feat: add import from azure app configuration (#69)

src/AzureAppConfigurationEmulator.Authentication.Hmac/HmacAuthenticatingHttpMessageHandler.cs

@@ -0,0 +1,72 @@
+using System.Net.Http.Headers;
+using System.Security.Cryptography;
+using System.Text;
+
+namespace AzureAppConfigurationEmulator.Authentication.Hmac;
+
+public class HmacAuthenticatingHttpMessageHandler(string credential, string secret) : DelegatingHandler
+{
+    protected override async Task<HttpResponseMessage> SendAsync(
+        HttpRequestMessage request,
+        CancellationToken cancellationToken)
+    {
+        using var activity = Telemetry.ActivitySource.StartActivity($"{nameof(HmacAuthenticatingHttpMessageHandler)}.{nameof(SendAsync)}");
+
+        var contentHash = await ComputeContentHash(request, cancellationToken);
+        activity?.SetTag(Telemetry.ContentHash, contentHash);
+
+        var date = DateTimeOffset.UtcNow;
+        activity?.SetTag(Telemetry.Date, date);
+
+        request.Headers.Authorization = GetAuthenticationHeaderValue(request, contentHash, date);
+        request.Headers.Date = date;
+        request.Headers.Add("x-ms-content-sha256", contentHash);
+
+        return await base.SendAsync(request, cancellationToken);
+    }
+
+    private static async Task<string> ComputeContentHash(
+        HttpRequestMessage request,
+        CancellationToken cancellationToken = default)
+    {
+        using var activity = Telemetry.ActivitySource.StartActivity($"{nameof(HmacAuthenticatingHttpMessageHandler)}.{nameof(ComputeContentHash)}");
+
+        using var stream = new MemoryStream();
+
+        if (request.Content is not null)
+        {
+            await request.Content.CopyToAsync(stream, cancellationToken);
+        }
+
+        using var sha256 = SHA256.Create();
+
+        return Convert.ToBase64String(await sha256.ComputeHashAsync(stream, cancellationToken));
+    }
+
+    private string ComputeHash(string value)
+    {
+        using var activity = Telemetry.ActivitySource.StartActivity($"{nameof(HmacAuthenticatingHttpMessageHandler)}.{nameof(ComputeHash)}");
+
+        using var hmac = new HMACSHA256(Convert.FromBase64String(secret));
+
+        return Convert.ToBase64String(hmac.ComputeHash(Encoding.ASCII.GetBytes(value)));
+    }
+
+    private AuthenticationHeaderValue GetAuthenticationHeaderValue(
+        HttpRequestMessage request,
+        string contentHash,
+        DateTimeOffset date)
+    {
+        using var activity = Telemetry.ActivitySource.StartActivity($"{nameof(HmacAuthenticatingHttpMessageHandler)}.{nameof(GetAuthenticationHeaderValue)}");
+
+        const string signedHeaders = "date;host;x-ms-content-sha256";
+
+        var stringToSign = $"{request.Method.Method.ToUpper()}\n{request.RequestUri?.PathAndQuery}\n{date:R};{request.RequestUri?.Authority};{contentHash}";
+        activity?.SetTag(Telemetry.StringToSign, stringToSign);
+
+        var signature = ComputeHash(stringToSign);
+        activity?.SetTag(Telemetry.Signature, signature);
+
+        return new AuthenticationHeaderValue("HMAC-SHA256", $"Credential={credential}&SignedHeaders={signedHeaders}&Signature={signature}");
+    }
+}

src/AzureAppConfigurationEmulator.Authentication.Hmac/Telemetry.cs

@@ -0,0 +1,15 @@
+using System.Diagnostics;
+
+namespace AzureAppConfigurationEmulator.Authentication.Hmac;
+
+public static class Telemetry
+{
+    public const string ContentHash = $"{Namespace}.content_hash";
+    public const string Date = $"{Namespace}.date";
+    public const string Signature = $"{Namespace}.signature";
+    public const string StringToSign = $"{Namespace}.string_to_sign";
+
+    private const string Namespace = "azure_app_configuration_emulator.authentication.hmac";
+
+    public static ActivitySource ActivitySource { get; } = new("AzureAppConfigurationEmulator.Authentication.Hmac");
+}

