finance_app/app/Http/Controllers/Api/CategoryController.php

<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\Category;
use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
use Illuminate\Http\Request;

class CategoryController extends Controller
{
    use AuthorizesRequests;

    /**
     * 新增分類
     * POST /api/categories
     */
    public function store(Request $request)
    {
        $validated = $request->validate([
            'name'  => 'required|string|max:255',
            'color' => 'nullable|string|max:7',
            'icon'  => 'nullable|string|max:50',
        ]);

        $category = Category::create([
            ...$validated,
            'user_id' => $request->user()->id,
        ]);

        // 🟢 修正：回傳剛剛建立的 JSON 資料與 201 狀態碼給前端 push 入陣列
        return response()->json($category, 201);
    }

    /**
     * 修改分類
     * PUT /api/categories/{category}
     */
    public function update(Request $request, Category $category)
    {
        $this->authorize('update', $category);

        $validated = $request->validate([
            'name'  => 'required|string|max:255',
            'color' => 'nullable|string|max:7',
        ]);

        $category->update($validated);

        // 🟢 修正：回傳修改後的最新資料，讓前端動態替換
        return response()->json($category);
    }

    /**
     * 刪除分類
     * DELETE /api/categories/{category}
     */
    public function destroy(Category $category)
    {
        $this->authorize('delete', $category);
        $category->delete();

        return response()->json(['message' => '分類刪除成功']);
    }
}