initial commit

Migrations/20220917022529_InitialCreate.cs

@@ -0,0 +1,38 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace UrlShortener.Migrations
+{
+    public partial class InitialCreate : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "Urls",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "TEXT", nullable: false),
+                    Path = table.Column<string>(type: "TEXT", nullable: false),
+                    Destination = table.Column<string>(type: "TEXT", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Urls", x => x.Id);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Urls_Path",
+                table: "Urls",
+                column: "Path",
+                unique: true);
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "Urls");
+        }
+    }
+}

Migrations/UrlShortenerDbContextModelSnapshot.cs

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+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace UrlShortener.Migrations
+{
+    [DbContext(typeof(UrlShortenerDbContext))]
+    partial class UrlShortenerDbContextModelSnapshot : ModelSnapshot
+    {
+        protected override void BuildModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "6.0.9");
+
+            modelBuilder.Entity("Url", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Destination")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Path")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Path")
+                        .IsUnique();
+
+                    b.ToTable("Urls");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

Program.cs

@@ -0,0 +1,104 @@
+using System.ComponentModel.DataAnnotations;
+using System.Text.Json.Nodes;
+using System.Text.RegularExpressions;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+
+var builder = WebApplication.CreateBuilder(args);
+
+builder.Services.AddDbContext<UrlShortenerDbContext>(options =>
+    options.UseSqlite(builder.Configuration.GetConnectionString($"UrlDb")));
+
+var app = builder.Build();
+
+app.UseDefaultFiles()
+    .UseStaticFiles();
+
+string AbsoluteUrl(HttpRequest request, string path)
+    => $"{request.Scheme}://{request.Host}{request.PathBase}{path}";
+
+var pathRegex = new Regex(
+    "^[a-zA-Z0-9_]*$",
+    RegexOptions.None,
+    TimeSpan.FromMilliseconds(1)
+);
+
+app.MapPost("/api/urls", async (
+    HttpRequest request,
+    UrlShortenerDbContext dbContext
+) =>
+{
+    var jsonObject = await request.ReadFromJsonAsync<JsonObject>();
+    var path = jsonObject?["path"]?.GetValue<string?>()?.Trim('/');
+    var destination = jsonObject?["destination"]?.GetValue<string?>();
+
+    if (string.IsNullOrEmpty(path))
+        return Results.Problem("Path cannot be empty.");
+
+    if (path.Length > 10)
+        return Results.Problem("Path cannot be longer than 10 characters.");
+
+    if (pathRegex.IsMatch(path) == false)
+        return Results.Problem("Path can only contain alphanumeric characters and underscores.");
+
+    if (string.IsNullOrEmpty(destination))
+        return Results.Problem("Destination cannot be empty.");
+
+    if (!Uri.IsWellFormedUriString(destination, UriKind.Absolute))
+        return Results.Problem("Destination has to be a valid absolute URL.");
+
+    if (dbContext.Urls.Any(u => u.Path.Equals(path)))
+        return Results.Problem("Path is already in use.");
+
+    var url = new Url {Path = path, Destination = destination};
+    await dbContext.Urls.AddAsync(url);
+    await dbContext.SaveChangesAsync();
+
+    return Results.Created(
+        uri: new Uri(AbsoluteUrl(request, $"/api/urls/{url.Path}")),
+        value: new
+        {
+            Path = url.Path,
+            Destination = url.Destination,
+            Id = url.Id,
+            ShortenedUrl = AbsoluteUrl(request, $"/{url.Path}")
+        }
+    );
+});
+
+app.MapGet("/{path}", async (
+    string path,
+    UrlShortenerDbContext dbContext
+) =>
+{
+    if (string.IsNullOrEmpty(path) ||
+        path.Length > 10 ||
+        pathRegex.IsMatch(path) == false)
+        return Results.BadRequest();
+
+    var url = await dbContext.Urls.FirstOrDefaultAsync(u => u.Path == path);
+    if (url == null)
+        return Results.NotFound();
+
+    return Results.Redirect(url.Destination);
+});
+
+app.Run();
+
+public sealed class UrlShortenerDbContext : DbContext
+{
+    public DbSet<Url> Urls { get; set; }
+
+    public UrlShortenerDbContext(DbContextOptions<UrlShortenerDbContext> options)
+        : base(options)
+    {
+    }
+}
+
+[Index(nameof(Path), IsUnique = true)]
+public sealed record Url
+{
+    public Guid Id { get; set; }
+    public string Path { get; set; }
+    public string Destination { get; set; }
+}

Properties/launchSettings.json

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+{
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "http://localhost:5063",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "https://localhost:7205;http://localhost:5063",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

UrlShortener.csproj

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+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net7.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="6.0.9">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="6.0.9" />
+  </ItemGroup>
+
+</Project>

appsettings.Development.json

@@ -0,0 +1,11 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "ConnectionStrings": {
+    "UrlDb": "Data Source=urls.db"
+  }
+}

appsettings.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}

wwwroot/index.html

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+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>URL Shortener</title>
+</head>
+<body>
+<form>
+    <div>
+        <label for="destination">Destination URL</label>
+        <input type="text" id="destination" name="destination">
+    </div>
+    <div>
+        <label for="path">Short Path</label>
+        <input id="path" name="path">
+    </div>
+    <button type="submit">Shorten URL</button>
+</form>
+<div style="display: none">
+    Shortened URL created: <br>
+    <label for="result">Shortened URL</label>
+    <input readonly id="result">
+</div>
+<script>
+    const resultInput = document.getElementById('result');
+    const resultParent = resultInput.parentElement;
+    const form = document.getElementsByTagName('form')[0];
+    form.addEventListener('submit', async (event) => {
+        event.preventDefault();
+        const url = {
+            destination: form['destination'].value,
+            path: form['path'].value
+        };
+        fetch('/api/urls', {
+            method: 'POST', // *GET, POST, PUT, DELETE, etc.
+            headers: {
+                'Content-Type': 'application/json'
+            },
+            body: JSON.stringify(url)
+        })
+            .then(async response => {
+                const responseObject = await response.json()
+                if (!response.ok) {
+                    console.error(responseObject)
+                    return;
+                }
+
+                resultInput.value = responseObject.shortenedUrl;
+                resultParent.style.display = 'block';
+            });
+    });
+</script>
+</body>
+</html>