<?php

namespace App\Services;

use App\Models\CrmTask;
use App\Models\User;
use Carbon\CarbonImmutable;
use Illuminate\Database\Query\Builder;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;

/** Personal follow-up only: assignment never grants authority beyond the destination. */
final class DashboardWorkQueue
{
    /**
     * @param  array<string, int>  $pages
     * @return array<string, mixed>|null
     */
    public function forActor(User $actor, array $pages): ?array
    {
        $now = CarbonImmutable::now()->startOfSecond();
        $access = app(PortalProfileAccess::class);
        $manager = $actor->can('manage-portal') && ! $access->has($actor, 'auditor');
        $groups = [];
        if (app(ScopedPortalAdministration::class)->interestOperator($actor)) {
            $query = DB::table('interest_requests')->where('assigned_to', $actor->id)->whereNull('deleted_at')
                ->whereNotIn('status', ['closed', 'cancelled', 'refused', 'converted'])
                ->select(['id', 'reference', 'next_action as title', 'status', 'next_action_due_at as due_at']);
            $groups['interests'] = $this->group($query, 'interests', $pages, $now);
        }
        if (app(VirtualDesk::class)->installed()) {
            $assigned = DB::table('desk_requests')->where('analyst_id', $actor->id);
            // Direct request consultation already permits the assigned analyst, independently of decision authority.
            if ($manager || $assigned->exists()) {
                $query = DB::table('desk_requests as r')->join('desk_cases as c', 'c.id', '=', 'r.case_id')
                    ->where('r.analyst_id', $actor->id)->whereNull('c.closed_at')
                    ->whereNotIn('r.status', ['draft', 'cancelled', 'closed'])
                    ->select(['r.id', 'r.protocol as reference', 'c.title', 'r.status', 'r.due_at']);
                $groups['desk'] = $this->group($query, 'desk', $pages, $now);
            }
        }
        if ($manager && Schema::hasTable('tasks') && Schema::hasTable('leads')) {
            $query = CrmTask::availableForWork()->join('leads as l', 'l.id', '=', 'tasks.lead_id')
                ->where('tasks.assignee_user_id', $actor->id)->whereNull('l.deleted_at')
                ->select(['tasks.id', 'tasks.title', 'tasks.status', 'tasks.due_at', 'l.id as parent_id', 'l.title as reference']);
            $groups['crm_tasks'] = $this->group($query->toBase(), 'crm_tasks', $pages, $now);
        }

        return $groups === [] ? null : ['as_of' => $now->toISOString(), 'groups' => $groups, 'desk_states' => config('virtual-desk.request_states')];
    }

    /**
     * @param  'interests'|'desk'|'crm_tasks'  $kind
     * @param  array<string, int>  $pages
     * @return array<string, mixed>
     */
    private function group(Builder $query, string $kind, array $pages, CarbonImmutable $now): array
    {
        [$deadline, $order, $idColumn] = match ($kind) {
            'interests' => ['next_action_due_at', 'next_action_due_at ASC NULLS LAST', 'id'],
            'desk' => ['r.due_at', 'r.due_at ASC NULLS LAST', 'r.id'],
            'crm_tasks' => ['tasks.due_at', 'tasks.due_at ASC NULLS LAST', 'tasks.id'],
        };
        $pageName = $kind.'_page';
        $page = $pages[$pageName] ?? 1;
        $total = (clone $query)->count();
        $overdue = (clone $query)->where($deadline, '<', $now)->count();
        $lastPage = max(1, (int) ceil($total / 5));
        // An assignment may disappear between visits. Recover to an existing page instead of trapping a stale URL.
        $page = min($page, $lastPage);
        $items = (clone $query)->orderByRaw($order)->orderBy($idColumn)
            ->offset(($page - 1) * 5)->limit(5)->get()->map(function (\stdClass $row) use ($kind, $now): array {
                $due = $row->due_at === null ? null : CarbonImmutable::parse($row->due_at);

                return ['id' => (string) $row->id, 'title' => $row->title ?: 'Acompanhar manifestação', 'reference' => $row->reference,
                    'status' => $row->status, 'due_at' => $due?->toISOString(), 'overdue' => $due?->lessThan($now) ?? false,
                    'href' => match ($kind) {
                        'interests' => '/management/interests/'.$row->id,
                        'desk' => '/balcao-virtual/pedidos/'.$row->id,
                        'crm_tasks' => '/management/crm/leads/'.$row->parent_id.'#crm-task-'.$row->id,
                    }];
            })->all();

        return ['total' => $total, 'overdue' => $overdue, 'items' => $items, 'page' => $page, 'last_page' => $lastPage,
            'previous' => $page > 1 ? route('dashboard', [...$pages, $pageName => $page - 1], absolute: false) : null,
            'next' => $page < $lastPage ? route('dashboard', [...$pages, $pageName => $page + 1], absolute: false) : null];
    }
}