using System.Net;
using System.Net.Http.Json;
using Hua.Todo.Application.Common;
using Hua.Todo.Application.Repositories;
using Hua.Todo.Application.Services.CloudSync.Models;
using Hua.Todo.HttpApi.AspNetCore.CloudSync;
using Hua.Todo.HttpApi.AspNetCore.DynamicApi;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Xunit;

namespace Hua.Todo.Host.Tests.CloudSync;

/// <summary>
/// 模式 B（Web 端）根路径托管 Hua.Todo.Web 静态页的验收测试。
///
/// 依据 v1.3.0 工单 06 的 6 条 Given-When-Then：
///   1. 根路径 / 返回 200 + HTML（含 &lt;div id="app"&gt;）
///   2. SPA 内部路由 /settings fallback 到 index.html
///   3. /api/* 动态 API 不被 fallback 覆盖
///   4. /swagger 不被 fallback 覆盖（中间件顺序保证）
///
/// RED 阶段：当前 Program.cs 没有 UseDefaultFiles / UseStaticFiles / MapFallbackToFile，
///          因此根路径断言会失败（404，body 非 HTML）。
/// GREEN 阶段：按工单 06 §五 5.1 的 Program.cs 顺序补齐中间件后，全部通过。
/// </summary>
public sealed class WebRootStaticFileTests : IDisposable
{
    private readonly SqliteConnection _connection;
    private readonly string _webRootDir;
    private readonly HttpClient _client;
    private readonly WebApplication _app;

    /// <summary>
    /// 写入到临时 wwwroot/index.html 的特征字符串，供断言用。
    /// 避免与实际 Hua.Todo.Web 构建耦合（测试不需要真的 npm build）。
    /// </summary>
    private const string SpaMountPoint = "<div id=\"app\">SpaMount</div>";
    private const string SpaTitle = "<title>Hua.Todo - ServedByHost</title>";

    public WebRootStaticFileTests()
    {
        // === 将临时 wwwroot/index.html 写入默认 WebRoot（无需改 WebRoot，避免 WebApplicationBuilder.WebHost.UseWebRoot 抛 NotSupportedException）===
        // WebApplicationBuilder 启动后默认 WebRoot = AppContext.BaseDirectory/wwwroot（即 bin/Debug/net10.0/wwwroot）
        var baseDir = AppContext.BaseDirectory;
        _webRootDir = Path.Combine(baseDir, "wwwroot");
        Directory.CreateDirectory(_webRootDir);
        File.WriteAllText(
            Path.Combine(_webRootDir, "index.html"),
            $"<!doctype html><html><head>{SpaTitle}</head><body>{SpaMountPoint}</body></html>");

        // === 内存 SQLite（与既有集成测试同模式） ===
        _connection = new SqliteConnection("Data Source=WebRootStaticFileTests;Mode=Memory;Cache=Shared");
        _connection.Open();

        _app = BuildHost(environmentName: "Development");
        _client = new HttpClient(new HttpClientHandler { AllowAutoRedirect = false })
        {
            BaseAddress = new Uri(_app.Urls.First()),
        };
    }

    private WebApplication BuildHost(string environmentName)
    {
        var builder = WebApplication.CreateBuilder();
        builder.Environment.EnvironmentName = environmentName;
        builder.WebHost.UseUrls("http://127.0.0.1:0");

        builder.Services.AddEndpointsApiExplorer();
        builder.Services.AddSwaggerGen();

        builder.Services.AddApplicationServices("Data Source=WebRootStaticFileTests;Mode=Memory;Cache=Shared");
        builder.Services.AddDbContext<TodoDbContext>(options => options.UseSqlite(_connection));
        builder.Services.AddCloudSyncServer();

        var app = builder.Build();

        using (var scope = app.Services.CreateScope())
        {
            var db = scope.ServiceProvider.GetRequiredService<TodoDbContext>();
            db.Database.EnsureCreated();
        }

        if (app.Environment.IsDevelopment())
        {
            app.UseSwagger();
            app.UseSwaggerUI();
        }

