<?php

namespace App\Http\Controllers;

use App\Domain\Audit\Models\AuditLog;
use App\Domain\Reservations\Enums\ReservationItemStatus;
use App\Domain\Reservations\Enums\ReservationStatus;
use App\Domain\Reservations\Models\Reservation;
use Carbon\CarbonImmutable;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Http\Request;
use Illuminate\Validation\ValidationException;
use Inertia\Inertia;
use Inertia\Response;
use Symfony\Component\HttpFoundation\StreamedResponse;

class ReportController extends Controller
{
    public function index(Request $request): Response
    {
        [$filters, $from, $to] = $this->period($request);
        $reservations = $this->query($from, $to)->get();
        $items = $reservations->flatMap->items->where('status', '!=', ReservationItemStatus::Cancelled);

        return Inertia::render('reports/index', [
            'filters' => $filters,
            'summary' => [
                'total' => $reservations->count(),
                'completed' => $reservations->where('status', ReservationStatus::Completed)->count(),
                'incidents' => AuditLog::query()->where('event', 'reservation.incident_reported')->whereBetween('created_at', [$from, $to])->count(),
                'overdue' => AuditLog::query()->where('event', 'reservation.overdue')->whereBetween('created_at', [$from, $to])->count(),
                'utilizationHours' => round($items->sum(function ($item): float {
                    $end = $item->returned_at ?? ($item->ends_at->isPast() ? $item->ends_at : now());

                    return $item->delivered_at === null ? 0 : max(0, $item->delivered_at->diffInMinutes($end) / 60);
                }), 1),
            ],
            'byStatus' => $reservations->countBy(fn ($reservation): string => $reservation->status->value)->sortDesc(),
            'byCategory' => $items->countBy(fn ($item): string => $item->asset->category_name ?? 'Sem categoria')->sortDesc()->take(10),
            'byDepartment' => $reservations->countBy(fn ($reservation): string => $reservation->requester->department ?? 'Sem departamento')->sortDesc()->take(10),
            'topAssets' => $items->countBy(fn ($item): string => "{$item->asset->asset_tag} — {$item->asset->name}")->sortDesc()->take(10),
        ]);
    }

    public function export(Request $request): StreamedResponse
    {
        [$filters, $from, $to] = $this->period($request);
        $reservations = $this->query($from, $to)->lazy(200);

        return response()->streamDownload(function () use ($reservations): void {
            $output = fopen('php://output', 'w');
            if ($output === false) {
                return;
            }
            fwrite($output, "\xEF\xBB\xBF");
            fputcsv($output, ['Referência', 'Requisitante', 'Departamento', 'Estado', 'Início', 'Fim', 'Equipamentos'], ';', '"', '');
            foreach ($reservations as $reservation) {
                fputcsv($output, [
                    $this->csvCell($reservation->reference),
                    $this->csvCell($reservation->requester->name),
                    $this->csvCell($reservation->requester->department),
                    $this->csvCell($reservation->status->value),
                    $reservation->starts_at->toIso8601String(),
                    $reservation->ends_at->toIso8601String(),
                    $this->csvCell($reservation->items->pluck('asset.asset_tag')->join(', ')),
                ], ';', '"', '');
            }
            fclose($output);
        }, "reservas-{$filters['date_from']}-{$filters['date_to']}.csv", [
            'Content-Type' => 'text/csv; charset=UTF-8',
        ]);
    }

    /** @return array{array{date_from:string,date_to:string},CarbonImmutable,CarbonImmutable} */
    private function period(Request $request): array
    {
        $filters = $request->validate([
            'date_from' => ['nullable', 'date'],
            'date_to' => ['nullable', 'date', 'after_or_equal:date_from'],
        ]);
        $from = isset($filters['date_from']) ? CarbonImmutable::parse($filters['date_from'])->startOfDay() : now()->subDays(29)->startOfDay();
        $to = isset($filters['date_to']) ? CarbonImmutable::parse($filters['date_to'])->endOfDay() : now()->endOfDay();
        if ($from->diffInDays($to) > 366) {
            throw ValidationException::withMessages(['date_to' => 'O relatório está limitado a um período máximo de 366 dias.']);
        }

        return [[
            'date_from' => $from->toDateString(),
            'date_to' => $to->toDateString(),
        ], $from, $to];
    }

    /** @return Builder<Reservation> */
    private function query(CarbonImmutable $from, CarbonImmutable $to): Builder
    {
        return Reservation::query()
            ->with(['requester:id,name,department', 'items.asset:id,name,asset_tag,category_name'])
            ->where('starts_at', '<=', $to)
            ->where('ends_at', '>=', $from)
            ->orderBy('starts_at');
    }

    private function csvCell(?string $value): string
    {
        $value ??= '';

        return preg_match('/^\s*[=+\-@]/', $value) === 1 ? "'{$value}" : $value;
    }
}