<?php

declare(strict_types=1);

namespace App\Booking;

use App\Entity\ResourceType;
use App\Entity\User;
use App\Repository\BookingRepository;
use App\Repository\ResourceRepository;

/**
 * Builds the context behind the two fragments that make up a booking board: the month calendar
 * and the floor plan.
 *
 * Both are always rendered from the same context so that one htmx round trip can swap both --
 * picking a day (or a time span) updates the grid and the plan in a single out-of-band response.
 *
 * Everything here is relative to a ResourceType **and** a TimeRange. One board shows one kind of
 * resource, and with part-day bookings "is this free?" has no answer without a span -- so both
 * are carried through the occupancy counts and the plan colours alike, and the number in a
 * calendar cell always means the same thing as the colours on the plan beside it.
 */
final readonly class BoardPresenter
{
    private const WEEKS = 6;

    public function __construct(
        private BookingRepository $bookings,
        private ResourceRepository $resources,
    ) {
    }

    /**
     * @return array<string, mixed>
     */
    public function context(ResourceType $type, \DateTimeImmutable $selected, TimeRange $time, User $user): array
    {
        $selected = $selected->setTime(0, 0);
        $today = new \DateTimeImmutable('today');

        $monthStart = $selected->modify('first day of this month');
        $gridStart = $monthStart->modify('monday this week');
        $gridEnd = $gridStart->modify(\sprintf('+%d days', self::WEEKS * 7 - 1));

        $counts = $this->bookings->countPerDateInRange($gridStart, $gridEnd, $time, $type);

        $mine = [];
        foreach ($this->bookings->findForUserInRange($user, $gridStart, $gridEnd, $type) as $booking) {
            $mine[$booking->getDate()->format('Y-m-d')][] = $booking;
        }

        $weeks = [];
        $cursor = $gridStart;
        for ($week = 0; $week < self::WEEKS; ++$week) {
            $days = [];
            for ($weekday = 0; $weekday < 7; ++$weekday) {
                $key = $cursor->format('Y-m-d');
                $days[] = [
                    'date' => $cursor,
                    'in_month' => $cursor->format('Y-m') === $monthStart->format('Y-m'),
                    'is_today' => $cursor == $today,
                    'is_selected' => $cursor == $selected,
                    'is_past' => $cursor < $today,
                    'is_weekend' => (int) $cursor->format('N') >= 6,
                    'count' => $counts[$key] ?? 0,
                    'mine' => $mine[$key] ?? [],
                ];
                $cursor = $cursor->modify('+1 day');
            }
            $weeks[] = $days;
        }

        $byResource = [];
        foreach ($this->bookings->findForDate($selected, $time, $type) as $booking) {
            // Several bookings can overlap the span on one resource once times are in play; the
            // first is enough to colour the shape, and the tooltip lists them all.
            $byResource[$booking->getResource()->getId()][] = $booking;
        }

        return [
            'type' => $type,
            'selected_date' => $selected,
            'selected_time' => $time,
            'month_start' => $monthStart,
            'weeks' => $weeks,
            'is_past' => $selected < $today,
            'resources' => $this->resources->findActiveByType($type),
            'bookings_by_resource' => $byResource,
            'my_bookings_today' => $mine[$selected->format('Y-m-d')] ?? [],
        ];
    }

    /**
     * The route parameters that reproduce a board view, so links and HX-Push-Url agree.
     *
     * @return array<string, string>
     */
    public static function urlParameters(ResourceType $type, \DateTimeImmutable $date, TimeRange $time): array
    {
        $parameters = ['type' => $type->value, 'date' => $date->format('Y-m-d')];

        if (!$time->isAllDay()) {
            $parameters['from'] = $time->start();
            $parameters['to'] = $time->end();
        }

        return $parameters;
    }
}