Add login function in backend

backend/ApplicationState.cs

@@ -6,6 +6,6 @@ namespace backend.Application
 	public static class ApplicationState
 	{
 		public static IMqttClient? MqttClient { get; set; }
-		public static DbContext? DbContext { get; set; }
+		public static DispenserContext? DbContext { get; set; }
 	}
 }

backend/Controllers/UserController.cs

@@ -3,6 +3,7 @@ using backend.Application;
 using backend.Models;
 using System.Text.Json.Nodes;
 using Microsoft.AspNetCore.Identity;
+using System.Web;
 
 namespace backend.Controllers;
 
@@ -12,24 +13,29 @@ public class UserController : ControllerBase
 	[HttpPost("Register")]
 	public IActionResult Register([FromBody] JsonObject input)
 	{
-        if (input["username"] == null || input["password"] == null) {
+		// Validate
+		if (String.IsNullOrEmpty(input["username"]?.ToString()) || String.IsNullOrEmpty(input["password"]?.ToString())) {
 			return BadRequest("Username and password required");
 		}
 
+		// Hash password
 		var passwordHasher = new PasswordHasher<object>();
 		string hashedPassword = passwordHasher.HashPassword(null, input["password"]!.ToString());
 
+		// Generate touch code
 		string touchCode = "";
 		for (int i = 0; i < 4; i++) {
 			touchCode += (1 + new Random().Next() % 5).ToString();
 		}
 
+		// Create user
 		var user = new User {
 			Username = input["username"]!.ToString(),
 			Password = hashedPassword,
 			TouchCode = touchCode,
 		};
 
+		// Save user
 		ApplicationState.DbContext!.Add(user);
 		ApplicationState.DbContext!.SaveChanges();
 
@@ -37,4 +43,42 @@ public class UserController : ControllerBase
 
 		return Ok();
 	}
+
+	[HttpPost("Login")]
+	public IActionResult Login([FromBody] JsonObject input)
+	{
+		// Validate
+		if (String.IsNullOrEmpty(input["username"]?.ToString()) || String.IsNullOrEmpty(input["password"]?.ToString())) {
+			return BadRequest("Username and password required");
+		}
+
+		if (Request.Cookies["session"] != null) {
+			return BadRequest("You are already logged in");
+		}
+
+		// Get user
+		var user = ApplicationState.DbContext!.Users.FirstOrDefault(user => user.Username == input["username"]!.ToString());
+		if (user == null) {
+			return BadRequest("Invalid username");
+		}
+
+		// Verify password
+		var passwordHasher = new PasswordHasher<object>();
+		if (passwordHasher.VerifyHashedPassword(null, user.Password, input["password"]!.ToString()) == PasswordVerificationResult.Failed) {
+			return BadRequest("Invalid password");
+		}
+
+		// Create session token if necessary
+		if (string.IsNullOrEmpty(user.SessionToken)) {
+			user.SessionToken = Guid.NewGuid().ToString();
+			ApplicationState.DbContext!.SaveChanges();
+		}
+
+		// Set session cookie
+		Response.Cookies.Append("session", user.SessionToken);
+
+		Console.WriteLine(user.Username + " has logged in");
+
+		return Ok();
+	}
 }

backend/Migrations/20231207234050_AddSessionTokenToUser.Designer.cs

@@ -0,0 +1,64 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace backend.Migrations
+{
+    [DbContext(typeof(DispenserContext))]
+    [Migration("20231207234050_AddSessionTokenToUser")]
+    partial class AddSessionTokenToUser
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "8.0.0");
+
+            modelBuilder.Entity("backend.Models.DispenserLog", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("Timestamp")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("DispenserLogs");
+                });
+
+            modelBuilder.Entity("backend.Models.User", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Password")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("SessionToken")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("TouchCode")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Username")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Users");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

backend/Migrations/20231207234050_AddSessionTokenToUser.cs

@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace backend.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddSessionTokenToUser : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "SessionToken",
+                table: "Users",
+                type: "TEXT",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "SessionToken",
+                table: "Users");
+        }
+    }
+}

backend/Migrations/DispenserContextModelSnapshot.cs

@@ -40,6 +40,9 @@ namespace backend.Migrations
                         .IsRequired()
                         .HasColumnType("TEXT");
 
+                    b.Property<string>("SessionToken")
+                        .HasColumnType("TEXT");
+
                     b.Property<string>("TouchCode")
                         .IsRequired()
                         .HasColumnType("TEXT");

backend/Models/User.cs

@@ -12,4 +12,5 @@ public class User
 	public string Username { get; set; }
     public string Password { get; set; }
     public string TouchCode { get; set; }
+	public string? SessionToken { get; set; }
 }