using System.Net;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.Extensions.Configuration;

namespace Flyshot.Server.IntegrationTests;

/// <summary>
/// 验证 `/debug` 在线 API 调试页的暴露策略与基础内容契约。
/// </summary>
/// <remarks>
/// 调试页与 Swagger UI 共用 <c>Swagger:Enabled</c> 开关，开关关闭时
/// 调试页与 `/swagger` 一同下线，避免生产环境意外暴露调试入口。
/// </remarks>
public sealed class DebugConsoleEndpointTests(FlyshotServerFactory factory) : IClassFixture<FlyshotServerFactory>
{
    private readonly FlyshotServerFactory _factory = factory;

    /// <summary>
    /// 当 Swagger 启用时，`/debug` 应当返回完整的 HTML 调试页。
    /// </summary>
    [Fact]
    public async Task GetDebug_WhenSwaggerEnabled_ReturnsConsoleHtml()
    {
        // 默认配置即开启 Swagger，调试页应当作为浏览器可直接打开的 HTML 暴露。
        using var configuredFactory = CreateFactoryWithSwaggerEnabled(true);
        using var client = configuredFactory.CreateClient();

        using var response = await client.GetAsync("/debug");

        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
        Assert.StartsWith("text/html", response.Content.Headers.ContentType?.MediaType);

        var html = await response.Content.ReadAsStringAsync();

        // 页面标题与稳定锚点用于回归保护：调试页骨架一旦丢失，测试立即报警。
        Assert.Contains("Flyshot Replacement 接口调试", html, StringComparison.Ordinal);
        Assert.Contains("id=\"debug-console-app\"", html, StringComparison.Ordinal);

        // 控制器需要在返回 HTML 前把 Swagger JSON URL 注入到页面占位符里，
        // 否则前端无法在加载时拉取 OpenAPI 文档。
        Assert.Contains("/swagger/v1/swagger.json", html, StringComparison.Ordinal);
        Assert.DoesNotContain("__SWAGGER_JSON_URL__", html, StringComparison.Ordinal);
    }

    /// <summary>
    /// 当 Swagger 关闭时，`/debug` 应当与 `/swagger` 同步下线（404）。
    /// </summary>
    [Fact]
    public async Task GetDebug_WhenSwaggerDisabled_ReturnsNotFound()
    {
        // 显式把 Swagger:Enabled 置为 false，此时调试页也不应当被访问到。
        using var configuredFactory = CreateFactoryWithSwaggerEnabled(false);
        using var client = configuredFactory.CreateClient();

        using var response = await client.GetAsync("/debug");

        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
    }

    /// <summary>
    /// 调试页需要从 Swagger JSON 中读取所有端点，因此 Swagger 文档必须包含基础和兼容层的代表性路由。
    /// </summary>
    [Fact]
    public async Task SwaggerDocument_ContainsRepresentativeRoutesForDebugConsole()
    {
        using var configuredFactory = CreateFactoryWithSwaggerEnabled(true);
        using var client = configuredFactory.CreateClient();

        using var response = await client.GetAsync("/swagger/v1/swagger.json");
        Assert.Equal(HttpStatusCode.OK, response.StatusCode);

        await using var responseStream = await response.Content.ReadAsStreamAsync();
        using var document = await System.Text.Json.JsonDocument.ParseAsync(responseStream);
        var paths = document.RootElement.GetProperty("paths");

        // 这些路径分别覆盖：基础探活、状态快照、版本查询、上传飞拍轨迹四种典型形态。
        AssertPathExists(paths, "/healthz");
        AssertPathExists(paths, "/api/status/snapshot");
        AssertPathExists(paths, "/get_server_version");
        AssertPathExists(paths, "/upload_flyshot");
    }

    /// <summary>
    /// 状态页应当提供跳转到调试页的入口，便于现场顺手跳转。
    /// </summary>
    [Fact]
    public async Task GetStatusPage_LinksToDebugConsole()
    {
        using var configuredFactory = CreateFactoryWithSwaggerEnabled(true);
        using var client = configuredFactory.CreateClient();

        using var response = await client.GetAsync("/status");

        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
        var html = await response.Content.ReadAsStringAsync();

        // 状态页头部需要至少一个指向 `/debug` 的链接，文案不强制以保留排版调整空间。
        Assert.Contains("href=\"/debug\"", html, StringComparison.Ordinal);
    }

    /// <summary>
    /// 检查 Swagger 文档中是否存在指定路径，兼容尾斜杠归一化两种形态。
    /// </summary>
    /// <param name="paths">OpenAPI 文档中的 paths 节点。</param>
    /// <param name="route">期望存在的路由字符串。</param>
    private static void AssertPathExists(System.Text.Json.JsonElement paths, string route)
    {
        // OpenAPI 生成器会把部分尾斜杠路径规范化，这里同时接受两种形态。
        var withSlash = route.EndsWith('/') ? route : route + "/";
        var withoutSlash = route.EndsWith('/') ? route.TrimEnd('/') : route;

        Assert.True(
            paths.TryGetProperty(withSlash, out _) || paths.TryGetProperty(withoutSlash, out _),
            $"Swagger 文档应当包含路径 {route}");
    }

    /// <summary>
    /// 构造覆盖了 <c>Swagger:Enabled</c> 配置项的测试宿主工厂。
    /// </summary>
    /// <param name="enabled">期望的 Swagger 启用状态。</param>
    /// <returns>已应用配置覆盖的测试工厂。</returns>
    private WebApplicationFactory<Program> CreateFactoryWithSwaggerEnabled(bool enabled)
    {
        return _factory.WithWebHostBuilder(builder =>
        {
            builder.ConfigureAppConfiguration((_, configurationBuilder) =>
            {
                // 通过 InMemory 配置覆盖 appsettings.json 中的 Swagger 开关，避免修改磁盘文件。
                configurationBuilder.AddInMemoryCollection(new Dictionary<string, string?>
                {
                    ["Swagger:Enabled"] = enabled ? "true" : "false",
                    ["Swagger:DocumentName"] = "v1",
                    ["Swagger:Title"] = "Flyshot Replacement HTTP API",
                    ["Swagger:Version"] = "v1",
                    ["Swagger:JsonRouteTemplate"] = "swagger/{documentName}/swagger.json",
                    ["Swagger:RoutePrefix"] = "swagger"
                });
            });
        });
    }
}