using System;
using System.Collections.Generic;
using System.Threading;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.Networking;

namespace AlicizaX
{
    public static partial class Utility
    {
        public static partial class Http
        {
            /// <summary>
            /// 发送 GET 请求
            /// </summary>
            public static async UniTask<string> Get(string url, float timeout = 5f)
            {
                using var cts = CreateTimeoutTokenSource(timeout);
                using var request = UnityWebRequest.Get(url);
                return await SendRequest(request, cts.Token);
            }

            /// <summary>
            /// 发送 JSON 格式的 POST 请求（服务端需用 [FromBody] 接收）
            /// </summary>
            public static async UniTask<string> PostJson(string url, object jsonData, float timeout = 5f)
            {
                using var cts = CreateTimeoutTokenSource(timeout);
                var json = JsonUtility.ToJson(jsonData);
                using var request = CreateJsonPostRequest(url, json);
                return await SendRequest(request, cts.Token);
            }

            /// <summary>
            /// 发送表单格式的 POST 请求（x-www-form-urlencoded）
            /// </summary>
            public static async UniTask<string> PostForm(string url, Dictionary<string, string> formData, float timeout = 5f)
            {
                using var cts = CreateTimeoutTokenSource(timeout);
                using var request = UnityWebRequest.Post(url, formData);
                return await SendRequest(request, cts.Token);
            }

            /// <summary>
            /// 发送多部分表单的 POST 请求（multipart/form-data，支持文件上传）
            /// </summary>
            public static async UniTask<string> PostMultipart(string url, WWWForm formData, float timeout = 5f)
            {
                using var cts = CreateTimeoutTokenSource(timeout);
                using var request = UnityWebRequest.Post(url, formData);
                return await SendRequest(request, cts.Token);
            }

            //----- 私有工具方法 -----
            private static CancellationTokenSource CreateTimeoutTokenSource(float timeout)
            {
                var cts = new CancellationTokenSource();
                cts.CancelAfterSlim(TimeSpan.FromSeconds(timeout));
                return cts;
            }

            private static UnityWebRequest CreateJsonPostRequest(string url, string json)
            {
                // 手动处理 JSON（Unity 未提供直接方法）
                var request = new UnityWebRequest(url, "POST");
                byte[] jsonBytes = System.Text.Encoding.UTF8.GetBytes(json);
                request.uploadHandler = new UploadHandlerRaw(jsonBytes);
                request.downloadHandler = new DownloadHandlerBuffer();
                request.SetRequestHeader("Content-Type", "application/json");
                return request;
            }

            private static async UniTask<string> SendRequest(UnityWebRequest request, CancellationToken token)
            {
                try
                {
                    await request.SendWebRequest().WithCancellation(token);

                    if (request.result != UnityWebRequest.Result.Success)
                    {
                        Debug.LogError($"HTTP Error ({request.responseCode}): {request.error}");
                        return string.Empty;
                    }

                    return request.downloadHandler.text;
                }
                catch (OperationCanceledException) when (token.IsCancellationRequested)
                {
                    Debug.LogWarning("Request timed out.");
                    return string.Empty;
                }
            }
        }
    }
}