NET8

Fab2ApprovalMKLink/.vscode/mklink.md

@@ -36,14 +36,36 @@ mklink /J "L:\DevOps\Mesa_FI\MesaFabApproval\Fab2ApprovalMKLink\Jobs" "L:\DevOps
 mklink /J "L:\DevOps\Mesa_FI\MesaFabApproval\Fab2ApprovalMKLink\JobSchedules" "L:\DevOps\Mesa_FI\MesaFabApproval\Fab2ApprovalSystem\JobSchedules"
 ```
 
-```bash 1734015544321 = 638696123443210000 = Thu Dec 12 2024 07:59:03 GMT-0700 (Mountain Standard Time)
-mklink /J ".vscode\.UserSecrets" "%AppData%\Microsoft\UserSecrets\f2da5035-aba9-4676-9f8d-d6689f84663d"
-mklink /J "DMO" "..\Fab2ApprovalSystem\DMO"
-mklink /J "Jobs" "..\Fab2ApprovalSystem\Jobs"
-mklink /J "JobSchedules" "..\Fab2ApprovalSystem\JobSchedules"
-mklink /J "Misc" "..\Fab2ApprovalSystem\Misc"
-mklink /J "Models" "..\Fab2ApprovalSystem\Models"
-mklink /J "PdfGenerator" "..\Fab2ApprovalSystem\PdfGenerator"
-mklink /J "Utilities" "..\Fab2ApprovalSystem\Utilities"
-mklink /J "ViewModels" "..\Fab2ApprovalSystem\ViewModels"
+```bash 1747242128286 = 638828389282860000 = 2025-2.Spring = Wed May 14 2025 10:02:07 GMT-0700 (Mountain Standard Time)
+mklink /J "Fab2ApprovalMKLink\.vscode\.UserSecrets" "%AppData%\Microsoft\UserSecrets\f2da5035-aba9-4676-9f8d-d6689f84663d"
+mklink /J "Fab2ApprovalMKLink\Controllers" "Fab2ApprovalSystem\Controllers"
+mklink /J "Fab2ApprovalMKLink\DMO" "Fab2ApprovalSystem\DMO"
+mklink /J "Fab2ApprovalMKLink\Jobs" "Fab2ApprovalSystem\Jobs"
+mklink /J "Fab2ApprovalMKLink\JobSchedules" "Fab2ApprovalSystem\JobSchedules"
+mklink /J "Fab2ApprovalMKLink\Misc" "Fab2ApprovalSystem\Misc"
+mklink /J "Fab2ApprovalMKLink\Models" "Fab2ApprovalSystem\Models"
+mklink /J "Fab2ApprovalMKLink\PdfGenerator" "Fab2ApprovalSystem\PdfGenerator"
+mklink /J "Fab2ApprovalMKLink\Utilities" "Fab2ApprovalSystem\Utilities"
+mklink /J "Fab2ApprovalMKLink\ViewModels" "Fab2ApprovalSystem\ViewModels"
+mklink /J "Fab2ApprovalMKLink\ViewModels" "Fab2ApprovalSystem\ViewModels"
+```
+
+```bash 1747249935803 = 638828467358030000 = 2025-2.Spring = Wed May 14 2025 12:12:15 GMT-0700 (Mountain Standard Time)
+mkdir "Fab2ApprovalMKLink\Views"
+mklink /J "Fab2ApprovalMKLink\Views\Account" "Fab2ApprovalSystem\Views\Account"
+mklink /J "Fab2ApprovalMKLink\Views\Admin" "Fab2ApprovalSystem\Views\Admin"
+mklink /J "Fab2ApprovalMKLink\Views\Audit" "Fab2ApprovalSystem\Views\Audit"
+mklink /J "Fab2ApprovalMKLink\Views\ChangeControl" "Fab2ApprovalSystem\Views\ChangeControl"
+mklink /J "Fab2ApprovalMKLink\Views\CorrectiveAction" "Fab2ApprovalSystem\Views\CorrectiveAction"
+mklink /J "Fab2ApprovalMKLink\Views\ECN" "Fab2ApprovalSystem\Views\ECN"
+mklink /J "Fab2ApprovalMKLink\Views\Home" "Fab2ApprovalSystem\Views\Home"
+mklink /J "Fab2ApprovalMKLink\Views\LotDisposition" "Fab2ApprovalSystem\Views\LotDisposition"
+mklink /J "Fab2ApprovalMKLink\Views\LotTraveler" "Fab2ApprovalSystem\Views\LotTraveler"
+mklink /J "Fab2ApprovalMKLink\Views\Manager" "Fab2ApprovalSystem\Views\Manager"
+mklink /J "Fab2ApprovalMKLink\Views\MRB" "Fab2ApprovalSystem\Views\MRB"
+mklink /J "Fab2ApprovalMKLink\Views\PartsRequest" "Fab2ApprovalSystem\Views\PartsRequest"
+mklink /J "Fab2ApprovalMKLink\Views\Reports" "Fab2ApprovalSystem\Views\Reports"
+mklink /J "Fab2ApprovalMKLink\Views\Shared" "Fab2ApprovalSystem\Views\Shared"
+mklink /J "Fab2ApprovalMKLink\Views\Training" "Fab2ApprovalSystem\Views\Training"
+mklink /J "Fab2ApprovalMKLink\Views\Workflow" "Fab2ApprovalSystem\Views\Workflow"
 ```