src/AzureAppConfigurationEmulator.Common/Abstractions/IConfigurationClient.cs

@@ -0,0 +1,19 @@
+using AzureAppConfigurationEmulator.Common.Constants;
+using AzureAppConfigurationEmulator.Common.Models;
+
+namespace AzureAppConfigurationEmulator.Common.Abstractions;
+
+public interface IConfigurationClient
+{
+    public IAsyncEnumerable<ConfigurationSetting> GetConfigurationSettings(
+        string key = KeyFilter.Any,
+        string label = LabelFilter.Any,
+        DateTimeOffset? moment = default,
+        CancellationToken cancellationToken = default);
+
+    public IAsyncEnumerable<string> GetKeys(
+        CancellationToken cancellationToken = default);
+
+    public IAsyncEnumerable<string?> GetLabels(
+        CancellationToken cancellationToken = default);
+}

src/AzureAppConfigurationEmulator.Common/Clients/ConfigurationClient.cs

@@ -0,0 +1,133 @@
+using System.Runtime.CompilerServices;
+using System.Text.Json;
+using AzureAppConfigurationEmulator.Common.Abstractions;
+using AzureAppConfigurationEmulator.Common.Constants;
+using AzureAppConfigurationEmulator.Common.Headers;
+using AzureAppConfigurationEmulator.Common.Models;
+
+namespace AzureAppConfigurationEmulator.Common.Clients;
+
+public class ConfigurationClient(
+    HttpClient httpClient,
+    IConfigurationSettingFactory configurationSettingFactory) : IConfigurationClient
+{
+    public async IAsyncEnumerable<ConfigurationSetting> GetConfigurationSettings(
+        string key = KeyFilter.Any,
+        string label = LabelFilter.Any,
+        DateTimeOffset? moment = default,
+        [EnumeratorCancellation] CancellationToken cancellationToken = default)
+    {
+        using var activity = Telemetry.ActivitySource.StartActivity($"{nameof(ConfigurationClient)}.{nameof(GetConfigurationSettings)}");
+
+        LinkHeaderValue? link = null;
+
+        do
+        {
+            var uri = link?.Next?.SingleOrDefault() ??
+                      new Uri($"/kv?key={key}&label={label}&api-version=1.0", UriKind.Relative);
+
+            using var request = new HttpRequestMessage(HttpMethod.Get, uri);
+
+            if (moment.HasValue)
+            {
+                request.Headers.Add("Accept-Datetime", moment.Value.ToString("R"));
+            }
+
+            using var response = await httpClient.SendAsync(request, cancellationToken);
+
+            response.EnsureSuccessStatusCode();
+
+            link = response.Headers.TryGetValues("Link", out var values)
+                ? LinkHeaderValue.Parse(string.Join(", ", values))
+                : null;
+
+            await using var stream = await response.Content.ReadAsStreamAsync(cancellationToken);
+            using var document = await JsonDocument.ParseAsync(stream, cancellationToken: cancellationToken);
+
+            foreach (var element in document.RootElement.GetProperty("items").EnumerateArray())
+            {
+                yield return configurationSettingFactory.Create(
+                    element.GetProperty("etag").GetString()!,
+                    element.GetProperty("key").GetString()!,
+                    element.GetProperty("last_modified").GetDateTimeOffset(),
+                    element.GetProperty("locked").GetBoolean(),
+                    element.TryGetProperty("label", out var labelElement)
+                        ? labelElement.GetString()
+                        : null,
+                    element.TryGetProperty("content_type", out var contentTypeElement)
+                        ? contentTypeElement.GetString()
+                        : null,
+                    element.TryGetProperty("value", out var valueElement)
+                        ? valueElement.GetString()
+                        : null,
+                    element.TryGetProperty("tags", out var tagsElement)
+                        ? tagsElement.EnumerateObject().ToDictionary(
+                            property => property.Name,
+                            property => property.Value.GetString()!)
+                        : null);
+            }
+        } while (link is { Next: not null });
+    }
+
+    public async IAsyncEnumerable<string> GetKeys(
+        [EnumeratorCancellation] CancellationToken cancellationToken = default)
+    {
+        using var activity = Telemetry.ActivitySource.StartActivity($"{nameof(ConfigurationClient)}.{nameof(GetKeys)}");
+
+        LinkHeaderValue? link = null;
+
+        do
+        {
+            var uri = link?.Next?.SingleOrDefault() ??
+                      new Uri("/keys?api-version=1.0", UriKind.Relative);
+
+            using var request = new HttpRequestMessage(HttpMethod.Get, uri);
+            using var response = await httpClient.SendAsync(request, cancellationToken);
+
+            response.EnsureSuccessStatusCode();
+
+            link = response.Headers.TryGetValues("Link", out var values)
+                ? LinkHeaderValue.Parse(string.Join(", ", values))
+                : null;
+
+            await using var stream = await response.Content.ReadAsStreamAsync(cancellationToken);
+            using var document = await JsonDocument.ParseAsync(stream, cancellationToken: cancellationToken);
+
+            foreach (var element in document.RootElement.GetProperty("items").EnumerateArray())
+            {
+                yield return element.GetProperty("name").GetString()!;
+            }
+        } while (link is { Next: not null });
+    }
+
+    public async IAsyncEnumerable<string?> GetLabels(
+        [EnumeratorCancellation] CancellationToken cancellationToken = default)
+    {
+        using var activity = Telemetry.ActivitySource.StartActivity($"{nameof(ConfigurationClient)}.{nameof(GetLabels)}");
+
+        LinkHeaderValue? link = null;
+
+        do
+        {
+            var uri = link?.Next?.SingleOrDefault() ??
+                      new Uri("/labels?api-version=1.0", UriKind.Relative);
+
+            using var request = new HttpRequestMessage(HttpMethod.Get, uri);
+            using var response = await httpClient.SendAsync(request, cancellationToken);
+
+            response.EnsureSuccessStatusCode();
+
+            link = response.Headers.TryGetValues("Link", out var values)
+                ? LinkHeaderValue.Parse(string.Join(", ", values))
+                : null;
+
+            await using var stream = await response.Content.ReadAsStreamAsync(cancellationToken);
+            using var document = await JsonDocument.ParseAsync(stream, cancellationToken: cancellationToken);
+
+            foreach (var element in document.RootElement.GetProperty("items").EnumerateArray())
+            {
+                yield return element.GetProperty("name").GetString();
+            }
+        } while (link is { Next: not null });
+    }
+}

