social-media/src/Infrastructure/Identity/IdentityService.cs

using Google.Apis.Oauth2.v2.Data;
using System.Security.Claims;
using Hutopy.Application.Common.Interfaces;
using Hutopy.Application.Common.Models;
using Hutopy.Infrastructure.Utils;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.Options;

namespace Hutopy.Infrastructure.Identity;

public class IdentityService(
    ApplicationUserManager userManager,
    SignInManager<ApplicationUser> signInManager,
    IUserClaimsPrincipalFactory<ApplicationUser> userClaimsPrincipalFactory,
    IAuthorizationService authorizationService,
    IHttpContextAccessor contextAccessor,
    IOptionsSnapshot<JwtOptions> jwtOptions
)
    : IIdentityService
{
    public async Task<string?> GetUserNameAsync(Guid userId)
    {
        var user = await userManager.FindByIdAsync(userId.ToString());

        return user?.UserName;
    }

    public async Task<UserModel?> GetUserByUserNameAsync(string userName)
    {
        var user = await userManager.FindByNameAsync(userName);

        if (user == null) return null;

        return new()
        {
            Id = user.Id,
            Username = user.UserName!,
            PhoneNumber = user.PhoneNumber,
            Email = user.Email,
            Alias = user.Alias,
            Firstname = user.Firstname,
            Lastname = user.Lastname,
            BirthDate = user.BirthDate,
            Address = user.Address,
            PortraitUrl = user.PortraitUrl
        };
    }

    public async Task<Result<Guid>> CreateUserAsync(Userinfo userInfo)
    {
        var applicationUser = new ApplicationUser
        {
            UserName = userInfo.Name,
            Email = userInfo.Email,
            Firstname = userInfo.GivenName,
            Lastname = userInfo.FamilyName
        };

        var password = Guid.NewGuid().ToString("N")[..32];

        var identityResult = await userManager.CreateAsync(applicationUser, password);

        var applicationResult = identityResult.ToApplicationResult();

        var result = new Result<Guid>(applicationUser.Id, applicationResult.Succeeded, applicationResult.Errors);

        return result;
    }

    public async Task<Result<Guid>> CreateUserAsync(string email, string userName, string firstName, string lastName,
        string password)
    {
        var applicationUser = new ApplicationUser
        {
            UserName = userName, Email = email, Firstname = firstName, Lastname = lastName
        };

        var response = await userManager.CreateAsync(applicationUser, password);

        if (!response.Succeeded)
        {
            throw new BadHttpRequestException(response.Errors.First().Description);
        }

        var result = new Result<Guid>(applicationUser.Id, response.Succeeded, response.ToApplicationResult().Errors);

        return result;
    }

    public async Task<Result<Guid>> UpdateCurrentUserAsync(UserModel userModel)
    {
        var applicationUser = await userManager.FindByIdAsync(userModel.Id.ToString());

        if (applicationUser is null) return Result<Guid>.Failure(Guid.Empty, new[] { "User not found." });

        applicationUser.Id = userModel.Id;
        applicationUser.Email = userModel.Email;
        applicationUser.PhoneNumber = userModel.PhoneNumber;
        applicationUser.Alias = userModel.Alias;
        applicationUser.Firstname = userModel.Firstname;
        applicationUser.Lastname = userModel.Lastname;
        applicationUser.BirthDate = userModel.BirthDate;
        applicationUser.Address = userModel.Address;
        applicationUser.PortraitUrl = userModel.PortraitUrl;

        var response = await userManager.UpdateAsync(applicationUser);

        var applicationResult = response.ToApplicationResult();

        var result = new Result<Guid>(
            userModel.Id,
            applicationResult.Succeeded,
            applicationResult.Errors);

        return result;
    }


    private static UserModel BuildModelFrom(ApplicationUser response)
    {
        var userModel = new UserModel
        {
            Id = response.Id,
            Username = response.UserName ?? string.Empty,
            PhoneNumber = response.PhoneNumber ?? string.Empty,
            Email = response.Email ?? string.Empty,
            PortraitUrl = response.PortraitUrl,
            Alias = response.Alias,
            Firstname = response.Firstname,
            Lastname = response.Lastname,
            BirthDate = response.BirthDate,
            Address = response.Address,
        };