Fab2ApprovalMKLink/Fab2ApprovalMKLink.csproj

@@ -30,6 +30,7 @@
     <PackageReference Include="EntityFramework" Version="6.5.1" />
     <PackageReference Include="ExcelDataReader" Version="3.7.0" />
     <PackageReference Include="jQuery" Version="3.7.1" />
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="8.0.8" />
     <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.Server" Version="8.0.10" />
     <PackageReference Include="Microsoft.Data.SqlClient" Version="5.2.0" />
     <PackageReference Include="Microsoft.Data.Sqlite" Version="8.0.2" />

Fab2ApprovalMKLink/Program.cs

@@ -1,15 +1,23 @@
 using System;
 using System.Diagnostics;
+using System.Text;
 
+using Fab2ApprovalSystem.Misc;
 using Fab2ApprovalSystem.Models;
+using Fab2ApprovalSystem.Services;
 
+using Microsoft.AspNetCore.Authentication.JwtBearer;
+using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.ViewEngines;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Hosting.WindowsServices;
 using Microsoft.Extensions.Logging;
+using Microsoft.IdentityModel.Tokens;
 
 namespace Fab2ApprovalMKLink;
 
@@ -24,12 +32,36 @@ public class Program {
             throw new Exception("Company name must have a value!");
         if (string.IsNullOrEmpty(appSettings.WorkingDirectoryName))
             throw new Exception("Working directory name must have a value!");
+        GlobalVars.AppSettings = appSettings;
+        GlobalVars.AttachmentUrl = appSettings.AttachmentUrl is null ? string.Empty : appSettings.AttachmentUrl;
+        GlobalVars.CA_BlankFormsLocation = appSettings.CABlankFormsLocation;
+        GlobalVars.DBConnection = appSettings.DBConnection;
+        GlobalVars.DB_CONNECTION_STRING = appSettings.DBConnectionString;
+        GlobalVars.hostURL = appSettings.HostURL;
+        GlobalVars.IS_INFINEON_DOMAIN = appSettings.IsInfineonDomain;
+        GlobalVars.MesaTemplateFiles = appSettings.MesaTemplateFiles;
+        GlobalVars.NDriveURL = appSettings.NDriveURL;
+        GlobalVars.SENDER_EMAIL = appSettings.SenderEmail;
+        GlobalVars.USER_ID = appSettings.UserId;
+        GlobalVars.USER_ISADMIN = appSettings.UserIsAdmin;
+        GlobalVars.WSR_URL = appSettings.WSR_URL;
         try {
             _ = webApplicationBuilder.Services.Configure<ApiBehaviorOptions>(options => options.SuppressModelStateInvalidFilter = true);
             _ = webApplicationBuilder.Services.AddControllers();
+            _ = webApplicationBuilder.Services.AddControllersWithViews();
             _ = webApplicationBuilder.Services.AddDistributedMemoryCache();
             _ = webApplicationBuilder.Services.AddHttpClient();
+            _ = webApplicationBuilder.Services.AddMemoryCache();
             _ = webApplicationBuilder.Services.AddSingleton(_ => appSettings);
+            _ = webApplicationBuilder.Services.AddSingleton<ICompositeViewEngine, CompositeViewEngine>();
+            // _ = webApplicationBuilder.Services.AddTransient<IViewRenderingService, ViewRenderingService>();
+            // _ = webApplicationBuilder.Services.AddScoped<IViewRenderService, ViewRenderService>();
+            // _ = webApplicationBuilder.Services.AddSingleton<ITempDataProvider, ITempDataProvider>();
+            _ = webApplicationBuilder.Services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
+            _ = webApplicationBuilder.Services.AddScoped<IAuthenticationService, AuthenticationService>();
+            _ = webApplicationBuilder.Services.AddScoped<IDalService, DalService>();
+            _ = webApplicationBuilder.Services.AddScoped<IDbConnectionService, DbConnectionService>();
+            _ = webApplicationBuilder.Services.AddScoped<IUserService, UserService>();
             _ = webApplicationBuilder.Services.AddSwaggerGen();
             _ = webApplicationBuilder.Services.AddSession(sessionOptions => {
                 sessionOptions.IdleTimeout = TimeSpan.FromSeconds(2000);
@@ -37,6 +69,29 @@ public class Program {
                 sessionOptions.Cookie.IsEssential = true;
             }
             );
+
+            _ = webApplicationBuilder.Services.AddAuthentication(options => {
+                options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
+                options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
+            })
+            .AddJwtBearer(options => {
+                options.RequireHttpsMetadata = false;
+                options.SaveToken = true;
+                options.TokenValidationParameters = new TokenValidationParameters {
+                    ValidateIssuerSigningKey = true,
+                    ValidIssuer = appSettings.JwtIssuer,
+                    ValidateAudience = false,
+                    IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(appSettings.JwtKey)),
+                    ClockSkew = TimeSpan.Zero
+                };
+            });
+
+            _ = webApplicationBuilder.Services.AddAuthorization(options => {
+                options.DefaultPolicy = new AuthorizationPolicyBuilder()
+                                            .AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme)
+                                            .RequireAuthenticatedUser()
+                                            .Build();
+            });
             if (WindowsServiceHelpers.IsWindowsService()) {
                 _ = webApplicationBuilder.Services.AddSingleton<IHostLifetime, WindowsServiceLifetime>();
                 _ = webApplicationBuilder.Logging.AddEventLog(settings => {
@@ -65,6 +120,8 @@ public class Program {
             }
             _ = webApplication.UseSession();
             _ = webApplication.MapControllers();
+            _ = webApplication.UseAuthentication();
+            _ = webApplication.UseAuthorization();
             logger.LogInformation("Starting Web Application");
             webApplication.Run();
             return 0;

