using FluentAssertions;
using StellaOps.Router.Common.Enums;
using StellaOps.Router.Common.Models;
using StellaOps.Router.Gateway.State;
using Xunit;

namespace StellaOps.Router.Gateway.Tests;

public sealed class InMemoryRoutingStateTests
{
    [Fact]
    public void ResolveEndpoint_WhenExactMatch_ReturnsEndpointDescriptor()
    {
        var routingState = new InMemoryRoutingState();

        var connection = CreateConnection("conn-1", "inventory", "1.0.0", region: "test");
        connection.Endpoints[("GET", "/items")] = new EndpointDescriptor
        {
            ServiceName = "inventory",
            Version = "1.0.0",
            Method = "GET",
            Path = "/items"
        };

        routingState.AddConnection(connection);

        var resolved = routingState.ResolveEndpoint("GET", "/items");

        resolved.Should().NotBeNull();
        resolved!.ServiceName.Should().Be("inventory");
        resolved.Version.Should().Be("1.0.0");
        resolved.Method.Should().Be("GET");
        resolved.Path.Should().Be("/items");
    }

    [Fact]
    public void ResolveEndpoint_WhenTemplateMatch_ReturnsEndpointDescriptor()
    {
        var routingState = new InMemoryRoutingState();

        var connection = CreateConnection("conn-1", "inventory", "1.0.0", region: "test");
        connection.Endpoints[("GET", "/items/{sku}")] = new EndpointDescriptor
        {
            ServiceName = "inventory",
            Version = "1.0.0",
            Method = "GET",
            Path = "/items/{sku}"
        };

        routingState.AddConnection(connection);

        var resolved = routingState.ResolveEndpoint("GET", "/items/SKU-001");

        resolved.Should().NotBeNull();
        resolved!.Path.Should().Be("/items/{sku}");
    }

    [Fact]
    public void RemoveConnection_RemovesEndpointsFromIndex()
    {
        var routingState = new InMemoryRoutingState();

        var connection = CreateConnection("conn-1", "inventory", "1.0.0", region: "test");
        connection.Endpoints[("GET", "/items")] = new EndpointDescriptor
        {
            ServiceName = "inventory",
            Version = "1.0.0",
            Method = "GET",
            Path = "/items"
        };

        routingState.AddConnection(connection);
        routingState.ResolveEndpoint("GET", "/items").Should().NotBeNull();

        routingState.RemoveConnection("conn-1");

        routingState.ResolveEndpoint("GET", "/items").Should().BeNull();
        routingState.GetAllConnections().Should().BeEmpty();
    }

    [Fact]
    public void GetConnectionsFor_FiltersByServiceAndVersion()
    {
        var routingState = new InMemoryRoutingState();

        var inventoryV1 = CreateConnection("inv-v1", "inventory", "1.0.0", region: "test");
        inventoryV1.Endpoints[("GET", "/items")] = new EndpointDescriptor
        {
            ServiceName = "inventory",
            Version = "1.0.0",
            Method = "GET",
            Path = "/items"
        };

        var inventoryV2 = CreateConnection("inv-v2", "inventory", "2.0.0", region: "test");
        inventoryV2.Endpoints[("GET", "/items")] = new EndpointDescriptor
        {
            ServiceName = "inventory",
            Version = "2.0.0",
            Method = "GET",
            Path = "/items"
        };

        routingState.AddConnection(inventoryV1);
        routingState.AddConnection(inventoryV2);

        var connections = routingState.GetConnectionsFor(
            serviceName: "inventory",
            version: "1.0.0",
            method: "GET",
            path: "/items");

        connections.Should().HaveCount(1);
        connections[0].ConnectionId.Should().Be("inv-v1");
    }

    private static ConnectionState CreateConnection(
        string connectionId,
        string serviceName,
        string version,
        string region)
    {
        return new ConnectionState
        {
            ConnectionId = connectionId,
            Instance = new InstanceDescriptor
            {
                InstanceId = connectionId,
                ServiceName = serviceName,
                Version = version,
                Region = region
            },
            Status = InstanceHealthStatus.Healthy,
            LastHeartbeatUtc = DateTime.UtcNow,
            TransportType = TransportType.InMemory
        };
    }
}