using System;
using System.IO;
using System.Reflection;
using UnityEditor;
using UnityEngine;

public class BuildTool : EditorWindow
{
    private string buildVersion = "1.0.0";

    private const string PREF_BUILD_VERSION = "BuildTool_Version";

    [MenuItem("Tools/Build/一键打包资源 (AB + List)")]
    public static void ShowWindow()
    {
        var window = GetWindow<BuildTool>("一键打包资源");
        window.minSize = new Vector2(400, 100);
    }

    private void OnEnable()
    {
        buildVersion = EditorPrefs.GetString(PREF_BUILD_VERSION, "1.0.0");
    }

    private void OnGUI()
    {
        GUILayout.Label("一键打包资源 (AB → List)", EditorStyles.boldLabel);
        EditorGUILayout.Space();

        buildVersion = EditorGUILayout.TextField("版本号", buildVersion);

        EditorGUILayout.Space();
        EditorGUILayout.HelpBox("使用 Asset Bundle Browser 的设置进行构建，完成后自动生成 list.json", MessageType.Info);

        EditorGUILayout.Space();

        if (GUILayout.Button("开始打包", GUILayout.Height(35)))
        {
            if (string.IsNullOrEmpty(buildVersion))
            {
                EditorUtility.DisplayDialog("错误", "请输入版本号", "确定");
                return;
            }

            EditorPrefs.SetString(PREF_BUILD_VERSION, buildVersion);
            StartBuild();
        }
    }

    private void StartBuild()
    {
        try
        {
            // ========== 第1步：调用 ABB 构建 AssetBundle ==========
            Debug.Log("=== 第1步：调用 Asset Bundle Browser 构建 ===");
            EditorUtility.DisplayProgressBar("打包中", "构建 AssetBundle...", 0.0f);

            // 获取 ABB 窗口类型
            var abbType = Type.GetType("AssetBundleBrowser.AssetBundleBrowserMain, Unity.AssetBundleBrowser.Editor");
            if (abbType == null)
            {
                EditorUtility.ClearProgressBar();
                EditorUtility.DisplayDialog("错误", "未找到 Asset Bundle Browser，请确认已安装该包", "确定");
                return;
            }

            // 获取/创建 ABB 窗口
            var abbWindow = EditorWindow.GetWindow(abbType);

            // 通过反射获取 m_BuildTab
            var buildTabField = abbType.GetField("m_BuildTab", BindingFlags.NonPublic | BindingFlags.Instance);
            if (buildTabField == null)
            {
                EditorUtility.ClearProgressBar();
                EditorUtility.DisplayDialog("错误", "无法访问 ABB 构建选项卡", "确定");
                return;
            }
            var buildTab = buildTabField.GetValue(abbWindow);

            // 获取 ABB 输出路径和 CopyToStreaming 状态（在 ExecuteBuild 之前读取）
            string abbOutputPath = GetABBSettings(buildTab, "m_UserData", "m_OutputPath") as string;
            string fullAbbPath = !string.IsNullOrEmpty(abbOutputPath) ? Path.GetFullPath(abbOutputPath) : null;
            bool copyToStreaming = (bool)GetABBSettings(buildTab, "m_CopyToStreaming", "state");

            // 通过反射调用 ExecuteBuild（同步执行，内部会处理构建 + 拷贝到 StreamingAssets）
            var executeMethod = buildTab.GetType().GetMethod("ExecuteBuild", BindingFlags.NonPublic | BindingFlags.Instance);
            if (executeMethod == null)
            {
                EditorUtility.ClearProgressBar();
                EditorUtility.DisplayDialog("错误", "无法调用 ABB 构建方法", "确定");
                return;
            }
            executeMethod.Invoke(buildTab, null);

            AssetDatabase.Refresh();

            // ========== 第2步：生成 list.json ==========
            Debug.Log("=== 第2步：生成 list.json ===");
            EditorUtility.DisplayProgressBar("打包中", "生成 list.json...", 0.6f);

            if (string.IsNullOrEmpty(fullAbbPath) || !Directory.Exists(fullAbbPath))
            {
                EditorUtility.ClearProgressBar();
                EditorUtility.DisplayDialog("错误", "ABB 构建后未找到输出目录", "确定");
                return;
            }

            // 在 ABB 输出目录下生成 list.json
            string listJsonPath = Path.Combine(fullAbbPath, "list.json");
            AssetBundleListGenerator.GenerateList(fullAbbPath, listJsonPath, buildVersion);
            Debug.Log($"list.json 已生成: {listJsonPath}");

            // 如果 ABB 勾选了 Copy to StreamingAssets，同步复制 list.json 过去
            if (copyToStreaming)
            {
                string streamingAssetsPath = Path.GetFullPath("Assets/StreamingAssets");
                if (Directory.Exists(streamingAssetsPath))
                {
                    string destPath = Path.Combine(streamingAssetsPath, "list.json");
                    File.Copy(listJsonPath, destPath, true);
                    Debug.Log($"list.json 已同步到 StreamingAssets: {destPath}");
                }
            }

            AssetDatabase.Refresh();

            EditorUtility.ClearProgressBar();

            Debug.Log("=== 资源打包完成！ ===");
            EditorUtility.DisplayDialog("打包成功",
                $"资源打包完成\n版本号: {buildVersion}\n配置文件: {listJsonPath}" +
                (copyToStreaming ? "\n已同步到: Assets/StreamingAssets/list.json" : ""),
                "确定");
        }
        catch (Exception e)
        {
            EditorUtility.ClearProgressBar();
            Debug.LogError($"打包失败: {e.Message}\n{e.StackTrace}");
            EditorUtility.DisplayDialog("打包失败", $"发生错误: {e.Message}", "确定");
        }
    }

    /// <summary>
    /// 通过反射链式读取 ABB BuildTab 中的嵌套字段值
    /// </summary>
    private static object GetABBSettings(object buildTab, params string[] fieldPath)
    {
        object current = buildTab;
        foreach (string fieldName in fieldPath)
        {
            if (current == null) return null;
            var field = current.GetType().GetField(fieldName,
                BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
            if (field == null) return null;
            current = field.GetValue(current);
        }
        return current;
    }
}