Fab2ApprovalMKLink/Services/AuthenticationService.cs

@@ -0,0 +1,266 @@
+using System;
+using System.Collections.Generic;
+using System.DirectoryServices.AccountManagement;
+using System.IdentityModel.Tokens.Jwt;
+using System.Security.Authentication;
+using System.Security.Claims;
+using System.Security.Cryptography;
+using System.Security.Principal;
+using System.Text;
+using System.Threading.Tasks;
+
+using Fab2ApprovalSystem.Models;
+
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging;
+using Microsoft.IdentityModel.Tokens;
+
+namespace Fab2ApprovalSystem.Services;
+
+public interface IAuthenticationService {
+    public Task<LoginResult> AuthenticateUser(AuthAttempt login);
+    public Task<LoginResult> AttemptLocalUserAuth(WindowsIdentity identity);
+    public AuthTokens GenerateAuthTokens(AuthAttempt authAttempt, IEnumerable<string> roles);
+    public Task<LoginResult> RefreshAuthTokens(AuthAttempt authAttempt);
+}
+
+public class AuthenticationService : IAuthenticationService {
+    private readonly ILogger<AuthenticationService> _logger;
+    private readonly IMemoryCache _cache;
+    private readonly IUserService _userService;
+
+    private readonly string? _jwtIssuer;
+    private readonly string? _jwtAudience;
+    private readonly string? _jwtKey;
+
+    public AuthenticationService(ILogger<AuthenticationService> logger, IMemoryCache cache, IUserService userService, AppSettings appSettings) {
+        _logger = logger ?? throw new ArgumentNullException("ILogger not injected");
+        _cache = cache ?? throw new ArgumentNullException("IMemoryCache not injected");
+        _userService = userService ?? throw new ArgumentNullException("IUserService not injected");
+        _jwtKey = appSettings.JwtKey;
+        _jwtIssuer = appSettings.JwtIssuer;
+        _jwtAudience = appSettings.JwtAudience;
+    }
+
+    public async Task<LoginResult> AuthenticateUser(AuthAttempt login) {
+        try {
+            _logger.LogInformation("Attempting to authenticate user");
+
+            if (login is null)
+                throw new ArgumentNullException("Login cannot be null");
+
+            string domain = "infineon.com";
+
+            using (PrincipalContext pc = new(ContextType.Domain, domain)) {
+                bool isValid = pc.ValidateCredentials(login.LoginID, login.Password);
+
+                if (isValid) {
+                    User? user = _cache.Get<User>($"user{login.LoginID}");
+
+                    if (user is null) {
+                        user = await _userService.GetUserByLoginId(login.LoginID);
+
+                        _cache.Set($"user{login.LoginID}", user, DateTimeOffset.Now.AddDays(1));
+                    }
+
+                    List<string> roles = new();
+
+                    if (user.IsManager)
+                        roles.Add("manager");
+                    if (user.IsAdmin)
+                        roles.Add("admin");
+
+                    AuthTokens tokens = GenerateAuthTokens(login, roles);
+
+                    return new LoginResult {
+                        IsAuthenticated = true,
+                        AuthTokens = tokens,
+                        User = user
+                    };
+                } else {
+                    return new LoginResult() {
+                        IsAuthenticated = false,
+                        AuthTokens = new() {
+                            JwtToken = "",
+                            RefreshToken = ""
+                        },
+                        User = null
+                    };
+                }
+            }
+        } catch (Exception ex) {
+            _logger.LogError($"An exception occurred when attempting to authenticate user. Exception: {ex.Message}");
+            throw;
+        }
+    }
+
+    public async Task<LoginResult> AttemptLocalUserAuth(WindowsIdentity identity) {
+        try {
+            _logger.LogInformation("Attempting to authenticate local Windows system user");
+
+            if (identity is null)
+                throw new ArgumentNullException("WindowsIdentity cannot be null");
+
+            User user = await _userService.GetUserByLoginId(identity.Name);
+
+            List<string> roles = new();
+
+            if (user.IsManager)
+                roles.Add("manager");
+            if (user.IsAdmin)
+                roles.Add("admin");
+
+            AuthAttempt authAttempt = new() {
+                LoginID = user.LoginID,
+            };
+
+            AuthTokens tokens = GenerateAuthTokens(authAttempt, roles);
+
+            return new LoginResult {
+                IsAuthenticated = true,
+                AuthTokens = tokens,
+                User = user
+            };
+        } catch (Exception ex) {
+            _logger.LogError($"Unable to authenticate local Windows system user, because {ex.Message}");
+            throw;
+        }
+    }
+
+    public AuthTokens GenerateAuthTokens(AuthAttempt authAttempt, IEnumerable<string> roles) {
+        try {
+            _logger.LogInformation("Attempting to generate JWT");
+
+            if (authAttempt is null)
+                throw new ArgumentNullException("AuthAttempt cannot be null");
