namespace StellaOps.Router.Common.Tests;

/// <summary>
/// Unit tests for <see cref="PathMatcher"/>.
/// </summary>
public sealed class PathMatcherTests
{
    #region Constructor Tests

    [Fact]
    public void Constructor_SetsTemplate()
    {
        // Arrange & Act
        var matcher = new PathMatcher("/api/users/{id}");

        // Assert
        matcher.Template.Should().Be("/api/users/{id}");
    }

    [Fact]
    public void Constructor_DefaultsCaseInsensitive()
    {
        // Arrange & Act
        var matcher = new PathMatcher("/api/Users");

        // Assert
        matcher.IsMatch("/api/users").Should().BeTrue();
    }

    [Fact]
    public void Constructor_CaseSensitive_DoesNotMatchDifferentCase()
    {
        // Arrange & Act
        var matcher = new PathMatcher("/api/Users", caseInsensitive: false);

        // Assert
        matcher.IsMatch("/api/users").Should().BeFalse();
        matcher.IsMatch("/api/Users").Should().BeTrue();
    }

    #endregion

    #region IsMatch Tests - Exact Paths

    [Fact]
    public void IsMatch_ExactPath_ReturnsTrue()
    {
        // Arrange
        var matcher = new PathMatcher("/api/health");

        // Act & Assert
        matcher.IsMatch("/api/health").Should().BeTrue();
    }

    [Fact]
    public void IsMatch_ExactPath_TrailingSlash_ReturnsTrue()
    {
        // Arrange
        var matcher = new PathMatcher("/api/health");

        // Act & Assert
        matcher.IsMatch("/api/health/").Should().BeTrue();
    }

    [Fact]
    public void IsMatch_ExactPath_NoLeadingSlash_ReturnsTrue()
    {
        // Arrange
        var matcher = new PathMatcher("/api/health");

        // Act & Assert
        matcher.IsMatch("api/health").Should().BeTrue();
    }

    [Fact]
    public void IsMatch_DifferentPath_ReturnsFalse()
    {
        // Arrange
        var matcher = new PathMatcher("/api/health");

        // Act & Assert
        matcher.IsMatch("/api/status").Should().BeFalse();
    }

    [Fact]
    public void IsMatch_PartialPath_ReturnsFalse()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/list");

        // Act & Assert
        matcher.IsMatch("/api/users").Should().BeFalse();
    }

    [Fact]
    public void IsMatch_LongerPath_ReturnsFalse()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users");

        // Act & Assert
        matcher.IsMatch("/api/users/list").Should().BeFalse();
    }

    #endregion

    #region IsMatch Tests - Case Sensitivity

    [Fact]
    public void IsMatch_CaseInsensitive_MatchesMixedCase()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users", caseInsensitive: true);

        // Act & Assert
        matcher.IsMatch("/API/USERS").Should().BeTrue();
        matcher.IsMatch("/Api/Users").Should().BeTrue();
        matcher.IsMatch("/aPi/uSeRs").Should().BeTrue();
    }

    [Fact]
    public void IsMatch_CaseSensitive_OnlyMatchesExactCase()
    {
        // Arrange
        var matcher = new PathMatcher("/Api/Users", caseInsensitive: false);

        // Act & Assert
        matcher.IsMatch("/Api/Users").Should().BeTrue();
        matcher.IsMatch("/api/users").Should().BeFalse();
        matcher.IsMatch("/API/USERS").Should().BeFalse();
    }

    #endregion

    #region TryMatch Tests - Single Parameter

    [Fact]
    public void TryMatch_SingleParameter_ReturnsTrue()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{id}");

        // Act
        var result = matcher.TryMatch("/api/users/123", out var parameters);

        // Assert
        result.Should().BeTrue();
    }

    [Fact]
    public void TryMatch_SingleParameter_ExtractsParameter()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{id}");

        // Act
        matcher.TryMatch("/api/users/123", out var parameters);

        // Assert
        parameters.Should().ContainKey("id");
        parameters["id"].Should().Be("123");
    }

    [Fact]
    public void TryMatch_SingleParameter_ExtractsGuidParameter()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{userId}");
        var guid = Guid.NewGuid().ToString();

        // Act
        matcher.TryMatch($"/api/users/{guid}", out var parameters);

        // Assert
        parameters["userId"].Should().Be(guid);
    }

    [Fact]
    public void TryMatch_SingleParameter_ExtractsStringParameter()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{username}");

        // Act
        matcher.TryMatch("/api/users/john-doe", out var parameters);

        // Assert
        parameters["username"].Should().Be("john-doe");
    }

    #endregion

    #region TryMatch Tests - Multiple Parameters

    [Fact]
    public void TryMatch_MultipleParameters_ReturnsTrue()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{userId}/posts/{postId}");

        // Act
        var result = matcher.TryMatch("/api/users/123/posts/456", out _);

        // Assert
        result.Should().BeTrue();
    }

    [Fact]
    public void TryMatch_MultipleParameters_ExtractsAllParameters()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{userId}/posts/{postId}");

        // Act
        matcher.TryMatch("/api/users/user-1/posts/post-2", out var parameters);

        // Assert
        parameters.Should().ContainKey("userId");
        parameters.Should().ContainKey("postId");
        parameters["userId"].Should().Be("user-1");
        parameters["postId"].Should().Be("post-2");
    }

    [Fact]
    public void TryMatch_ThreeParameters_ExtractsAllParameters()
    {
        // Arrange
        var matcher = new PathMatcher("/api/org/{orgId}/users/{userId}/roles/{roleId}");

