using MAX.Framework.Commons;
using MAX.Framework.Dtos;
using MAX.Framework.Validation;
using MAX.Plugins;
using Microsoft.AspNetCore.WebUtilities;
using Store.Modules.CloudProduct.Dtos;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace Store.Modules.CloudProduct.Services;

/// <summary>调用外部网站的图片识别额度接口，单例复用 HTTP 连接。</summary>
public sealed class ImageAnalysisQuotaService : IDisposable
{
	private readonly HttpClient client;
	private readonly PluginContext<CloudProductPlugin> context;
	private readonly string ApiKey;
	/// <summary>从站点根地址创建客户端，定期更新连接以跟随 DNS 变化。</summary>
	public ImageAnalysisQuotaService(PluginContext<CloudProductPlugin> context)
	{
		this.context = context;
		var url = context.RequireConfiguration("ImageAnalysisQuota:Url");
		ApiKey = context.RequireConfiguration("ImageAnalysisQuota:APIKey");
		if (!Uri.TryCreate(url, UriKind.Absolute, out var endpoint) ||
			(endpoint.Scheme != Uri.UriSchemeHttp && endpoint.Scheme != Uri.UriSchemeHttps))
			throw new InvalidOperationException("ImageAnalysisQuota:Url 必须是 HTTP 或 HTTPS 站点地址。");
		if (string.IsNullOrEmpty(ApiKey)) 
			throw new InvalidOperationException("ApiKey 不能为空");

		client = new HttpClient(new SocketsHttpHandler
		{
			PooledConnectionLifetime = TimeSpan.FromMinutes(5),
			AllowAutoRedirect = false
		})
		{ BaseAddress = endpoint };
	}

	/// <summary>随服务释放客户端及连接池。</summary>
	public void Dispose() => client.Dispose();

	/// <summary>
	/// 使用指定用户的识别额度，返回外部接口原始响应；HTTP 失败直接抛出异常。
	/// 额度扣减不自动重试，避免请求已执行但响应丢失时重复扣减。
	/// </summary>
	public async Task<bool> UseImageAnalysisQuotaAsync(UseImageAnalysisQuotaRequest request,
		CancellationToken cancellationToken = default)
	{
		RequestValidator.Validate(request);
		// 外部协议要求 token 和 username 放在查询字符串中，统一编码特殊字符。
		var requestUrl = QueryHelpers.AddQueryString("/wxxd_user/UseImageAnalysisQuota", new Dictionary<string, string?>
		{
			["token"] = ApiKey,
			["username"] = request.UserName
		});
		using var response = await client.PostAsync(requestUrl, null, cancellationToken);
		response.EnsureSuccessStatusCode();

		// shortcut: 尚未提供响应协议，明确业务成功字段后再添加响应 DTO 和业务失败判断。
		string html = await response.Content.ReadAsStringAsync(cancellationToken);
		var result = JsonSerializer.Deserialize<ApiResult>(html);
		if (result != null && result.Success)
		{
			return true;
		}
		throw new AppException(result.Msg);
	}
	
	/// <summary>
	/// 使用指定用户的识别额度，返回外部接口原始响应；HTTP 失败直接抛出异常。
	/// 额度扣减不自动重试，避免请求已执行但响应丢失时重复扣减。
	/// </summary>
	public async Task<int> GetUserImageAnalysisQuota(UseImageAnalysisQuotaRequest request,
		CancellationToken cancellationToken = default)
	{
		RequestValidator.Validate(request);
		// 外部协议要求 token 和 username 放在查询字符串中，统一编码特殊字符。
		var requestUrl = QueryHelpers.AddQueryString("/wxxd_user/GetUserImageAnalysisQuota", new Dictionary<string, string?>
		{
			["token"] = ApiKey,
			["username"] = request.UserName
		});
		using var response = await client.PostAsync(requestUrl, null, cancellationToken);
		response.EnsureSuccessStatusCode();

		// shortcut: 尚未提供响应协议，明确业务成功字段后再添加响应 DTO 和业务失败判断。
		string html = await response.Content.ReadAsStringAsync(cancellationToken);
		var options = new JsonSerializerOptions
		{
			PropertyNameCaseInsensitive = true
		};
		var result = JsonSerializer.Deserialize<ApiResult<int>>(html, options);
		if (result != null && result.Success)
		{
			return result.Data;
		}
		throw new AppException(result.Msg);
	}
}