<?php

namespace App\Services;

use Illuminate\Support\Facades\DB;
use Illuminate\Support\Arr;
use Illuminate\Validation\ValidationException;
use Illuminate\Support\Facades\Validator;

class MenuService
{
    protected static function tenantId(array $params): ?int
    {
        return $params['tenant_id'] ?? request()->attributes->get('tenant_id');
    }

    protected static function actorId(array $params): ?int
    {
        return $params['user_id'] ?? (request()->user()->id ?? null);
    }

    public static function index(array $params)
    {
        $tenantId = self::tenantId($params);

        $q = DB::table('menus')->whereNull('deleted_at');
        if (!is_null($tenantId)) {
            $q->where(function ($w) use ($tenantId) {
                $w->whereNull('tenant_id')->orWhere('tenant_id', $tenantId);
            });
        }
        // 옵션: parent_id / is_active / hidden 필터
        if (isset($params['parent_id'])) $q->where('parent_id', $params['parent_id']);
        if (isset($params['is_active'])) $q->where('is_active', (int)$params['is_active']);
        if (isset($params['hidden']))    $q->where('hidden', (int)$params['hidden']);

        return $q->orderBy('parent_id')->orderBy('sort_order')->get();
    }

    public static function show(array $params)
    {
        $id = (int)($params['id'] ?? 0);
        $tenantId = self::tenantId($params);

        $q = DB::table('menus')->where('id', $id)->whereNull('deleted_at');
        if (!is_null($tenantId)) {
            $q->where(function ($w) use ($tenantId) {
                $w->whereNull('tenant_id')->orWhere('tenant_id', $tenantId);
            });
        }

        $row = $q->first();
        throw_if(!$row, ValidationException::withMessages(['id' => 'Menu not found']));
        return $row;
    }

    public static function store(array $params)
    {
        $tenantId = self::tenantId($params);
        $userId   = self::actorId($params);

        $v = Validator::make($params, [
            'parent_id'    => ['nullable','integer'],
            'name'         => ['required','string','max:100'],
            'slug'         => ['nullable','string','max:150'],
            'url'          => ['nullable','string','max:255'],
            'is_active'    => ['nullable','boolean'],
            'sort_order'   => ['nullable','integer'],
            'hidden'       => ['nullable','boolean'],
            'is_external'  => ['nullable','boolean'],
            'external_url' => ['nullable','string','max:255'],
            'icon'         => ['nullable','string','max:50'],
        ]);
        $data = $v->validated();

        // slug 유니크(테넌트 범위) 체크
        if (!empty($data['slug'])) {
            $exists = DB::table('menus')
                ->whereNull('deleted_at')
                ->when(!is_null($tenantId), fn($q)=>$q->where('tenant_id',$tenantId), fn($q)=>$q->whereNull('tenant_id'))
                ->where('slug',$data['slug'])
                ->exists();
            if ($exists) {
                throw ValidationException::withMessages(['slug'=>'이미 사용 중인 슬러그입니다.']);
            }
        }

        $now = now();
        $id = DB::table('menus')->insertGetId([
            'tenant_id'    => $tenantId,
            'parent_id'    => $data['parent_id'] ?? null,
            'name'         => $data['name'],
            'slug'         => $data['slug'] ?? null,
            'url'          => $data['url'] ?? null,
            'is_active'    => (int)($data['is_active'] ?? 1),
            'sort_order'   => (int)($data['sort_order'] ?? 0),
            'hidden'       => (int)($data['hidden'] ?? 0),
            'is_external'  => (int)($data['is_external'] ?? 0),
            'external_url' => $data['external_url'] ?? null,
            'icon'         => $data['icon'] ?? null,
            'created_at'   => $now,
            'updated_at'   => $now,
            'created_by'   => $userId,
            'updated_by'   => $userId,
        ]);

        return ['id' => $id];
    }

    public static function update(array $params)
    {
        $id       = (int)($params['id'] ?? 0);
        $tenantId = self::tenantId($params);
        $userId   = self::actorId($params);

