using System;
using System.Collections;
using System.Text;
using UnityEngine;
using UnityEngine.Networking;

namespace HotUpdate.Net
{
    /// <summary>
    /// 游戏服 HTTP 鉴权：POST /register、POST /login → {token,pid}
    /// </summary>
    public static class AuthApi
    {
        public const string DefaultHttpBase = "https://game.xworld.ren";

        [Serializable]
        class AuthBody
        {
            public string username;
            public string password;
        }

        public static IEnumerator Register(string httpBase, string username, string password, Action<AuthResponse, string> onDone)
        {
            yield return PostJson(httpBase, "/register", username, password, onDone);
        }

        public static IEnumerator Login(string httpBase, string username, string password, Action<AuthResponse, string> onDone)
        {
            yield return PostJson(httpBase, "/login", username, password, onDone);
        }

        /// <summary>
        /// 优先登录；失败则注册再登录（编辑器/游客自动账号）。
        /// </summary>
        public static IEnumerator EnsureAccount(string httpBase, string username, string password, Action<AuthResponse, string> onDone)
        {
            AuthResponse loginOk = null;
            string loginErr = null;
            yield return Login(httpBase, username, password, (r, e) => { loginOk = r; loginErr = e; });
            if (loginOk != null && !string.IsNullOrEmpty(loginOk.token))
            {
                onDone?.Invoke(loginOk, null);
                yield break;
            }

            AuthResponse regOk = null;
            string regErr = null;
            yield return Register(httpBase, username, password, (r, e) => { regOk = r; regErr = e; });
            if (regOk != null && !string.IsNullOrEmpty(regOk.token))
            {
                onDone?.Invoke(regOk, null);
                yield break;
            }

            // 注册失败（例如已存在）再登录一次
            AuthResponse login2 = null;
            string login2Err = null;
            yield return Login(httpBase, username, password, (r, e) => { login2 = r; login2Err = e; });
            if (login2 != null && !string.IsNullOrEmpty(login2.token))
            {
                onDone?.Invoke(login2, null);
                yield break;
            }

            onDone?.Invoke(null, $"auth failed login={loginErr}|{login2Err} register={regErr}");
        }

        static IEnumerator PostJson(string httpBase, string path, string username, string password, Action<AuthResponse, string> onDone)
        {
            var url = (httpBase ?? DefaultHttpBase).TrimEnd('/') + path;
            var body = JsonUtility.ToJson(new AuthBody { username = username, password = password });
            var bytes = Encoding.UTF8.GetBytes(body);

            using (var req = new UnityWebRequest(url, UnityWebRequest.kHttpVerbPOST))
            {
                req.uploadHandler = new UploadHandlerRaw(bytes);
                req.downloadHandler = new DownloadHandlerBuffer();
                req.SetRequestHeader("Content-Type", "application/json");
                req.timeout = 15;
                yield return req.SendWebRequest();

#if UNITY_2020_2_OR_NEWER
                bool failed = req.result != UnityWebRequest.Result.Success;
#else
                bool failed = req.isNetworkError || req.isHttpError;
#endif
                var text = req.downloadHandler?.text;
                if (failed)
                {
                    string err = req.error;
                    if (!string.IsNullOrEmpty(text))
                    {
                        try
                        {
                            var ae = JsonUtility.FromJson<AuthError>(text);
                            if (!string.IsNullOrEmpty(ae?.error))
                                err = ae.error;
                        }
                        catch { /* ignore */ }
                    }
                    onDone?.Invoke(null, $"{(int)req.responseCode} {err}");
                    yield break;
                }

                AuthResponse resp = null;
                try { resp = JsonUtility.FromJson<AuthResponse>(text); }
                catch (Exception e)
                {
                    onDone?.Invoke(null, $"parse auth: {e.Message}");
                    yield break;
                }

                if (resp == null || string.IsNullOrEmpty(resp.token))
                {
                    onDone?.Invoke(null, "auth response missing token");
                    yield break;
                }

                onDone?.Invoke(resp, null);
            }
        }
    }
}