+            if (string.IsNullOrWhiteSpace(authAttempt.LoginID))
+                throw new ArgumentException("UserName cannot be null or empty");
+            if (roles is null)
+                throw new ArgumentNullException("roles cannot be null");
+
+            byte[] key = Encoding.ASCII.GetBytes(_jwtKey);
+
+            List<Claim> claims = new() {
+                new Claim(nameof(authAttempt.LoginID), authAttempt.LoginID)
+            };
+
+            foreach (string role in roles) {
+                claims.Add(new Claim(ClaimTypes.Role, role));
+            }
+
+            ClaimsIdentity identity = new(claims);
+
+            SecurityTokenDescriptor tokenDescriptor = new() {
+                Issuer = _jwtIssuer,
+                Audience = _jwtAudience,
+                Subject = identity,
+                NotBefore = DateTime.Now,
+                Expires = DateTime.Now.AddHours(8),
+                SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature)
+            };
+
+            JwtSecurityTokenHandler tokenHandler = new();
+
+            JwtSecurityToken token = tokenHandler.CreateJwtSecurityToken(tokenDescriptor);
+
+            string jwt = tokenHandler.WriteToken(token);
+
+            string refreshToken = GenerateRefreshToken();
+
+            List<string>? refreshTokensForUser = _cache.Get<List<string>>(authAttempt.LoginID);
+
+            refreshTokensForUser ??= new List<string>();
+
+            if (refreshTokensForUser.Count > 9)
+                refreshTokensForUser.RemoveRange(9, refreshTokensForUser.Count - 9);
+
+            refreshTokensForUser.Insert(0, refreshToken);
+
+            _cache.Set(authAttempt.LoginID, refreshTokensForUser, DateTimeOffset.Now.AddHours(4));
+
+            return new AuthTokens {
+                JwtToken = jwt,
+                RefreshToken = refreshToken
+            };
+        } catch (Exception ex) {
+            _logger.LogError($"An exception occurred when attempting to generate JWT. Exception: {ex.Message}");
+            throw;
+        }
+    }
+
+    public async Task<LoginResult> RefreshAuthTokens(AuthAttempt authAttempt) {
+        try {
+            _logger.LogInformation("Attempting to refresh auth tokens");
+
+            if (authAttempt is null)
+                throw new ArgumentNullException("AuthAttempt cannot be null");
+            if (authAttempt.AuthTokens is null)
+                throw new ArgumentNullException("AuthTokens cannot be null");
+
+            bool refreshTokenIsValid = IsRefreshTokenValid(authAttempt.LoginID, authAttempt.AuthTokens.RefreshToken);
+
+            if (refreshTokenIsValid) {
+                User? user = _cache.Get<User>($"user{authAttempt.LoginID}");
+
+                if (user is null) {
+                    user = await _userService.GetUserByLoginId(authAttempt.LoginID);
+
+                    _cache.Set($"user{authAttempt.LoginID}", user, DateTimeOffset.Now.AddDays(1));
+                }
+
+                List<string> roles = new();
+
+                if (user.IsManager)
+                    roles.Add("manager");
+                if (user.IsAdmin)
+                    roles.Add("admin");
+
+                AuthTokens refreshedTokens = GenerateAuthTokens(authAttempt, roles);
+
+                LoginResult loginResult = new() {
+                    IsAuthenticated = true,
+                    AuthTokens = refreshedTokens,
+                    User = user
+                };
+
+                return loginResult;
+            } else {
+                throw new AuthenticationException("Invalid refresh token");
+            }
+        } catch (Exception ex) {
+            _logger.LogError($"An exception occurred when attempting to refresh auth tokens. Exception: {ex.Message}");
+            throw;
+        }
+    }
+
+    private string GenerateRefreshToken() {
+        byte[] randomNumber = new byte[32];
+        using (RandomNumberGenerator rng = RandomNumberGenerator.Create()) {
+            rng.GetBytes(randomNumber);
+            return Convert.ToBase64String(randomNumber);
+        }
+    }
+
+    private bool IsRefreshTokenValid(string loginId, string refreshToken) {
+        try {
+            _logger.LogInformation("Attempting to determine if refresh token is valid");
+
+            if (string.IsNullOrWhiteSpace(loginId))
+                throw new ArgumentNullException("LoginID cannot be null or empty");
+            if (string.IsNullOrWhiteSpace(refreshToken))
+                throw new ArgumentNullException("Refresh token cannot be null or empty");
+
+            List<string>? cachedRefreshTokensForUser = _cache.Get<List<string>>(loginId);
+
+            if (cachedRefreshTokensForUser is null || !cachedRefreshTokensForUser.Contains(refreshToken)) {
+                _logger.LogInformation($"Could not find cached refresh tokens for user {loginId}");
+                return false;
+            }
+
+            return true;
+        } catch (Exception ex) {
+            _logger.LogError($"An exception occurred when attempting to validate refresh token. Exception: {ex.Message}");
+            throw;
+        }
+    }
+}

