using System;
using System.Text;
using BrewMonster;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.Networking;

namespace BrewMonster.Scripts
{
    /// <summary>
    /// Kết quả lấy contentVersion / assetsBaseUrl (từ server hoặc hardcode).
    /// Result of fetching contentVersion / assetsBaseUrl (from server or hardcoded).
    /// </summary>
    public readonly struct GameContentVersionFetchResult
    {
        public GameContentVersionFetchResult(bool ok, string contentVersion, string assetsBaseUrl, string error)
        {
            Ok = ok;
            ContentVersion = contentVersion;
            AssetsBaseUrl = assetsBaseUrl;
            Error = error;
        }

        public bool Ok { get; }
        public string ContentVersion { get; }
        public string AssetsBaseUrl { get; }
        public string Error { get; }
    }

    /// <summary>
    /// Gửi GET hoặc POST (JSON body) lên server, parse JSON phẳng (JsonUtility).
    /// Sends GET or POST (JSON body) to server and parses flat JSON (JsonUtility).
    /// </summary>
    public static class GameContentVersionServerClient
    {
        /// <summary>
        /// GET hoặc POST JSON; response: { "contentVersion": "12", "assetsBaseUrl": "https://..." }.
        /// GET or POST JSON; response shape: { "contentVersion": "12", "assetsBaseUrl": "https://..." }.
        /// </summary>
        /// <param name="usePost">false = GET; true = POST với <paramref name="postJsonBody"/> (rỗng → "{}"). / false = GET; true = POST with body (empty → "{}").</param>
        public static async UniTask<GameContentVersionFetchResult> FetchAsync(
            string url,
            int timeoutSeconds,
            bool usePost = false,
            string postJsonBody = null)
        {
            if (string.IsNullOrWhiteSpace(url))
                return new GameContentVersionFetchResult(false, null, null, "version URL is empty");

            try
            {
                UnityWebRequest req;
                if (usePost)
                {
                    string body = string.IsNullOrWhiteSpace(postJsonBody) ? "{}" : postJsonBody.Trim();
                    byte[] raw = Encoding.UTF8.GetBytes(body);
                    req = new UnityWebRequest(url, UnityWebRequest.kHttpVerbPOST);
                    req.uploadHandler = new UploadHandlerRaw(raw) { contentType = "application/json" };
                    req.downloadHandler = new DownloadHandlerBuffer();
                    req.SetRequestHeader("Content-Type", "application/json");
                }
                else
                {
                    req = UnityWebRequest.Get(url);
                }

                using (req)
                {
                    req.timeout = Mathf.Max(5, timeoutSeconds);
                    await req.SendWebRequest().ToUniTask();

                    if (req.result != UnityWebRequest.Result.Success)
                        return new GameContentVersionFetchResult(false, null, null, req.error);

                    string json = req.downloadHandler?.text;
                    if (string.IsNullOrWhiteSpace(json))
                        return new GameContentVersionFetchResult(false, null, null, "Empty response body");

                    var parsed = JsonUtility.FromJson<VersionResponseJson>(json);
                    if (parsed == null || string.IsNullOrWhiteSpace(parsed.contentVersion))
                        return new GameContentVersionFetchResult(false, null, null, "JSON missing contentVersion");

                    return new GameContentVersionFetchResult(
                        true,
                        parsed.contentVersion.Trim(),
                        string.IsNullOrWhiteSpace(parsed.assetsBaseUrl) ? null : parsed.assetsBaseUrl.Trim(),
                        null);
                }
            }
            catch (Exception e)
            {
                BMLogger.LogError($"[Cuong] GameContentVersionServerClient: {e.Message}");
                return new GameContentVersionFetchResult(false, null, null, e.Message);
            }
        }

        [Serializable]
        class VersionResponseJson
        {
            public string contentVersion;
            public string assetsBaseUrl;
        }
    }
}