src/AzureAppConfigurationEmulator.Common/Headers/LinkHeaderValue.cs

@@ -0,0 +1,65 @@
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace AzureAppConfigurationEmulator.Common.Headers;
+
+public partial class LinkHeaderValue
+{
+    private readonly IDictionary<string, ICollection<Uri>> _values;
+
+    private LinkHeaderValue(IDictionary<string, ICollection<Uri>> values)
+    {
+        _values = values;
+    }
+
+    public IEnumerable<Uri>? Next => _values.TryGetValue("next", out var uris) ? uris : null;
+
+    public IEnumerable<Uri>? Prev => _values.TryGetValue("prev", out var uris) ? uris : null;
+
+    public static LinkHeaderValue Parse(string input)
+    {
+        var values = new Dictionary<string, ICollection<Uri>>();
+
+        if (!string.IsNullOrEmpty(input))
+        {
+            if (input.Split(',') is { Length: > 0 } links)
+            {
+                foreach (var link in links)
+                {
+                    if (RelRegex().Match(link) is { Success: true } rel &&
+                        UriRegex().Match(link) is { Success: true } uri)
+                    {
+                        if (values.TryGetValue(rel.Value, out var uris))
+                        {
+                            uris.Add(new Uri(uri.Value, UriKind.RelativeOrAbsolute));
+                        }
+                        else
+                        {
+                            values.Add(rel.Value, [new Uri(uri.Value, UriKind.RelativeOrAbsolute)]);
+                        }
+                    }
+                }
+            }
+        }
+
+        return new LinkHeaderValue(values);
+    }
+
+    public override string ToString()
+    {
+        var builder = new StringBuilder();
+
+        foreach (var (rel, uris) in _values)
+        {
+            builder.AppendJoin(", ", uris.Select(uri => $"<{uri}>; rel=\"{rel}\""));
+        }
+
+        return builder.ToString();
+    }
+
+    [GeneratedRegex("(?<=rel=\").+?(?=\")")]
+    private static partial Regex RelRegex();
+
+    [GeneratedRegex("(?<=<).+?(?=>)")]
+    private static partial Regex UriRegex();
+}

src/AzureAppConfigurationEmulator/Components/AzureInputDate.razor

@@ -0,0 +1,14 @@
+@typeparam TValue
+@using System.Linq.Expressions
+
+<InputDate @attributes="@AdditionalAttributes" class="px-2 pt-1 pb-1.5 w-full bg-white rounded-sm border border-storm-dust h-[24px] placeholder:text-storm-dust invalid:border-alizarin-crimson dark:bg-cod-grey dark:border-star-dust dark:placeholder:text-star-dust dark:disabled:bg-shark dark:disabled:border-natural-grey dark:disabled:text-natural-grey disabled:bg-concrete disabled:border-star-dust disabled:text-star-dust" Value="@Value" ValueChanged="@ValueChanged" ValueExpression="@ValueExpression"/>
+
+@code {
+    [Parameter(CaptureUnmatchedValues = true)] public IDictionary<string, object>? AdditionalAttributes { get; set; }
+
+    [Parameter] public TValue? Value { get; set; }
+
+    [Parameter] public EventCallback<TValue?> ValueChanged { get; set; }
+
+    [Parameter] public Expression<Func<TValue?>>? ValueExpression { get; set; }
+}

src/AzureAppConfigurationEmulator/Components/AzureInputRadioGroup.razor

@@ -14,7 +14,7 @@
 
     [Parameter] public TValue? Value { get; set; }
 
-    [Parameter] public EventCallback<TValue> ValueChanged { get; set; }
+    [Parameter] public EventCallback<TValue?> ValueChanged { get; set; }
 