Fab2ApprovalMKLink/Services/DalService.cs

@@ -0,0 +1,168 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Text;
+using System.Threading.Tasks;
+
+using Dapper;
+
+using Microsoft.Extensions.Logging;
+
+namespace Fab2ApprovalSystem.Services;
+
+public interface IDalService {
+    Task<IEnumerable<T>> QueryAsync<T>(string sql);
+    Task<IEnumerable<T>> QueryAsync<T>(string sql, object parameters);
+    Task<int> ExecuteAsync(string sql);
+    Task<int> ExecuteAsync<T>(string sql, T parameters);
+}
+
+public class DalService : IDalService {
+    private static readonly int RETRIES = 3;
+    private static readonly int BACKOFF_SECONDS_INTERVAL = 30;
+
+    private readonly ILogger<DalService> _logger;
+    private readonly IDbConnectionService _dbConnectionService;
+
+    public DalService(IDbConnectionService dbConnectionService, ILogger<DalService> logger) {
+        _dbConnectionService = dbConnectionService ??
+            throw new ArgumentNullException("IDbConnectionService not injected");
+        _logger = logger ??
+            throw new ArgumentNullException("ILogger not injected");
+    }
+
+    public async Task<IEnumerable<T>> QueryAsync<T>(string sql) {
+        if (sql is null) throw new ArgumentNullException("sql cannot be null");
+
+        int remainingRetries = RETRIES;
+        bool queryWasSuccessful = false;
+        Exception exception = null;
+        IEnumerable<T> result = new List<T>();
+        while (!queryWasSuccessful && remainingRetries > 0) {
+            int backoffSeconds = (RETRIES - remainingRetries--) * BACKOFF_SECONDS_INTERVAL;
+            Task.Delay(backoffSeconds * 1000).Wait();
+
+            try {
+                _logger.LogInformation($"Attempting to perform query with {sql}. Remaining retries: {remainingRetries}");
+
+                using (IDbConnection conn = _dbConnectionService.GetConnection()) {
+                    result = await conn.QueryAsync<T>(sql);
+                }
+
+                queryWasSuccessful = true;
+            } catch (Exception ex) {
+                _logger.LogError($"An exception occurred while attempting to perform a query. Exception: {ex.Message}");
+                exception = ex;
+            }
+        }
+
+        if (!queryWasSuccessful && exception is not null) {
+            throw exception;
+        }
+
+        return result;
+    }
+
+    public async Task<IEnumerable<T>> QueryAsync<T>(string sql, object parameters) {
+        if (sql is null) throw new ArgumentNullException("sql cannot be null");
+        if (parameters is null) throw new ArgumentNullException("parameters cannot be null");
+
+        StringBuilder logBuilder = new();
+
+        int remainingRetries = RETRIES;
+        bool queryWasSuccessful = false;
+        Exception exception = null;
+        IEnumerable<T> result = new List<T>();
+        while (!queryWasSuccessful && remainingRetries > 0) {
+            int backoffSeconds = (RETRIES - remainingRetries--) * BACKOFF_SECONDS_INTERVAL;
+            Task.Delay(backoffSeconds * 1000).Wait();
+
+            try {
+                logBuilder.Clear();
+                logBuilder.Append($"Attempting to perform query with {sql} ");
+                logBuilder.Append($"and parameters {parameters.ToString()}. ");
