        /// <summary>
        /// Handles POST method requests for user login and token generation
        /// </summary>
        /// <param name="context">The HTTP context for the request.</param>
        protected override void HandlePost(HttpCwsContext context)
        {
            try
            {
                if (context.Request.ContentLength < 0)
                {
                    context.Response.StatusCode = 400;
                    context.Response.StatusDescription = "Bad Request";
                    context.Response.End();

                    return;
                }

                var data = context.Request.GetRequestBody();
                if (string.IsNullOrEmpty(data))
                {
                    context.Response.StatusCode = 400;
                    context.Response.StatusDescription = "Bad Request";
                    context.Response.End();

                    return;
                }

                var loginRequest = JsonConvert.DeserializeObject<LoginRequest>(data);

                if (loginRequest == null || string.IsNullOrEmpty(loginRequest.Username) || string.IsNullOrEmpty(loginRequest.Password))
                {
                    context.Response.StatusCode = 400;
                    context.Response.StatusDescription = "Bad Request";
                    context.Response.End();

                    return;
                }

                Authentication.UserToken token;

                try
                {
                    token = Authentication.GetAuthenticationToken(loginRequest.Username, loginRequest.Password);
                }
                catch (ArgumentException)
                {
                    context.Response.StatusCode = 401;
                    context.Response.StatusDescription = "Bad Request";
                    context.Response.ContentType = "application/json";
                    context.Response.ContentEncoding = System.Text.Encoding.UTF8;
                    context.Response.Write(JsonConvert.SerializeObject(new { Error = "Unauthorized" }, Formatting.Indented), false);
                    context.Response.End();
                    return;
                }

                if (!token.Valid)
                {
                    context.Response.StatusCode = 401;
                    context.Response.StatusDescription = "Unauthorized";
                    context.Response.End();

                    return;
                }

                context.Response.StatusCode = 200;
                context.Response.StatusDescription = "OK";
                context.Response.ContentType = "application/json";
                context.Response.ContentEncoding = System.Text.Encoding.UTF8;
                context.Response.Write(JsonConvert.SerializeObject(
                     new
                     {
                         Token = new LoginResponse
                         {
                             UserName = token.UserName,
                             Access = token.Access,
                             State = token.State,
                             Groups = token.Groups,
                             ADConnect = token.ADConnect,
                             Valid = token.Valid
                         }
                     }, Formatting.Indented), false);
                context.Response.End();
            }
            catch (System.Exception ex)
            {
                context.Response.StatusCode = 500;
                context.Response.StatusDescription = "Internal Server Error";
                context.Response.ContentType = "application/json";
                context.Response.ContentEncoding = System.Text.Encoding.UTF8;
                context.Response.Write(JsonConvert.SerializeObject(new { Error = ex.Message }, Formatting.Indented), false);
                context.Response.End();
            }
        }
    }

    /// <summary>
    /// Represents a LoginRequest
    /// </summary>
    public class LoginRequest
    {
        /// <summary>
        /// Gets or sets the username.
        /// </summary>
        public string Username { get; set; }

        /// <summary>
        /// Gets or sets the password.
        /// </summary>
        public string Password { get; set; }
    }

    /// <summary>
    /// Represents a LoginResponse
    /// </summary>
    internal class LoginResponse
    {
        /// <summary>
        /// Gets or sets the username.
        /// </summary>
        public string UserName { get; set; }

        /// <summary>
        /// Gets or sets the access level.
        /// </summary>
        public Authentication.UserAuthenticationLevelEnum Access { get; set; }

        /// <summary>
        /// Gets or sets the token authenticated state.
        /// </summary>
        public Authentication.eTokenAuthenticatedState State { get; set; }

        /// <summary>
        /// Gets or sets the list of groups.
        /// </summary>
        public List<string> Groups { get; set; }

        /// <summary>
        /// Gets or sets the active directory connection flag.
        /// </summary>
        public int ADConnect { get; set; }

        /// <summary>
        /// Gets or sets the valid flag indicating whether the token is valid.
        /// </summary>
        public bool Valid { get; set; }
    }
}