using System.Text;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;

namespace YD_Event.Web.Entry.Controllers;

/// <summary>
/// 官网赛事信息管理。使用后台登录态访问，将请求转发到内部赛事服务。
/// </summary>
[ApiController]
[Authorize]
[Route("api/website-competition")]
public sealed class WebsiteCompetitionController : ControllerBase
{
    private readonly IConfiguration _configuration;
    private readonly IHttpClientFactory _httpClientFactory;

    public WebsiteCompetitionController(IConfiguration configuration, IHttpClientFactory httpClientFactory)
    {
        _configuration = configuration;
        _httpClientFactory = httpClientFactory;
    }

    [HttpGet]
    public Task<IActionResult> Get() => ForwardAsync(HttpMethod.Get);

    [HttpPut]
    [RequestSizeLimit(8 * 1024 * 1024)]
    public Task<IActionResult> Put() => ForwardAsync(HttpMethod.Put);

    private async Task<IActionResult> ForwardAsync(HttpMethod method)
    {
        var adminUrl = _configuration["CompetitionApi:AdminUrl"]
            ?? "http://127.0.0.1:8787/api/competition/admin";
        if (!Uri.TryCreate(adminUrl, UriKind.Absolute, out var target)
            || (target.Scheme != Uri.UriSchemeHttp && target.Scheme != Uri.UriSchemeHttps))
            return StatusCode(503, new { error = "官网赛事接口地址无效" });

        using var upstreamRequest = new HttpRequestMessage(method, target);
        if (method == HttpMethod.Put)
        {
            using var reader = new StreamReader(Request.Body, Encoding.UTF8, leaveOpen: true);
            var body = await reader.ReadToEndAsync(HttpContext.RequestAborted);
            upstreamRequest.Content = new StringContent(body, Encoding.UTF8, "application/json");
        }

        try
        {
            var client = _httpClientFactory.CreateClient("WebsiteCompetition");
            client.Timeout = TimeSpan.FromSeconds(30);
            using var upstreamResponse = await client.SendAsync(
                upstreamRequest, HttpCompletionOption.ResponseHeadersRead, HttpContext.RequestAborted);
            var response = await upstreamResponse.Content.ReadAsStringAsync(HttpContext.RequestAborted);
            return new ContentResult
            {
                Content = response,
                ContentType = "application/json; charset=utf-8",
                StatusCode = (int)upstreamResponse.StatusCode
            };
        }
        catch (HttpRequestException)
        {
            return StatusCode(502, new { error = "官网赛事接口连接失败" });
        }
        catch (TaskCanceledException) when (!HttpContext.RequestAborted.IsCancellationRequested)
        {
            return StatusCode(504, new { error = "官网赛事接口响应超时" });
        }
    }
}