+                logBuilder.Append($"Remaining retries: {remainingRetries}");
+                _logger.LogInformation(logBuilder.ToString());
+
+                using (IDbConnection conn = _dbConnectionService.GetConnection()) {
+                    result = await conn.QueryAsync<T>(sql, parameters);
+                }
+
+                queryWasSuccessful = true;
+            } catch (Exception ex) {
+                _logger.LogError($"An exception occurred while attempting to perform a query. Exception: {ex.Message}");
+                exception = ex;
+            }
+        }
+
+        if (!queryWasSuccessful && exception is not null) {
+            throw exception;
+        }
+
+        return result;
+    }
+
+    public async Task<int> ExecuteAsync(string sql) {
+        if (sql is null) throw new ArgumentNullException("sql cannot be null");
+
+        int remainingRetries = RETRIES;
+        bool queryWasSuccessful = false;
+        Exception exception = null;
+        int rowsAffected = 0;
+        while (!queryWasSuccessful && remainingRetries > 0) {
+            int backoffSeconds = (RETRIES - remainingRetries--) * BACKOFF_SECONDS_INTERVAL;
+            Task.Delay(backoffSeconds * 1000).Wait();
+
+            try {
+                _logger.LogInformation($"Attempting to execute {sql}. Remaining retries: {remainingRetries}");
+
+                using (IDbConnection conn = _dbConnectionService.GetConnection()) {
+                    rowsAffected = await conn.ExecuteAsync(sql);
+                }
+
+                queryWasSuccessful = true;
+            } catch (Exception ex) {
+                _logger.LogError($"An exception occurred while attempting to execute a query. Exception: {ex.Message}");
+                exception = ex;
+            }
+        }
+
+        if (!queryWasSuccessful && exception is not null) {
+            throw exception;
+        }
+
+        return rowsAffected;
+    }
+
+    public async Task<int> ExecuteAsync<T>(string sql, T parameters) {
+        if (sql is null) throw new ArgumentNullException("sql cannot be null");
+
+        int remainingRetries = RETRIES;
+        bool queryWasSuccessful = false;
+        Exception exception = null;
+        int rowsAffected = 0;
+        while (!queryWasSuccessful && remainingRetries > 0) {
+            int backoffSeconds = (RETRIES - remainingRetries--) * BACKOFF_SECONDS_INTERVAL;
+            Task.Delay(backoffSeconds * 1000).Wait();
+
+            try {
+                _logger.LogInformation($"Attempting to execute {sql} with parameters. Remaining retries: {remainingRetries}");
+
+                using (IDbConnection conn = _dbConnectionService.GetConnection()) {
+                    rowsAffected = await conn.ExecuteAsync(sql, parameters);
+                }
+
+                queryWasSuccessful = true;
+            } catch (Exception ex) {
+                _logger.LogError($"An exception occurred while attempting to execute a query. Exception: {ex.Message}");
+                exception = ex;
+            }
+        }
+
+        if (!queryWasSuccessful && exception is not null) {
+            throw exception;
+        }
+
+        return rowsAffected;
+    }
+}