        $v = Validator::make($params, [
            'parent_id'    => ['nullable','integer'],
            'name'         => ['nullable','string','max:100'],
            'slug'         => ['nullable','string','max:150'],
            'url'          => ['nullable','string','max:255'],
            'is_active'    => ['nullable','boolean'],
            'sort_order'   => ['nullable','integer'],
            'hidden'       => ['nullable','boolean'],
            'is_external'  => ['nullable','boolean'],
            'external_url' => ['nullable','string','max:255'],
            'icon'         => ['nullable','string','max:50'],
        ]);
        $data = $v->validated();

        // 대상 존재 확인 & 테넌트 범위
        $exists = DB::table('menus')->where('id',$id)->whereNull('deleted_at')
            ->when(!is_null($tenantId), fn($q)=>$q->where('tenant_id',$tenantId), fn($q)=>$q->whereNull('tenant_id'))
            ->exists();
        if (!$exists) throw ValidationException::withMessages(['id'=>'Menu not found']);

        // slug 유니크(테넌트 범위) 체크
        if (!empty($data['slug'])) {
            $dup = DB::table('menus')->whereNull('deleted_at')
                ->when(!is_null($tenantId), fn($q)=>$q->where('tenant_id',$tenantId), fn($q)=>$q->whereNull('tenant_id'))
                ->where('slug',$data['slug'])->where('id','<>',$id)->exists();
            if ($dup) throw ValidationException::withMessages(['slug'=>'이미 사용 중인 슬러그입니다.']);
        }

        $update = Arr::only($data, ['parent_id','name','slug','url','is_active','sort_order','hidden','is_external','external_url','icon']);
        $update = array_filter($update, fn($v)=>!is_null($v));
        $update['updated_at'] = now();
        $update['updated_by'] = $userId;

        DB::table('menus')->where('id',$id)->update($update);
        return ['id' => $id];
    }

    public static function destroy(array $params)
    {
        $id       = (int)($params['id'] ?? 0);
        $tenantId = self::tenantId($params);
        $userId   = self::actorId($params);

        $q = DB::table('menus')->where('id',$id)->whereNull('deleted_at');
        $q = !is_null($tenantId)
            ? $q->where('tenant_id',$tenantId)
            : $q->whereNull('tenant_id');

        $row = $q->first();
        if (!$row) throw ValidationException::withMessages(['id'=>'Menu not found']);

        DB::table('menus')->where('id',$id)->update([
            'deleted_at' => now(),
            'deleted_by' => $userId,
        ]);
        return ['id' => $id, 'deleted' => true];
    }

    /**
     * 정렬 일괄 변경
     * $params = [ ['id'=>10, 'sort_order'=>1], ... ]
     */
    public static function reorder(array $params)
    {
        if (!is_array($params) || empty($params)) {
            throw ValidationException::withMessages(['items'=>'유효한 정렬 목록이 필요합니다.']);
        }
        DB::transaction(function () use ($params) {
            foreach ($params as $it) {
                if (!isset($it['id'], $it['sort_order'])) continue;
                DB::table('menus')->where('id',(int)$it['id'])->update([
                    'sort_order' => (int)$it['sort_order'],
                    'updated_at' => now(),
                ]);
            }
        });
        return true;
    }

    /**
     * 상태 토글
     * 허용 필드: is_active / hidden / is_external
     */
    public static function toggle(array $params)
    {
        $id = (int)($params['id'] ?? 0);
        $userId = self::actorId($params);

        $payload = array_filter([
            'is_active'   => isset($params['is_active']) ? (int)$params['is_active'] : null,
            'hidden'      => isset($params['hidden']) ? (int)$params['hidden'] : null,
            'is_external' => isset($params['is_external']) ? (int)$params['is_external'] : null,
        ], fn($v)=>!is_null($v));

        if (empty($payload)) {
            throw ValidationException::withMessages(['toggle'=>'변경할 필드가 없습니다.']);
        }

        $payload['updated_at'] = now();
        $payload['updated_by'] = $userId;

        DB::table('menus')->where('id',$id)->update($payload);
        return ['id' => $id];
    }
}