/*
┌──────────────────────────────────────────────────────────────────┐
│  Author: Ivan Murzak (https://github.com/IvanMurzak)             │
│  Repository: GitHub (https://github.com/IvanMurzak/Unity-MCP)    │
│  Copyright (c) 2025 Ivan Murzak                                  │
│  Licensed under the Apache License, Version 2.0.                 │
│  See the LICENSE file in the project root for more information.  │
└──────────────────────────────────────────────────────────────────┘
*/

#nullable enable
using AIGD;
using System.Collections.Generic;
using System.ComponentModel;
using com.IvanMurzak.McpPlugin;
using com.IvanMurzak.ReflectorNet.Utils;
using com.IvanMurzak.Unity.MCP.Editor.Utils;
using UnityEditor;

namespace com.IvanMurzak.Unity.MCP.Editor.API
{
    public partial class Tool_Assets
    {
        // Cross-platform invalid file name characters.
        // Path.GetInvalidFileNameChars() is OS-dependent (Linux/Mac only returns '/' and '\0'),
        // but Unity projects must be portable across all platforms.
        public static readonly char[] InvalidFileNameChars = new[]
        {
            '/', '\\', '<', '>', ':', '"', '|', '?', '*',
            '\0', '\x01', '\x02', '\x03', '\x04', '\x05', '\x06', '\x07',
            '\x08', '\x09', '\x0A', '\x0B', '\x0C', '\x0D', '\x0E', '\x0F',
            '\x10', '\x11', '\x12', '\x13', '\x14', '\x15', '\x16', '\x17',
            '\x18', '\x19', '\x1A', '\x1B', '\x1C', '\x1D', '\x1E', '\x1F'
        };

        public const string AssetsCreateFolderToolId = "assets-create-folder";
        [AiTool
        (
            AssetsCreateFolderToolId,
            Title = "Assets / Create Folder",
            Enabled = false
        )]
        [AiSkillDescription("Create a new folder under a parent folder inside 'Assets/'. " +
            "The parent path must start with 'Assets/' and every intermediate folder in it must already exist. " +
            "Refreshes the AssetDatabase at the end and returns the GUID(s) of the created folder(s).")]
        [AiSkillBody("Creates a new folder in the specified parent folder. " +
            "The parent folder string must start with the 'Assets' folder, and all folders within the parent folder string must already exist. " +
            "For example, when specifying 'Assets/ParentFolder1/ParentFolder2/', the new folder will be created in 'ParentFolder2' only if ParentFolder1 and ParentFolder2 already exist. " +
            "Use it to organize scripts and assets in the project. " +
            "Does AssetDatabase.Refresh() at the end. " +
            "Returns the GUID of the newly created folder, if successful.\n\n" +
            "## Inputs\n\n" +
            "- `inputs` — list of `{ParentFolderPath, NewFolderName}` entries. Each entry is processed independently; " +
            "per-entry errors are collected in the response so a single bad input does not abort the batch.\n\n" +
            "## Validation\n\n" +
            "- `NewFolderName` must be non-empty and must not contain any of `/`, `\\`, `<`, `>`, `:`, `\"`, `|`, `?`, `*`, or control characters (these checks are cross-platform even on Linux/Mac).\n" +
            "- `ParentFolderPath` must already exist as an `AssetDatabase.IsValidFolder` path.\n" +
            "- A folder with the same target name must not already exist under the parent.")]
        [Description("Creates a new folder in the specified parent folder. " +
            "The parent folder string must start with the 'Assets' folder, and all folders within the parent folder string must already exist. " +
            "For example, when specifying 'Assets/ParentFolder1/ParentFolder2/', the new folder will be created in 'ParentFolder2' only if ParentFolder1 and ParentFolder2 already exist. " +
            "Use it to organize scripts and assets in the project. " +
            "Does AssetDatabase.Refresh() at the end. " +
            "Returns the GUID of the newly created folder, if successful.")]
        public CreateFolderResponse CreateFolders
        (
            [Description("The paths for the folders to create.")]
            CreateFolderInput[] inputs
        )
        {
            return MainThread.Instance.Run(() =>
            {
                if (inputs.Length == 0)
                    throw new System.Exception("The input array is empty.");

                var response = new CreateFolderResponse();

                foreach (var input in inputs)
                {
                    if (string.IsNullOrWhiteSpace(input.NewFolderName))
                    {
                        response.Errors ??= new();
                        response.Errors.Add($"Cannot create folder in '{input.ParentFolderPath}': folder name is empty or whitespace.");
                        continue;
                    }

                    var invalidIndex = input.NewFolderName.IndexOfAny(InvalidFileNameChars);
                    if (invalidIndex >= 0)
                    {
                        response.Errors ??= new();
                        response.Errors.Add($"Cannot create folder '{input.NewFolderName}' in '{input.ParentFolderPath}': folder name contains invalid character '{input.NewFolderName[invalidIndex]}'.");
                        continue;
                    }

                    if (!AssetDatabase.IsValidFolder(input.ParentFolderPath))
                    {
                        response.Errors ??= new();
                        response.Errors.Add($"Cannot create folder '{input.NewFolderName}': invalid parent folder path '{input.ParentFolderPath}'. The path must start with 'Assets/' and all folders in the path must already exist.");
                        continue;
                    }

                    var targetPath = $"{input.ParentFolderPath}/{input.NewFolderName}";
                    if (AssetDatabase.IsValidFolder(targetPath))
                    {
                        response.Errors ??= new();
                        response.Errors.Add($"Cannot create folder '{input.NewFolderName}' in '{input.ParentFolderPath}': a folder with the same name already exists at '{targetPath}'.");
                        continue;
                    }

                    var guid = AssetDatabase.CreateFolder(input.ParentFolderPath, input.NewFolderName);
                    if (string.IsNullOrEmpty(guid))
                    {
                        response.Errors ??= new();
                        response.Errors.Add($"Failed to create folder '{input.NewFolderName}' in '{input.ParentFolderPath}'.");
                        continue;
                    }

                    response.CreatedFolderGuids ??= new();
                    response.CreatedFolderGuids.Add(guid);
                }

                if (response.CreatedFolderGuids is { Count: > 0 })
                {
                    AssetDatabase.Refresh(ImportAssetOptions.ForceSynchronousImport);
                    EditorUtils.RepaintAllEditorWindows();
                }

                return response;
            });
        }

    }
}