using System.Linq;
using System.Text.Json;
using Xunit;

namespace Yh.Platform.AppAuth.Tests;

/// <summary>
/// AppSignHandler basePath 剥离对拍（验收 P1 修复）：
/// 链路 handler(fullUrl) → 剥离 basePath → SignUtil(剥离后 canonicalTarget) → 向量基线（Java 口径）。
/// 证明：经 handler 发出的签名 = Java 客户端对同一 URL 的签名（同 ts 时逐字节一致）。
/// </summary>
public class AppSignHandlerTests
{
    private sealed class CaptureHandler : HttpMessageHandler
    {
        public HttpRequestMessage? Last { get; private set; }

        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken ct)
        {
            Last = request;
            return Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK));
        }
    }

    private const string AppKey = "100476";
    private const string Secret = "app-secret-100476-yunhai";

    private static async Task<HttpRequestMessage> SendThroughHandlerAsync(AppSignHandler handler, HttpMethod method, string url)
    {
        using var client = new HttpClient(handler);
        var request = new HttpRequestMessage(method, url);
        await client.SendAsync(request);
        // handler 已把三头写入同一个 request 实例；CaptureHandler 捕获的是该实例
        return request;
    }

    /// <summary>读取请求级向量：固定 ts 后，经 handler 对 fullUrl 的签名须与向量基线（Java 口径）逐字节一致。</summary>
    public static IEnumerable<object[]> RequestLevelCases()
    {
        var path = Path.Combine(AppContext.BaseDirectory, "fixtures", "sign-vectors.json");
        var root = JsonDocument.Parse(File.ReadAllText(path)).RootElement;
        foreach (var c in root.GetProperty("cases").EnumerateArray())
        {
            if (c.TryGetProperty("fullUrl", out _))
            {
                yield return new object[] { c.Clone() };
            }
        }
    }

    [Theory]
    [MemberData(nameof(RequestLevelCases))]
    public async Task Handler对fullUrl签名_与Java基线逐字节一致(JsonElement c)
    {
        var name = c.GetProperty("name").GetString();
        var method = new HttpMethod(c.GetProperty("method").GetString()!);
        var fullUrl = c.GetProperty("fullUrl").GetString()!;
        var basePath = c.GetProperty("basePath").GetString()!;
        var ts = c.GetProperty("ts").GetString()!;
        var secret = c.GetProperty("secret").GetString()!;
        var expected = c.GetProperty("expectedRequestSignBase64").GetString()!;

        // 固定 ts = 向量 ts（SignUtil.NowMillis 为 handler 与 SignUtil 共用的时钟源）
        var original = SignUtil.NowMillis;
        SignUtil.NowMillis = () => long.Parse(ts);
        try
        {
            var handler = new AppSignHandler(AppKey, secret, basePath, new CaptureHandler());
            var sent = await SendThroughHandlerAsync(handler, method, fullUrl);

            Assert.Equal(AppKey, sent.Headers.GetValues(AppSignHandler.HeaderAppKey).First());
            Assert.Equal(ts, sent.Headers.GetValues(AppSignHandler.HeaderTimestamp).First());
            // 同 URL、同 ts 下与 Java 客户端（AppSignInterceptor 剥 basePath 后）签名逐字节一致
            Assert.Equal(expected, sent.Headers.GetValues(AppSignHandler.HeaderSignature).First());
        }
        finally
        {
            SignUtil.NowMillis = original;
        }
    }

    [Fact]
    public async Task Handler剥离basePath_并排序query后签名()
    {
        var handler = new AppSignHandler(AppKey, Secret, "/userbase", new CaptureHandler());
        var sent = await SendThroughHandlerAsync(handler, HttpMethod.Get,
            "http://base.bestsch.com/userbase/oapi/user/byId?b=2&a=1");

        var ts = sent.Headers.GetValues(AppSignHandler.HeaderTimestamp).First();
        var signature = sent.Headers.GetValues(AppSignHandler.HeaderSignature).First();

        // 剥离 /userbase + query 排序：canonical = /oapi/user/byId?a=1&b=2
        Assert.Equal(SignUtil.SignRequest("GET", "/oapi/user/byId?a=1&b=2", ts, Secret), signature);
    }

    [Fact]
    public async Task Handler未配置basePath_不剥离原样签名()
    {
        var handler = new AppSignHandler(AppKey, Secret, null, new CaptureHandler());
        var sent = await SendThroughHandlerAsync(handler, HttpMethod.Get,
            "http://base.bestsch.com/userbase/oapi/user/byId");

        var ts = sent.Headers.GetValues(AppSignHandler.HeaderTimestamp).First();
        var signature = sent.Headers.GetValues(AppSignHandler.HeaderSignature).First();

        Assert.Equal(SignUtil.SignRequest("GET", "/userbase/oapi/user/byId", ts, Secret), signature);
    }

    [Theory]
    [InlineData("/userbase/oapi/u", "/userbase", "/oapi/u")]
    [InlineData("/userbase", "/userbase", "/")]
    [InlineData("/userbase/", "/userbase", "/")]
    [InlineData("/userbase/oapi/u", "/userbase/", "/oapi/u")]   // basePath 带尾斜杠归一化
    [InlineData("/userbase2/x", "/userbase", "/userbase2/x")]   // 前缀不完整匹配不剥离（对齐 Java）
    [InlineData("/oapi/u", "/userbase", "/oapi/u")]             // 无前缀不剥离
    [InlineData("/userbase/oapi/u", null, "/userbase/oapi/u")]  // basePath 空 = 挂根路径
    public void StripBasePath_边界与Java一致(string path, string? basePath, string expected)
    {
        Assert.Equal(expected, SignCanonical.StripBasePath(path, basePath));
    }

    [Fact]
    public void BuildTarget_带basePath_剥离并排序query()
    {
        Assert.Equal("/oapi/user/byId?a=1&b=2",
            SignCanonical.BuildTarget(new Uri("http://h/userbase/oapi/user/byId?b=2&a=1"), "/userbase"));
        // 不传 basePath 保持既有行为（不剥离，query 仍排序）
        Assert.Equal("/userbase/oapi/user/byId?a=1&b=2",
            SignCanonical.BuildTarget(new Uri("http://h/userbase/oapi/user/byId?b=2&a=1")));
    }
}