using System.Globalization;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace Health.Infrastructure.Services;

/// <summary>
/// 百度云 SMS v3 短信发送客户端（HttpClient 直连 + BCE v1 签名）
/// </summary>
public sealed class BceSmsClient(HttpClient http, IConfiguration cfg, ILogger<BceSmsClient> log)
{
    private const string Path = "/api/v3/sendSms";
    private const string ContentType = "application/json; charset=utf-8";

    private readonly HttpClient _http = http;
    private readonly ILogger<BceSmsClient> _log = log;
    private readonly string _ak = cfg["BAIDU_SMS_AK"] ?? "";
    private readonly string _sk = cfg["BAIDU_SMS_SK"] ?? "";
    private readonly string _host = cfg["BAIDU_SMS_HOST"] ?? "smsv3.bj.baidubce.com";
    private readonly string _signatureId = cfg["BAIDU_SMS_SIGNATURE_ID"] ?? "";
    private readonly string _templateId = cfg["BAIDU_SMS_TEMPLATE_ID"] ?? "";

    public async Task<bool> SendAsync(string phone, string code, CancellationToken ct)
    {
        var payload = new
        {
            mobile = $"+86{phone}",
            template = _templateId,
            signatureId = _signatureId,
            contentVar = new { SMSvCode = code }
        };
        var body = Encoding.UTF8.GetBytes(JsonSerializer.Serialize(payload));

        using var req = new HttpRequestMessage(HttpMethod.Post, Path)
        {
            Content = new ByteArrayContent(body)
        };
        req.Content.Headers.TryAddWithoutValidation("Content-Type", ContentType);

        req.Headers.Host = _host;
        var now = DateTime.UtcNow;
        var timestamp = now.ToString("yyyy-MM-ddTHH:mm:ss'Z'", CultureInfo.InvariantCulture);
        req.Headers.Add("x-bce-date", timestamp);
        var auth = BceSigner.BuildAuthorization(_ak, _sk, "POST", Path, _host, now, body.Length, ContentType);
        req.Headers.TryAddWithoutValidation("Authorization", auth);

        using var resp = await _http.SendAsync(req, ct);
        var respBody = await resp.Content.ReadAsStringAsync(ct);
        if (!resp.IsSuccessStatusCode)
        {
            _log.LogError("百度短信发送失败 HTTP {Status}: {Body}", resp.StatusCode, respBody);
            return false;
        }

        using var doc = JsonDocument.Parse(respBody);
        var respCode = doc.RootElement.GetProperty("code").GetString();
        if (respCode != "1000")
        {
            _log.LogError("百度短信发送失败 code={Code}: {Body}", respCode, respBody);
            return false;
        }
        return true;
    }
}