Fab2ApprovalMKLink/Services/DbConnectionService.cs

@@ -0,0 +1,22 @@
+using System.Data;
+
+using Fab2ApprovalSystem.Models;
+
+using Microsoft.Data.SqlClient;
+
+namespace Fab2ApprovalSystem.Services;
+
+public interface IDbConnectionService {
+    IDbConnection GetConnection();
+}
+
+public class DbConnectionService : IDbConnectionService {
+    private readonly string _dbConnectionString;
+
+    public DbConnectionService(AppSettings appSettings) {
+        _dbConnectionString = appSettings.DBConnectionString;
+    }
+
+    public IDbConnection GetConnection() =>
+        new SqlConnection(_dbConnectionString);
+}

Fab2ApprovalMKLink/Services/UserService.cs

@@ -0,0 +1,150 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+using Fab2ApprovalSystem.Models;
+
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Logging;
+
+namespace Fab2ApprovalSystem.Services;
+
+public interface IUserService {
+    Task<IEnumerable<User>> GetAllActiveUsers();
+    Task<User> GetUserByLoginId(string loginId);
+    Task<User> GetUserByUserId(int userId);
+    Task<IEnumerable<int>> GetApproverUserIdsBySubRoleCategoryItem(string item);
+}
+
+public class UserService : IUserService {
+    private readonly ILogger<UserService> _logger;
+    private readonly IDalService _dalService;
+    private readonly IMemoryCache _cache;
+
+    public UserService(ILogger<UserService> logger, IDalService dalService, IMemoryCache cache) {
+        _logger = logger ??
+            throw new ArgumentNullException("ILogger not injected");
+        _dalService = dalService ??
+            throw new ArgumentNullException("IDalService not injected");
+        _cache = cache ??
+            throw new ArgumentNullException("IMemoryCache not injected");
+    }
+
+    public async Task<IEnumerable<User>> GetAllActiveUsers() {
+        try {
+            _logger.LogInformation("Attempting to get all active users");
+
+            IEnumerable<User>? allActiveUsers = _cache.Get<IEnumerable<User>>("allActiveUsers");
+
+            if (allActiveUsers is null) {
+                string sql = "select * from Users where IsActive = 1";
+
+                allActiveUsers = (await _dalService.QueryAsync<User>(sql)).ToList();
+
+                _cache.Set("allActiveUsers", allActiveUsers, DateTimeOffset.Now.AddHours(1));
+            }
+
+            if (allActiveUsers is null || allActiveUsers.Count() == 0) {
+                throw new Exception("No users found");
+            }
+
+            return allActiveUsers;
+        } catch (Exception ex) {
+            string errMsg = $"An exception occurred when attempting to get all users. Exception: {ex.Message}";
+            _logger.LogError(errMsg);
+            throw;
+        }
+    }
+
+    public async Task<User> GetUserByLoginId(string loginId) {
+        try {
+            _logger.LogInformation("Attempting to get user by LoginId");
+
+            if (string.IsNullOrWhiteSpace(loginId))
+                throw new ArgumentException("LoginId cannot be null or empty");
+
+            User? user = _cache.Get<User>($"userByLoginId{loginId}");
+
+            user ??= _cache.Get<IEnumerable<User>>("allActiveUsers")?.FirstOrDefault(u => u.LoginID == loginId);
+
+            if (user is null) {
+                string sql = $"select * from Users where LoginID = '{loginId}';";
+
+                user = (await _dalService.QueryAsync<User>(sql)).FirstOrDefault();
+
+                _cache.Set($"userByLoginId{loginId}", user, DateTimeOffset.Now.AddHours(1));
+            }
