using System;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.AsyncOperations;

namespace BrewMonster.Scripts
{
    /// <summary>
    /// Single entry for <see cref="Addressables.InitializeAsync"/> after <see cref="GameContentBootstrap"/> gate
    /// (version fetch + optional <see cref="AddressablesRuntimeUrlRewriter"/>). Prevents early init from UI code
    /// (e.g. <c>AUIManager</c>) hitting remote URLs before CDN rewrite.
    /// </summary>
    public static class AddressablesInitService
    {
        static readonly object s_lock = new();
        static UniTaskCompletionSource<bool> s_initTcs;
        static bool s_initialized;

        public static bool IsInitialized => s_initialized;

        /// <summary>
        /// Waits bootstrap gate, then initializes Addressables once.
        /// </summary>
        public static async UniTask EnsureInitializedAsync()
        {
            if (s_initialized)
                return;

            UniTaskCompletionSource<bool> waiter;
            lock (s_lock)
            {
                if (s_initialized)
                    return;

                if (s_initTcs != null)
                {
                    waiter = s_initTcs;
                }
                else
                {
                    waiter = new UniTaskCompletionSource<bool>();
                    s_initTcs = waiter;
                }
            }

            if (waiter != s_initTcs)
            {
                await waiter.Task;
                return;
            }

            try
            {
                await GameContentBootstrap.WaitForPreAddressablesSetupIfAnyAsync();
                Debug.Log("[Cuong] AddressablesInitService: Bootstrap gate OK — InitializeAsync...");

                var handle = Addressables.InitializeAsync();
                await handle.ToUniTask();

                if (handle.Status != AsyncOperationStatus.Succeeded)
                {
                    var msg = handle.OperationException?.Message ?? "InitializeAsync failed";
                    waiter.TrySetException(new InvalidOperationException(msg));
                    lock (s_lock)
                        s_initTcs = null;
                    throw handle.OperationException ?? new InvalidOperationException(msg);
                }

                s_initialized = true;
                waiter.TrySetResult(true);
                Debug.Log("[Cuong] AddressablesInitService: InitializeAsync xong.");
            }
            catch (Exception ex)
            {
                if (!waiter.Task.Status.IsCompleted())
                    waiter.TrySetException(ex);
                lock (s_lock)
                    s_initTcs = null;
                throw;
            }
        }

        /// <summary>
        /// Sync wait for legacy <c>Init()</c> paths. Prefer async when possible.
        /// </summary>
        public static void EnsureInitializedBlocking()
        {
            EnsureInitializedAsync().GetAwaiter().GetResult();
        }
    }
}