-    [Parameter] public Expression<Func<TValue>>? ValueExpression { get; set; }
+    [Parameter] public Expression<Func<TValue?>>? ValueExpression { get; set; }
 }

src/AzureAppConfigurationEmulator/Components/AzureInputSelect.razor

@@ -1,7 +1,7 @@
 @typeparam TValue
 @using System.Linq.Expressions
 
-<InputSelect @attributes="@AdditionalAttributes" class="px-1 pt-0 pb-0.5 w-full bg-white rounded-sm border cursor-pointer disabled:cursor-default border-storm-dust h-[24px] invalid:border-alizarin-crimson dark:bg-cod-grey dark:border-star-dust dark:disabled:bg-shark dark:disabled:border-natural-grey dark:disabled:text-natural-grey disabled:bg-concrete disabled:border-star-dust disabled:text-star-dust" Value="@Value" ValueChanged="@ValueChanged" ValueExpression="@ValueExpression">
+<InputSelect @attributes="@AdditionalAttributes" class="px-1 pt-0 pb-0.5 w-full bg-white rounded-sm border cursor-pointer disabled:cursor-default border-storm-dust [&:not(multiple)]:h-[24px] invalid:border-alizarin-crimson dark:bg-cod-grey dark:border-star-dust dark:disabled:bg-shark dark:disabled:border-natural-grey dark:disabled:text-natural-grey disabled:bg-concrete disabled:border-star-dust disabled:text-star-dust" Value="@Value" ValueChanged="@ValueChanged" ValueExpression="@ValueExpression">
     @ChildContent
 </InputSelect>
 
@@ -12,7 +12,7 @@
 
     [Parameter] public TValue? Value { get; set; }
 
-    [Parameter] public EventCallback<TValue> ValueChanged { get; set; }
+    [Parameter] public EventCallback<TValue?> ValueChanged { get; set; }
 
-    [Parameter] public Expression<Func<TValue>>? ValueExpression { get; set; }
+    [Parameter] public Expression<Func<TValue?>>? ValueExpression { get; set; }
 }

src/AzureAppConfigurationEmulator/Components/AzureInputText.razor

@@ -4,12 +4,10 @@
 
 @code {
     [Parameter(CaptureUnmatchedValues = true)] public IDictionary<string, object>? AdditionalAttributes { get; set; }
-
-    [Parameter] public RenderFragment? ChildContent { get; set; }
 
     [Parameter] public string? Value { get; set; }
 
-    [Parameter] public EventCallback<string> ValueChanged { get; set; }
+    [Parameter] public EventCallback<string?> ValueChanged { get; set; }
 
-    [Parameter] public Expression<Func<string>>? ValueExpression { get; set; }
+    [Parameter] public Expression<Func<string?>>? ValueExpression { get; set; }
 }

src/AzureAppConfigurationEmulator/Components/ImportExportContentTypeInputSelect.razor

@@ -0,0 +1,24 @@
+@using System.Linq.Expressions
+@using AzureAppConfigurationEmulator.Common.Constants
+
+<AzureInputSelect AdditionalAttributes="@AdditionalAttributes" TValue="@string" Value="@Value" ValueChanged="@HandleValueChanged" ValueExpression="@ValueExpression">
+    <option checked="@(Value is null)" value="">(No content type)</option>
+    <option checked="@(Value is MediaType.SecretReference)" value="@MediaType.SecretReference">Key Vault Reference (@MediaType.SecretReference)</option>
+    <option checked="@(Value is MediaType.Json)" value="@MediaType.Json">JSON (@MediaType.Json)</option>
+</AzureInputSelect>
+
+@code {
+    [Parameter(CaptureUnmatchedValues = true)] public IDictionary<string, object>? AdditionalAttributes { get; set; }
+
+    [Parameter] public string? Value { get; set; }
+
+    [Parameter] public EventCallback<string?> ValueChanged { get; set; }
+
+    [Parameter] public Expression<Func<string?>>? ValueExpression { get; set; }
+
+    private async Task HandleValueChanged(string? value)
+    {
+        await ValueChanged.InvokeAsync(!string.IsNullOrEmpty(value) ? value : null);
+    }
+
+}