        return userModel;
    }

    public async Task<UserModel?> FindUserByIdAsync(string id)
    {
        var user = await userManager.FindByIdAsync(id);

        if (user == null) return null;

        var userModel = BuildModelFrom(user);

        return userModel;
    }

    public async Task<UserModel?> FindUserByEmailAsync(string email)
    {
        var response = await userManager.FindByEmailAsync(email);

        if (response == null) return null;

        return BuildModelFrom(response);
    }

    public async Task<UserModel?> GetCurrentUserAsync()
    {
        var currentUserId = contextAccessor.HttpContext?.User.FindFirst(ClaimTypes.NameIdentifier)?.Value;
        if (string.IsNullOrEmpty(currentUserId))
        {
            return null;
        }

        return await FindUserByIdAsync(currentUserId);
    }

    public async Task<Result> UpdateCurrentUserPortraitUrlAsync(string url)
    {
        var userModel = await GetCurrentUserAsync();

        var applicationUser = await userManager.FindByIdAsync(userModel.Id.ToString());
        if (applicationUser is null) return Result.Failure(["ApplicationUser not found."]);

        applicationUser.PortraitUrl = url;

        var response = await userManager.UpdateAsync(applicationUser);

        return response.ToApplicationResult();
    }

    public async Task<bool> IsInRoleAsync(Guid userId, string role)
    {
        var user = await userManager.FindByIdAsync(userId.ToString());

        return user != null && await userManager.IsInRoleAsync(user, role);
    }

    public async Task<bool> CurrentUserIsInRoleAsync(string role)
    {
        var currentUserModel = await GetCurrentUserAsync();
        var currentUser = await userManager.FindByIdAsync(currentUserModel.Id.ToString());

        return currentUser != null && await userManager.IsInRoleAsync(currentUser, role);
    }

    public async Task<bool> AuthorizeAsync(Guid userId, string policyName)
    {
        var user = await userManager.FindByIdAsync(userId.ToString());

        if (user == null)
        {
            return false;
        }

        var principal = await userClaimsPrincipalFactory.CreateAsync(user);

        var result = await authorizationService.AuthorizeAsync(principal, policyName);

        return result.Succeeded;
    }

    public async Task<Result> DeleteUserAsync(string userId)
    {
        var user = await userManager.FindByIdAsync(userId);

        return user != null ? await DeleteUserAsync(user) : Result.Success();
    }

    public async Task<Result> DeleteUserAsync(ApplicationUser user)
    {
        var result = await userManager.DeleteAsync(user);

        return result.ToApplicationResult();
    }

    public async Task<Result> AddRoleAsync(string userId, string role)
    {
        var hasAdminAccess = await CurrentUserIsInRoleAsync("Administrator");

        if (!hasAdminAccess) return Result.Failure(new[] { "Only administrator can assign new roles to a user." });

        var user = await userManager.FindByIdAsync(userId);

        if (user is null) return Result.Failure(new[] { "User not found." });

        var result = await userManager.AddToRoleAsync(user, role);

        return result.ToApplicationResult();
    }

    public async Task<IList<string>> GetCurrentUserRolesAsync()
    {
        var currentUserModel = await GetCurrentUserAsync();

        var currentUser = await userManager.FindByIdAsync(currentUserModel.Id.ToString());

        if (currentUser is null) return [];

        var userRoles = await userManager.GetRolesAsync(currentUser);

        return userRoles;
    }

    public async Task<string?> LoginAsync(string userName, string password)
    {
        var result =
            await signInManager.PasswordSignInAsync(userName, password, isPersistent: false, lockoutOnFailure: false);

        if (!result.Succeeded)
        {
            return null;
        }

        var user = await GetUserByUserNameAsync(userName);

        if (user is null) throw new InvalidOperationException();

        var token = JwtTokenHelper.GenerateJwtToken(
            expiresIn: jwtOptions.Value.Lifetime,
            issuer: jwtOptions.Value.Issuer,
            audience: jwtOptions.Value.Audience,
            key: jwtOptions.Value.Key,
            userId: user.Id.ToString(),
            email: user.Email,
            alias: user.Alias,
            firstname: user.Firstname,
            lastname: user.Lastname,
            portraitUrl: user.PortraitUrl);

        return token;
    }
}