        // Act
        matcher.TryMatch("/api/org/acme/users/john/roles/admin", out var parameters);

        // Assert
        parameters.Should().HaveCount(3);
        parameters["orgId"].Should().Be("acme");
        parameters["userId"].Should().Be("john");
        parameters["roleId"].Should().Be("admin");
    }

    #endregion

    #region TryMatch Tests - Non-Matching

    [Fact]
    public void TryMatch_NonMatchingPath_ReturnsFalse()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{id}");

        // Act
        var result = matcher.TryMatch("/api/posts/123", out var parameters);

        // Assert
        result.Should().BeFalse();
        parameters.Should().BeEmpty();
    }

    [Fact]
    public void TryMatch_MissingParameter_ReturnsFalse()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{id}/posts/{postId}");

        // Act
        var result = matcher.TryMatch("/api/users/123/posts", out var parameters);

        // Assert
        result.Should().BeFalse();
    }

    [Fact]
    public void TryMatch_ExtraSegment_ReturnsFalse()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{id}");

        // Act
        var result = matcher.TryMatch("/api/users/123/extra", out _);

        // Assert
        result.Should().BeFalse();
    }

    #endregion

    #region TryMatch Tests - Path Normalization

    [Fact]
    public void TryMatch_TrailingSlash_Matches()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{id}");

        // Act
        var result = matcher.TryMatch("/api/users/123/", out var parameters);

        // Assert
        result.Should().BeTrue();
        parameters["id"].Should().Be("123");
    }

    [Fact]
    public void TryMatch_NoLeadingSlash_Matches()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{id}");

        // Act
        var result = matcher.TryMatch("api/users/123", out var parameters);

        // Assert
        result.Should().BeTrue();
        parameters["id"].Should().Be("123");
    }

    #endregion

    #region TryMatch Tests - Parameter Type Constraints

    [Fact]
    public void TryMatch_ParameterWithTypeConstraint_ExtractsParameterName()
    {
        // Arrange
        // The PathMatcher ignores type constraints but still extracts the parameter
        var matcher = new PathMatcher("/api/users/{id:int}");

        // Act
        matcher.TryMatch("/api/users/123", out var parameters);

        // Assert
        parameters.Should().ContainKey("id");
        parameters["id"].Should().Be("123");
    }

    [Fact]
    public void TryMatch_ParameterWithGuidConstraint_ExtractsParameterName()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{id:guid}");

        // Act
        matcher.TryMatch("/api/users/abc-123", out var parameters);

        // Assert
        parameters.Should().ContainKey("id");
        parameters["id"].Should().Be("abc-123");
    }

    #endregion

    #region Edge Cases

    [Fact]
    public void TryMatch_RootPath_Matches()
    {
        // Arrange
        var matcher = new PathMatcher("/");

        // Act
        var result = matcher.TryMatch("/", out var parameters);

        // Assert
        result.Should().BeTrue();
        parameters.Should().BeEmpty();
    }

    [Fact]
    public void TryMatch_SingleSegmentWithParameter_Matches()
    {
        // Arrange
        var matcher = new PathMatcher("/{id}");

        // Act
        var result = matcher.TryMatch("/test-value", out var parameters);

        // Assert
        result.Should().BeTrue();
        parameters["id"].Should().Be("test-value");
    }

    [Fact]
    public void IsMatch_EmptyPath_HandlesGracefully()
    {
        // Arrange
        var matcher = new PathMatcher("/");

        // Act
        var result = matcher.IsMatch("");

        // Assert
        result.Should().BeTrue();
    }

    [Fact]
    public void TryMatch_ParameterWithHyphen_Extracts()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{user-id}");

        // Act
        matcher.TryMatch("/api/users/123", out var parameters);

        // Assert
        parameters.Should().ContainKey("user-id");
        parameters["user-id"].Should().Be("123");
    }

    [Fact]
    public void TryMatch_ParameterWithUnderscore_Extracts()
    {
        // Arrange
        var matcher = new PathMatcher("/api/users/{user_id}");

        // Act
        matcher.TryMatch("/api/users/456", out var parameters);

        // Assert
        parameters.Should().ContainKey("user_id");
    }

    [Fact]
    public void TryMatch_SpecialCharactersInPath_Matches()
    {
        // Arrange
        var matcher = new PathMatcher("/api/search/{query}");

        // Act
        matcher.TryMatch("/api/search/hello-world_test.123", out var parameters);

        // Assert
        parameters["query"].Should().Be("hello-world_test.123");
    }

    [Fact]
    public void IsMatch_ComplexRealWorldPath_Matches()
    {
        // Arrange
        var matcher = new PathMatcher("/v1/organizations/{orgId}/projects/{projectId}/scans/{scanId}/vulnerabilities");

        // Act
        var result = matcher.IsMatch("/v1/organizations/acme-corp/projects/webapp/scans/scan-2024-001/vulnerabilities");

        // Assert
        result.Should().BeTrue();
    }

    [Fact]
    public void TryMatch_ComplexRealWorldPath_ExtractsAllParameters()
    {
        // Arrange
        var matcher = new PathMatcher("/v1/organizations/{orgId}/projects/{projectId}/scans/{scanId}");

        // Act
        matcher.TryMatch("/v1/organizations/acme-corp/projects/webapp/scans/scan-2024-001", out var parameters);

        // Assert
        parameters["orgId"].Should().Be("acme-corp");
        parameters["projectId"].Should().Be("webapp");
        parameters["scanId"].Should().Be("scan-2024-001");
    }

    #endregion
}