<?php

namespace App\Services;

use App\Enums\RoleName;
use App\Enums\UserStatus;
use App\Models\Role;
use App\Models\RoleAssignmentAudit;
use App\Models\User;
use Illuminate\Auth\Access\AuthorizationException;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Str;
use Illuminate\Validation\ValidationException;
use Throwable;

class RoleAssignmentService
{
    /**
     * Kullanıcı bilgileriyle çoklu rol pivotunu atomik olarak günceller ve sonucu audit kaydına yazar.
     *
     * @param  User  $actor  Değişikliği yapan kullanıcı.
     * @param  User  $subject  Bilgileri ve rolleri değiştirilecek kullanıcı.
     * @param  array<string, mixed>  $attributes  Güncellenecek güvenli kullanıcı alanları.
     * @param  array<int, int|string>  $roleIds  Seçili rollerin benzersizleştirilecek kimlikleri.
     * @return User Güncel kullanıcı ve rol ilişkileri.
     *
     * @throws Throwable Yetkilendirme, doğrulama veya kalıcılık işlemi başarısız olduğunda.
     *
     * @author Gökhan Engin - İletişim : https://bit.ly/YazılımUzmanı
     */
    public function update(User $actor, User $subject, array $attributes, array $roleIds): User
    {
        $correlationId = (string) Str::uuid();
        $previousRoles = $subject->roles()->pluck('name')->sort()->values()->all();
        $requestedRoles = $this->roleNamesForIds($roleIds);

        try {
            if (! $actor->can('update', $subject) || ! $actor->hasPermission('roles.assign')) {
                throw new AuthorizationException;
            }

            return Cache::lock('super-admin-governance', 10)->block(5, fn () => Cache::lock('user-role-update:'.$subject->id, 10)->block(5, fn () => DB::transaction(function () use ($actor, $subject, $attributes, $roleIds, $correlationId) {
                $locked = User::query()->lockForUpdate()->findOrFail($subject->id);
                $roles = Role::query()->whereIn('id', array_values(array_unique($roleIds)))->get();
                if ($roles->count() !== count(array_unique($roleIds))) {
                    throw ValidationException::withMessages(['data.roles' => __('roles.invalid')]);
                }
                if (($attributes['status'] ?? $locked->status->value) === UserStatus::Active->value && $roles->isEmpty()) {
                    throw ValidationException::withMessages(['data.roles' => __('roles.required')]);
                }

                $before = $locked->roles()->pluck('name')->sort()->values()->all();
                $after = $roles->pluck('name')->sort()->values()->all();
                $touchesSuperAdmin = in_array(RoleName::SuperAdmin->value, array_merge($before, $after), true);
                if ($touchesSuperAdmin && ! $actor->hasRole(RoleName::SuperAdmin)) {
                    throw new AuthorizationException;
                }
                if ($actor->is($locked) && in_array(RoleName::SuperAdmin->value, $before, true) && ! in_array(RoleName::SuperAdmin->value, $after, true)) {
                    throw ValidationException::withMessages(['data.roles' => __('roles.self_remove')]);
                }
                $wouldDisableSuper = in_array(RoleName::SuperAdmin->value, $before, true) && (($attributes['status'] ?? $locked->status->value) !== UserStatus::Active->value || ! in_array(RoleName::SuperAdmin->value, $after, true));
                if ($wouldDisableSuper && $this->activeSuperAdminCount($locked->id) === 0) {
                    throw ValidationException::withMessages(['data.roles' => __('roles.last_super_admin')]);
                }
                if ($actor->is($locked) && ($attributes['status'] ?? $locked->status->value) !== UserStatus::Active->value) {
                    throw ValidationException::withMessages(['data.status' => __('roles.self_suspend')]);
                }

                $locked->fill($attributes)->save();
                $locked->roles()->sync($roles->modelKeys());
                RoleAssignmentAudit::create([
                    'actor_user_id' => $actor->id, 'subject_user_id' => $locked->id, 'correlation_id' => $correlationId,
                    'previous_roles' => $before, 'new_roles' => $after, 'added_roles' => array_values(array_diff($after, $before)),
                    'removed_roles' => array_values(array_diff($before, $after)), 'result' => 'success',
                ]);

                return $locked->refresh();
            }, 3)));
        } catch (Throwable $exception) {
            RoleAssignmentAudit::create([
                'actor_user_id' => $actor->id, 'subject_user_id' => $subject->id, 'correlation_id' => $correlationId,
                'previous_roles' => $previousRoles, 'new_roles' => $requestedRoles,
                'added_roles' => array_values(array_diff($requestedRoles, $previousRoles)),
                'removed_roles' => array_values(array_diff($previousRoles, $requestedRoles)), 'result' => 'failure',
            ]);

            throw $exception;
        }
    }

    /**
     * İstemciden gelen rol kimliklerini mevcut rol kayıtlarındaki sıralı adlara dönüştürür.
     *
     * @param  array<int, int|string>  $roleIds  Çözümlenecek rol kimlikleri.
     * @return array<int, string> Veritabanında bulunan benzersiz rol adları.
     *
     * @author Gökhan Engin - İletişim : https://bit.ly/YazılımUzmanı
     */
    private function roleNamesForIds(array $roleIds): array
    {
        return Role::query()->whereIn('id', array_values(array_unique($roleIds)))
            ->pluck('name')->sort()->values()->all();
    }

    public function replaceRole(User $actor, User $subject, RoleName|string $role): void
    {
        $name = $role instanceof RoleName ? $role->value : $role;
        $this->update($actor, $subject, [], [Role::where('name', $name)->sole()->id]);
    }

    public function delete(User $actor, User $subject): void
    {
        if ($actor->is($subject)) {
            throw ValidationException::withMessages(['user' => __('roles.self_delete')]);
        }

        if (! $actor->can('delete', $subject)) {
            throw new AuthorizationException;
        }
        Cache::lock('super-admin-governance', 10)->block(5, fn () => DB::transaction(function () use ($actor, $subject) {
            $locked = User::query()->lockForUpdate()->findOrFail($subject->id);
            if (! $actor->can('delete', $locked)) {
                throw new AuthorizationException;
            }
            if ($locked->hasRole(RoleName::SuperAdmin) && $this->activeSuperAdminCount($locked->id) === 0) {
                throw ValidationException::withMessages(['user' => __('roles.last_super_admin_delete')]);
            }
            DB::table('sessions')->where('user_id', $locked->id)->delete();
            $locked->tokens()->delete();
            $locked->forceFill(['remember_token' => Str::random(60)])->saveQuietly();
            $locked->delete();
        }, 3));
    }

    private function activeSuperAdminCount(int $exceptId): int
    {
        return User::query()->where('id', '!=', $exceptId)->where('status', UserStatus::Active->value)
            ->whereHas('roles', fn ($q) => $q->where('name', RoleName::SuperAdmin->value))->lockForUpdate()->count();
    }
}