+
+            if (user is null) throw new Exception($"No user found with LoginID {loginId}");
+
+            return user;
+        } catch (Exception ex) {
+            string errMsg = $"An exception occurred when attempting to get user for LoginID {loginId}. Exception: {ex.Message}";
+            _logger.LogError(errMsg);
+            throw;
+        }
+    }
+
+    public async Task<User> GetUserByUserId(int userId) {
+        try {
+            _logger.LogInformation("Attempting to get user by user ID");
+
+            if (userId <= 0) throw new ArgumentException($"{userId} is not a valid user ID");
+
+            User? user = _cache.Get<User>($"userByUserId{userId}");
+
+            user ??= _cache.Get<IEnumerable<User>>("allActiveUsers")?.FirstOrDefault(u => u.UserID == userId);
+
+            if (user is null) {
+                string sql = $"select * from Users where UserID = '{userId}';";
+
+                user = (await _dalService.QueryAsync<User>(sql)).FirstOrDefault();
+
+                _cache.Set($"userByUserId{userId}", user, DateTimeOffset.Now.AddHours(1));
+            }
+
+            if (user is null) throw new Exception($"No user found with UserID {userId}");
+
+            return user;
+        } catch (Exception ex) {
+            string errMsg = $"An exception occurred when attempting to get user for UserID {userId}. Exception: {ex.Message}";
+            _logger.LogError(errMsg);
+            throw;
+        }
+    }
+
+    public async Task<IEnumerable<int>> GetApproverUserIdsBySubRoleCategoryItem(string item) {
+        try {
+            _logger.LogInformation("Attempting to get approver user IDs");
+
+            if (string.IsNullOrWhiteSpace(item)) throw new ArgumentException("SubRoleCategoryItem cannot be null or empty");
+
+            IEnumerable<int>? userIds = _cache.Get<IEnumerable<int>>($"approverUserIdsBySubRollCategory{item}");
+
+            if (userIds is null) {
+                StringBuilder queryBuilder = new();
+                queryBuilder.Append("select us.UserID ");
+                queryBuilder.Append("from SubRole as sr ");
+                queryBuilder.Append("join UserSubRole as us on sr.SubRoleID=us.SubRoleID ");
+                queryBuilder.Append("join SubRoleCategory as sc on sr.SubRoleCategoryID=sc.SubRoleCategoryID ");
+                queryBuilder.Append($"where sc.SubRoleCategoryItem='{item}'");
+
+                userIds = (await _dalService.QueryAsync<int>(queryBuilder.ToString())).ToList();
+
+                _cache.Set($"approverUserIdsBySubRollCategory{item}", userIds, DateTimeOffset.Now.AddHours(1));
+            }
+
+            if (userIds is null || userIds.Count() == 0) {
+                throw new Exception($"No users found for SubRoleCategoryItem {item}");
+            }
+
+            return userIds;
+        } catch (Exception ex) {
+            string errMsg = $"An exception occurred when attempting to get approver user IDs. Exception: {ex.Message}";
+            _logger.LogError(errMsg);
+            throw;
+        }
+    }
+}

Fab2ApprovalMKLink/Views/_ViewImports.cshtml

@@ -0,0 +1,8 @@
+@using Fab2ApprovalSystem.DMO
+@using Fab2ApprovalSystem.JobSchedules
+@using Fab2ApprovalSystem.Misc
+@using Fab2ApprovalSystem.Models
+@using Fab2ApprovalSystem.PdfGenerator
+@using Fab2ApprovalSystem.Utilities
+@using Fab2ApprovalSystem.ViewModels
+@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

Fab2ApprovalMKLink/Views/_ViewStart.cshtml

@@ -0,0 +1,3 @@
+@{
+    Layout = null;
+}