        // === GREEN：按 Program.cs 硬约束顺序启用静态文件中间件 + SPA fallback ===
        app.UseDefaultFiles();
        app.UseStaticFiles();

        app.UseAuthentication();
        app.UseAuthorization();
        app.UseDynamicApi();

        // SPA fallback（在 UseDynamicApi 之后，不覆盖 /api/*）
        app.MapFallbackToFile("index.html");

        app.StartAsync().GetAwaiter().GetResult();
        return app;
    }

    [Fact]
    public async Task Root_Get_ReturnsIndexHtml_WithAppMountDiv()
    {
        // Given: Host 启动且 WebRoot/wwwroot 有 index.html
        // When : HTTP GET /
        // Then : 200 + text/html + body 含 <div id="app"> 挂载点
        using var response = await _client.GetAsync("/");

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

        var body = await response.Content.ReadAsStringAsync();
        Assert.Contains(SpaMountPoint, body, StringComparison.Ordinal);
        Assert.Contains(SpaTitle, body, StringComparison.Ordinal);
    }

    [Fact]
    public async Task SpaRoute_Settings_Get_FallsBackToIndexHtml_Not404()
    {
        // Given: 同上
        // When : HTTP GET /settings（前端内部路由）
        // Then : 200 + body 是 index.html（注意：404 是 RED 时的现状，也是本测试在 RED 阶段失败的原因）
        using var response = await _client.GetAsync("/settings");

        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
        var body = await response.Content.ReadAsStringAsync();
        Assert.Contains(SpaMountPoint, body, StringComparison.Ordinal);
    }

    [Fact]
    public async Task ApiDynamicApiRoute_PostProbe_NotOverriddenByFallback()
    {
        // Given: 同上
        // When : HTTP POST /api/cloud-sync/probe（匿名 DynamicApi 端点）
        // Then : 返回 JSON（body 含 isReachable 字段），不是 index.html
        //        不要求 isReachable=true，因为 test 里 Host 没监听 5173，必 false；也可能 503，但不是 HTML。
        using var response = await _client.PostAsJsonAsync("/api/cloud-sync/probe",
            new ProbeRequest { TargetUrl = "http://localhost:5173" });

        // 状态码不是 404 / 不返回 fallback 的 HTML：
        Assert.NotEqual(HttpStatusCode.NotFound, response.StatusCode);
        var body = await response.Content.ReadAsStringAsync();
        Assert.DoesNotContain(SpaMountPoint, body, StringComparison.Ordinal);

        // 至少含 DynamicApi 的 JSON 特征：isReachable 字段
        Assert.Contains("isReachable", body, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public async Task SwaggerUi_Get_Returns200_NotOverriddenByFallback()
    {
        // Given: 开发环境，Swagger 启用
        // When : HTTP GET /swagger/index.html
        // Then : 200，body 含 Swagger UI 的 "Swagger UI" 或 "swagger-ui"，不是前端 index.html
        using var response = await _client.GetAsync("/swagger/index.html");

        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
        var body = await response.Content.ReadAsStringAsync();
        Assert.Contains("swagger", body, StringComparison.OrdinalIgnoreCase);
        Assert.DoesNotContain(SpaMountPoint, body, StringComparison.Ordinal);
    }

    public void Dispose()
    {
        _client.Dispose();

        try { _app.StopAsync().GetAwaiter().GetResult(); } catch { /* 忽略 */ }
        try { _app.DisposeAsync().GetAwaiter().GetResult(); } catch { /* 忽略 */ }

        _connection.Dispose();
        // 清理临时写入的 index.html（只删我们自己写的，不删目录里的其他可能文件）
        try
        {
            var idx = Path.Combine(_webRootDir, "index.html");
            if (File.Exists(idx)) File.Delete(idx);
        }
        catch { /* 忽略临时文件清理失败 */ }
    }
}