<?php

declare(strict_types=1);

namespace app\miniapi\service;

use app\miniapi\auth\Principal;
use app\miniapi\model\MiniUser;
use app\miniapi\model\MiniGrant;
use app\miniapi\exception\ApiException;
use plugin\saiadmin\app\model\water\WaterEnterprise;
use plugin\saiadmin\app\model\water\WaterDriver;
use plugin\saiadmin\app\model\water\WaterAgent;
use plugin\saiadmin\app\model\water\WaterDelivery;

/** Resource permissions are loaded every request; tokens do not contain mutable roles. */
final class Access
{
    private const ROLE_MODELS = [
        'enterprise_admin' => WaterEnterprise::class,
        'enterprise_member' => WaterEnterprise::class,
        'driver' => WaterDriver::class,
        'agent' => WaterAgent::class,
    ];

    public static function roles(): array
    {
        return array_keys(self::ROLE_MODELS);
    }

    public static function resourceModel(string $role): ?string
    {
        return self::ROLE_MODELS[$role] ?? null;
    }

    public function __construct(public readonly Principal $actor)
    {
    }

    private function grants()
    {
        if (!MiniUser::query()->where('id', $this->actor->userId)->where('status', 1)->exists()) {
            throw new ApiException(40101, '登录状态已失效', 401);
        }

        return MiniGrant::query()->where('user_id', $this->actor->userId)->where('status', 1);
    }

    public function identities(): array
    {
        $rows = [];
        foreach ($this->grants()->orderBy('id')->get() as $grant) {
            $model = self::resourceModel($grant->role);
            if (!$model) {
                continue;
            }
            $resource = $model::query()->where('id', $grant->resource_id)->where('status', 1)->first();
            if ($resource) {
                $rows[] = [
                    'role' => $grant->role,
                    'resource_id' => (int) $resource->id,
                    'name' => $resource->name,
                ];
            }
        }

        if (count($rows) > 1) {
            throw new ApiException(40903, '账号绑定了多个业务身份，请联系管理员处理', 409);
        }

        return $rows;
    }

    public function enterprise(int $id, bool $write = false): WaterEnterprise
    {
        $roles = $write ? ['enterprise_admin'] : ['enterprise_admin', 'enterprise_member'];
        if (!$this->grants()->whereIn('role', $roles)->where('resource_id', $id)->exists()) {
            $this->deny();
        }
        $row = WaterEnterprise::query()->where('id', $id)->where('status', 1)->first();
        if (!$row) {
            $this->deny();
        }

        return $row;
    }

    public function isEnterpriseAdmin(int $id): bool
    {
        return $this->grants()->where([
            'role' => 'enterprise_admin',
            'resource_id' => $id,
        ])->exists();
    }

    public function resource(string $role, int $id)
    {
        if (!in_array($role, ['driver', 'agent'], true) || !$this->grants()->where([
            'role' => $role,
            'resource_id' => $id,
        ])->exists()) {
            $this->deny();
        }
        $model = self::resourceModel($role);
        $row = $model::query()->where('id', $id)->where('status', 1)->first();
        if (!$row) {
            $this->deny();
        }

        return $row;
    }

    public function driverTask(int $driver, int $task): WaterDelivery
    {
        $this->resource('driver', $driver);
        $row = WaterDelivery::query()->where('id', $task)->where('driver_id', $driver)->first();
        if (!$row) {
            throw new ApiException(40401, '配送任务不存在', 404);
        }

        return $row;
    }

    public function enterpriseTask(int $enterprise, int $task): WaterDelivery
    {
        $this->enterprise($enterprise);
        $row = WaterDelivery::query()->where('id', $task)->where('enterprise_id', $enterprise)->first();
        if (!$row) {
            throw new ApiException(40401, '配送任务不存在', 404);
        }

        return $row;
    }

    public function agentIds(int $id): array
    {
        $this->resource('agent', $id);
        $ids = [$id];
        $frontier = [$id];
        // Existing hierarchy is limited to three levels. Refuse malformed cycles rather than widening scope.
        for ($depth = 0;$depth < 3 && $frontier;$depth++) {
            $next = WaterAgent::query()->whereIn('parent_id', $frontier)->where('status', 1)->pluck('id')->map(fn ($v) => (int) $v)->all();
            if (array_intersect($next, $ids) || ($depth === 2 && $next)) {
                throw new ApiException(40903, '代理关系异常，请联系管理员', 409);
            }
            $ids = array_merge($ids, $next);
            $frontier = $next;
        }

        return $ids;
    }

    private function deny(): never
    {
        throw new ApiException(40301, '无权访问该业务身份或资源已停用', 403);
    }
}