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

namespace w4c_workflows.Tests;

/// <summary>
/// The extraction strategy reads an OAuth-style token response, including
/// non-standard token locations (e.g. Slack's <c>authed_user.access_token</c>).
/// </summary>
public class CredentialExtractorTests
{
    private static readonly CredentialExtraction Extraction = new()
    {
        AccessTokenField = "authed_user.access_token",
        TokenTypeField = "token_type",
        ExpiresInField = "expires_in",
        RefreshTokenField = "refresh_token",
        ScopeField = "scope",
        DefaultTokenType = "Bearer",
    };

    [Fact]
    public void Reads_a_nested_access_token_and_the_standard_fields()
    {
        var response = JsonNode.Parse("""
            {
              "ok": true,
              "authed_user": { "access_token": "xoxp-123" },
              "token_type": "bearer",
              "expires_in": 3600,
              "refresh_token": "refresh-1",
              "scope": "chat:write"
            }
            """)!.AsObject();

        var tokens = CredentialExtractor.Extract(response, Extraction);

        Assert.NotNull(tokens);
        Assert.Equal("xoxp-123", tokens!.AccessToken);
        Assert.Equal("bearer", tokens.TokenType);
        Assert.Equal(3600, tokens.ExpiresInSeconds);
        Assert.Equal("refresh-1", tokens.RefreshToken);
        Assert.Equal("chat:write", tokens.Scope);
    }

    [Fact]
    public void Falls_back_to_the_default_token_type()
    {
        var response = new JsonObject { ["access_token"] = "tok" };
        var extraction = new CredentialExtraction { AccessTokenField = "access_token", DefaultTokenType = "Bearer" };

        var tokens = CredentialExtractor.Extract(response, extraction);

        Assert.Equal("Bearer", tokens!.TokenType);
        Assert.Null(tokens.ExpiresInSeconds);
    }

    [Fact]
    public void A_response_without_a_token_returns_null()
    {
        var response = new JsonObject { ["error"] = "invalid_grant" };
        Assert.Null(CredentialExtractor.Extract(response, Extraction));
    }
}