<?php

declare(strict_types=1);

namespace App\Service\WorkHours;

use App\Entity\Absence;
use App\Enum\TrackingMode;
use App\Service\Contracts\EmployeeContractResolver;
use DateMalformedStringException;
use DateTimeImmutable;

final readonly class WorkedHoursCreditPolicy
{
    public function __construct(
        private EmployeeContractResolver $contractResolver,
    ) {}

    /**
     * @throws DateMalformedStringException
     */
    public function computeCreditedMinutes(Absence $absence, string $dateYmd, bool $absentMorning, bool $absentAfternoon): int
    {
        $type = $absence->getType();
        // Certaines absences ne doivent jamais générer d'heures créditées.
        if (!$type?->getCountAsWorkedHours()) {
            return 0;
        }

        $employee = $absence->getEmployee();
        if (null === $employee) {
            return 0;
        }
        $workDate = new DateTimeImmutable($dateYmd);
        $contract = $this->contractResolver->resolveForEmployeeAndDate($employee, $workDate);
        // Les contrats suivis en "présence" ne cumulent pas d'heures en minutes.
        if (TrackingMode::TIME->value !== $contract?->getTrackingMode()) {
            return 0;
        }

        $weekday = (int) $workDate->format('N');
        // On applique la règle de crédit dépendante du contrat (35h / 39h / fallback).
        $dayMinutes = $this->resolveContractDayMinutes($contract?->getWeeklyHours(), $weekday);
        if ($dayMinutes <= 0) {
            return 0;
        }

        // Crédit en demi-journées: matin = 0.5, après-midi = 0.5.
        $halfUnits = ($absentMorning ? 1 : 0) + ($absentAfternoon ? 1 : 0);

        return (int) round(($dayMinutes / 2) * $halfUnits);
    }

    /**
     * @throws DateMalformedStringException
     */
    public function computeCreditedPresenceUnits(
        Absence $absence,
        string $dateYmd,
        bool $absentMorning,
        bool $absentAfternoon
    ): float {
        $employee = $absence->getEmployee();
        if (null === $employee) {
            return 0.0;
        }
        $contract = $this->contractResolver->resolveForEmployeeAndDate($employee, new DateTimeImmutable($dateYmd));
        if (TrackingMode::PRESENCE->value !== $contract?->getTrackingMode()) {
            return 0.0;
        }

        // Règle forfait:
        // - demi-journée d'absence => 0.5 travaillé
        // - journée complète d'absence => 0 travaillé
        if ($absentMorning xor $absentAfternoon) {
            return 0.5;
        }

        return 0.0;
    }

    public function resolveContractDayMinutes(?int $weeklyHours, int $isoWeekDay): int
    {
        // Week-end non travaillé dans cette politique.
        if ($isoWeekDay >= 6) {
            return 0;
        }

        // Règle fixe: 35h => 7h/jour.
        if (35 === $weeklyHours) {
            return 7 * 60;
        }

        // Règle fixe: 39h => 8h lundi-jeudi, 7h le vendredi.
        if (39 === $weeklyHours) {
            return 5 === $isoWeekDay ? 7 * 60 : 8 * 60;
        }

        // Cas spécifique métier: contrat 4h/semaine réparti sur 2 jours => 2h/jour.
        if (4 === $weeklyHours) {
            return 2 * 60;
        }

        // Contrat non renseigné/invalide: aucun crédit.
        if (null === $weeklyHours || $weeklyHours <= 0) {
            return 0;
        }

        // Fallback générique: répartition homogène sur 5 jours ouvrés.
        return (int) round(($weeklyHours * 60) / 5);
    }
}