using System.Diagnostics;
using System.Security.Claims;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using bitforum.Models;
using bitforum.Models.Views;
using bitforum.Constants;

namespace bitforum.Controllers.Director
{
    [Authorize]
    [Route("Director")]
    public class RoleController : Controller
    {
        private readonly ILogger<RoleController> _logger;
        private readonly string _RoleViewPath = "~/Views/Director/Role.cshtml";
        private readonly string _PermissionViewPath = "~/Views/Director/Permission.cshtml";
        private readonly RoleManager<IdentityRole> _roleManager;

        public RoleController(ILogger<RoleController> logger, RoleManager<IdentityRole> roleManager)
        {
            _logger = logger;
            _roleManager = roleManager;
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }

        [HttpGet("Role")]
        public async Task<IActionResult> Index()
        {
            var roles = await _roleManager.Roles.ToListAsync();
            var roleClaimsCount = new Dictionary<string, int>();

            if (roles.Count > 0)
            {
                foreach (var role in roles)
                {
                    var claims = await _roleManager.GetClaimsAsync(role);
                    roleClaimsCount[role.Name] = claims.Count;
                }
            }

            ViewBag.RoleClaimsCount = roleClaimsCount;

            return View(_RoleViewPath, roles);
        }

        [HttpPost("Role")]
        public async Task<IActionResult> Add([FromForm(Name = "role_name")] string name)
        {
            try {

                // 수동 유효성 검사
                if (string.IsNullOrWhiteSpace(name))
                {
                    ModelState.AddModelError("Role:", "역할 이름은 필수입니다.");
                }
                else if (name.Length > 256)
                {
                    ModelState.AddModelError("Role:", "역할 이름은 256자를 초과할 수 없습니다.");
                }

                if (!ModelState.IsValid)
                {
                    throw new Exception("역할 추가에 실패하였습니다.");
                }

                if (await _roleManager.RoleExistsAsync(name))
                {
                    ModelState.AddModelError("Role:", $"{name} 은 이미 존재합니다.");
                    throw new Exception("역할 중복 오류");
                }
            }
            catch (Exception e)
            {
                var roles = await _roleManager.Roles.ToListAsync();
                _logger.LogError(e, e.Message);
                TempData["ErrorMessages"] = "역할 추가가 정상적으로 완료되었습니다.";

                return View(_RoleViewPath, roles);
            }

            await _roleManager.CreateAsync(new IdentityRole(name.Trim()));

            var message = $"{name}이 정상적으로 추가되었습니다.";
            TempData["SuccessMessage"] = message;
            _logger.LogInformation(message);
            return RedirectToAction("index", "Role");
        }

        [HttpGet("ManagePermissions")]
        public async Task<IActionResult> ManagePermissions(string roleID)
        {
            var role = await _roleManager.FindByIdAsync(roleID);

            if (role == null)
            {
                return NotFound();
            }

            // 역할에 따른 권한들 조회
            var roleClaims = _roleManager.GetClaimsAsync(role).Result.Select(c => c.Value).ToList();

            // 권한 생성
            var allClaims = Permissions.GeneratePermissions();

            // 모든 권한 목록 생성
            var allPermissions = allClaims.Select(p => new CheckBoxViewModel { DisplayValue = p, IsSelected = roleClaims.Contains(p) }).ToList();

            var viewModel = new PermissionsFormViewModel
            {
                RoleID = roleID,
                RoleName = role.Name,
                RoleClaims = allPermissions
            };

            return View(_PermissionViewPath, viewModel);
        }

        [HttpPost("ManagePermissions")]
        public async Task<IActionResult> ManagePermissions(PermissionsFormViewModel request)
        {
            var role = await _roleManager.FindByIdAsync(request.RoleID);

            if (role == null)
            {
                return NotFound();
            }

            var roleClaims = await _roleManager.GetClaimsAsync(role);

            foreach (var claim in roleClaims)
            {
                await _roleManager.RemoveClaimAsync(role, claim);
            }

            var selectedClaims = request.RoleClaims.Where(c => c.IsSelected).ToList();

            foreach (var claim in selectedClaims)
            {
                await _roleManager.AddClaimAsync(role, new Claim("Permission", claim.DisplayValue));
            }

            var message = "권한이 정상적으로 적용되었습니다.";
            TempData["SuccessMessage"] = message;
            _logger.LogInformation(message);

            return RedirectToAction("ManagePermissions", "Role", new { request.RoleID });
        }
    }
}