using System.Text;
using System.Text.Json.Nodes;
using w4c_workflows.Models.Credentials;
using w4c_workflows.Services.Credentials;
using Xunit;

namespace w4c_workflows.Tests;

/// <summary>
/// The injection strategy turns a resolved credential into request material:
/// Basic/Bearer authorization, a custom header, or a query parameter.
/// </summary>
public class CredentialInjectorTests
{
    private static readonly CredentialTypeCatalog Catalog = new();

    private static HttpRequestMessage Request() => new(HttpMethod.Get, "https://api.example.com/items");

    [Fact]
    public void Basic_sets_the_authorization_header()
    {
        var request = Request();
        var credential = new CredentialData("httpBasicAuth", new JsonObject
        {
            ["username"] = "ada",
            ["password"] = "secret",
        });

        Assert.Null(CredentialInjector.Apply(credential, Catalog, request));

        var expected = "Basic " + Convert.ToBase64String(Encoding.UTF8.GetBytes("ada:secret"));
        Assert.Equal(expected, request.Headers.Authorization!.ToString());
    }

    [Fact]
    public void Bearer_sets_the_authorization_header_with_the_prefix()
    {
        var request = Request();
        var credential = new CredentialData("httpBearerAuth", new JsonObject { ["token"] = "tok-123" });

        Assert.Null(CredentialInjector.Apply(credential, Catalog, request));
        Assert.Equal("Bearer tok-123", request.Headers.Authorization!.ToString());
    }

    [Fact]
    public void Header_adds_a_custom_request_header()
    {
        var request = Request();
        var credential = new CredentialData("httpHeaderAuth", new JsonObject
        {
            ["name"] = "X-API-Key",
            ["value"] = "abc",
        });

        Assert.Null(CredentialInjector.Apply(credential, Catalog, request));
        Assert.Equal("abc", request.Headers.GetValues("X-API-Key").Single());
    }

    [Fact]
    public void Query_appends_a_parameter()
    {
        var request = Request();
        var credential = new CredentialData("httpQueryAuth", new JsonObject
        {
            ["name"] = "api_key",
            ["value"] = "abc",
        });

        Assert.Null(CredentialInjector.Apply(credential, Catalog, request));
        Assert.Contains("api_key=abc", request.RequestUri!.Query);
    }

    [Fact]
    public void A_missing_required_field_is_reported()
    {
        var request = Request();
        var credential = new CredentialData("httpBearerAuth", new JsonObject());

        var error = CredentialInjector.Apply(credential, Catalog, request);

        Assert.NotNull(error);
        Assert.Contains("token", error);
    }

    [Fact]
    public void An_unknown_type_is_reported()
    {
        var request = Request();
        var credential = new CredentialData("nope", new JsonObject());

        Assert.Equal("unknown credential type 'nope'", CredentialInjector.Apply(credential, Catalog, request));
    }

    [Fact]
    public void None_injection_leaves_the_request_untouched()
    {
        var request = Request();
        var credential = new CredentialData("telegramApi", new JsonObject { ["token"] = "123:ABC" });

        Assert.Null(CredentialInjector.Apply(credential, Catalog, request));
        Assert.Equal("https://api.example.com/items", request.RequestUri!.ToString());
        Assert.Null(request.Headers.Authorization);
    }

    [Fact]
    public void Catalog_exposes_the_url_embedded_credential_types()
    {
        var telegram = Catalog.Get("telegramApi");
        var discord = Catalog.Get("discordWebhook");

        Assert.NotNull(telegram);
        Assert.NotNull(discord);
        Assert.Equal(CredentialInjectionKind.None, telegram!.Injection.Kind);
        Assert.Equal(CredentialInjectionKind.None, discord!.Injection.Kind);
        Assert.Contains(telegram.Fields, f => f.Name == "token");
        Assert.Contains(discord.Fields, f => f.Name == "url");
    }
}