<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\AdminMenu;
use App\Models\RoleMenuPermission;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Schema;

class AdminMenuController extends Controller
{
    public function index(Request $request): JsonResponse
    {
        $query = AdminMenu::query()
            ->where('is_visible', true)
            ->where(function ($query) {
                $query->whereNull('path')->orWhere('path', '!=', '/study-tours/categories');
            })
            ->orderBy('sort')
            ->orderBy('id');

        $user = $request->user();
        if ($user && Schema::hasTable('role_menu_permissions')) {
            $roleMenuIds = RoleMenuPermission::query()
                ->where('role', (string) $user->role)
                ->pluck('menu_id')
                ->map(fn ($id) => (int) $id)
                ->values();
            if ($roleMenuIds->isNotEmpty()) {
                $query->whereIn('id', $roleMenuIds);
            }
        }

        $menus = $query->get(['id', 'name', 'path', 'icon', 'parent_id', 'sort']);

        $visibleIds = $menus->pluck('id')->map(fn ($id) => (int) $id)->values();
        if ($visibleIds->isNotEmpty()) {
            $parentIds = $menus->pluck('parent_id')->map(fn ($id) => (int) $id)->filter(fn ($id) => $id > 0)->unique()->values();
            if ($parentIds->isNotEmpty()) {
                $parents = AdminMenu::query()
                    ->whereIn('id', $parentIds)
                    ->where('is_visible', true)
                    ->get(['id', 'name', 'path', 'icon', 'parent_id', 'sort']);
                $menus = $menus->merge($parents)->unique('id')->sortBy([['sort', 'asc'], ['id', 'asc']])->values();
            }
        }

        return response()->json($this->buildTree($menus));
    }

    public function listAll(Request $request): JsonResponse
    {
        $menus = AdminMenu::query()
            ->orderBy('sort')
            ->orderBy('id')
            ->get(['id', 'name', 'path', 'icon', 'parent_id', 'sort', 'is_visible']);

        return response()->json($menus);
    }

    public function store(Request $request): JsonResponse
    {
        $this->ensureSuperAdmin($request);
        $data = $request->validate([
            'name' => ['required', 'string', 'max:100'],
            'path' => ['nullable', 'string', 'max:255'],
            'icon' => ['nullable', 'string', 'max:100'],
            'parent_id' => ['nullable', 'integer', 'min:0'],
            'sort' => ['nullable', 'integer', 'min:0'],
            'is_visible' => ['nullable', 'boolean'],
        ]);

        $parentId = (int) ($data['parent_id'] ?? 0);
        if ($parentId > 0) {
            $exists = AdminMenu::query()->where('id', $parentId)->exists();
            abort_unless($exists, 422, '父级菜单不存在');
        }

        $menu = AdminMenu::create([
            'name' => $data['name'],
            'path' => $data['path'] ?? null,
            'icon' => $data['icon'] ?? null,
            'parent_id' => $parentId,
            'sort' => (int) ($data['sort'] ?? 0),
            'is_visible' => (bool) ($data['is_visible'] ?? true),
        ]);

        return response()->json($menu, 201);
    }

    public function update(Request $request, AdminMenu $adminMenu): JsonResponse
    {
        $this->ensureSuperAdmin($request);
        $data = $request->validate([
            'name' => ['required', 'string', 'max:100'],
            'path' => ['nullable', 'string', 'max:255'],
            'icon' => ['nullable', 'string', 'max:100'],
            'parent_id' => ['nullable', 'integer', 'min:0'],
            'sort' => ['nullable', 'integer', 'min:0'],
            'is_visible' => ['nullable', 'boolean'],
        ]);

        $parentId = (int) ($data['parent_id'] ?? 0);
        if ($parentId > 0) {
            abort_unless($parentId !== $adminMenu->id, 422, '父级菜单不能是自身');
            $exists = AdminMenu::query()->where('id', $parentId)->exists();
            abort_unless($exists, 422, '父级菜单不存在');
        }

        $adminMenu->fill([
            'name' => $data['name'],
            'path' => $data['path'] ?? null,
            'icon' => $data['icon'] ?? null,
            'parent_id' => $parentId,
            'sort' => (int) ($data['sort'] ?? 0),
            'is_visible' => (bool) ($data['is_visible'] ?? true),
        ])->save();

        return response()->json($adminMenu);
    }

    public function destroy(Request $request, AdminMenu $adminMenu): JsonResponse
    {
        $this->ensureSuperAdmin($request);
        $hasChildren = AdminMenu::query()->where('parent_id', $adminMenu->id)->exists();
        abort_if($hasChildren, 422, '请先删除子菜单');
        $adminMenu->delete();
        return response()->json(['message' => '删除成功']);
    }

    private function normalizeMenuName(string $name): string
    {
        if ($name === '黑名单管理') {
            return '用户管理';
        }

        return $name;
    }

    private function ensureSuperAdmin(Request $request): void
    {
        abort_unless($request->user()?->isSuperAdmin(), 403, '仅超级管理员可操作');
    }

    private function buildTree($menus): array
    {
        return $menus->where('parent_id', 0)->values()->map(function (AdminMenu $menu) use ($menus) {
            $children = $menus
                ->where('parent_id', $menu->id)
                ->values()
                ->map(fn (AdminMenu $child) => [
                    'id' => $child->id,
                    'name' => $this->normalizeMenuName($child->name),
                    'path' => $child->path,
                    'icon' => $child->icon,
                ])
                ->all();

            return [
                'id' => $menu->id,
                'name' => $this->normalizeMenuName($menu->name),
                'path' => $menu->path,
                'icon' => $menu->icon,
                'children' => $children,
            ];
        })->all();
    }
}