<?php

namespace App\Services\System;

use App\Models\System\City;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Validator;

class CityService
{
    public function getList(array $params): array
    {
        $query = City::query();

        if (!empty($params['parent_id'])) {
            $query->where('parent_id', $params['parent_id']);
        }

        if (!empty($params['level'])) {
            $query->where('level', $params['level']);
        }

        if (!empty($params['keyword'])) {
            $query->where(function ($q) use ($params) {
                $q->where('name', 'like', '%' . $params['keyword'] . '%')
                    ->orWhere('code', 'like', '%' . $params['keyword'] . '%')
                    ->orWhere('pinyin', 'like', '%' . $params['keyword'] . '%');
            });
        }

        if (isset($params['status']) && $params['status'] !== '') {
            $query->where('status', $params['status']);
        }

        $query->orderBy('sort')->orderBy('id');

        $pageSize = $params['page_size'] ?? 20;
        $list = $query->paginate($pageSize);

        return [
            'list' => $list->items(),
            'total' => $list->total(),
            'page' => $list->currentPage(),
            'page_size' => $list->perPage(),
        ];
    }

    public function getTree(): array
    {
        return $this->buildTree(City::where('status', true)->orderBy('sort')->get());
    }

    public function getChildren(int $parentId): array
    {
        return City::where('parent_id', $parentId)
            ->where('status', true)
            ->orderBy('sort')
            ->get()
            ->toArray();
    }

    public function getByCode(string $code): ?City
    {
        return City::where('code', $code)->first();
    }

    public function getById(int $id): ?City
    {
        return City::find($id);
    }

    public function getByPinyin(string $pinyin): array
    {
        return City::where('pinyin', 'like', '%' . $pinyin . '%')
            ->where('status', true)
            ->get()
            ->toArray();
    }

    public function create(array $data): City
    {
        Validator::make($data, [
            'name' => 'required|string|max:100',
            'code' => 'required|string|max:50|unique:system_cities,code',
            'level' => 'required|integer|in:1,2,3',
            'parent_id' => 'sometimes|exists:system_cities,id',
        ])->validate();

        $city = City::create($data);
        $this->clearCache();
        return $city;
    }

    public function update(int $id, array $data): City
    {
        $city = City::findOrFail($id);

        Validator::make($data, [
            'name' => 'sometimes|required|string|max:100',
            'code' => 'sometimes|required|string|max:50|unique:system_cities,code,' . $id,
            'level' => 'sometimes|required|integer|in:1,2,3',
            'parent_id' => 'sometimes|exists:system_cities,id',
        ])->validate();

        $city->update($data);
        $this->clearCache();
        return $city;
    }

    public function delete(int $id): bool
    {
        $city = City::findOrFail($id);

        if ($city->children()->exists()) {
            throw new \Exception('该城市下有子级数据，不能删除');
        }

        $city->delete();
        $this->clearCache();
        return true;
    }

    public function batchDelete(array $ids): bool
    {
        City::whereIn('id', $ids)->delete();
        $this->clearCache();
        return true;
    }

    public function batchUpdateStatus(array $ids, bool $status): bool
    {
        City::whereIn('id', $ids)->update(['status' => $status]);
        $this->clearCache();
        return true;
    }

    private function buildTree(array $cities, int $parentId = 0): array
    {
        $tree = [];
        foreach ($cities as $city) {
            if ($city['parent_id'] == $parentId) {
                $children = $this->buildTree($cities, $city['id']);
                if (!empty($children)) {
                    $city['children'] = $children;
                }
                $tree[] = $city;
            }
        }
        return $tree;
    }

    private function clearCache(): void
    {
        Cache::forget('system:cities:tree');
    }

    public function getCachedTree(): array
    {
        $cacheKey = 'system:cities:tree';
        $tree = Cache::get($cacheKey);

        if ($tree === null) {
            $tree = $this->getTree();
            Cache::put($cacheKey, $tree, 3600);
        }

        return $tree;
    }

    public function getProvinces(): array
    {
        return City::where('level', 1)
            ->where('status', true)
            ->orderBy('sort')
            ->get()
            ->toArray();
    }

    public function getCities(int $provinceId): array
    {
        return City::where('parent_id', $provinceId)
            ->where('level', 2)
            ->where('status', true)
            ->orderBy('sort')
            ->get()
            ->toArray();
    }

    public function getDistricts(int $cityId): array
    {
        return City::where('parent_id', $cityId)
            ->where('level', 3)
            ->where('status', true)
            ->orderBy('sort')
            ->get()
            ->toArray();
    }
}