<?php
/**
 * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
 *
 * Copyright (C) 2019 - 2022 Jan Böhmer (https://github.com/jbtronics)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

declare(strict_types=1);

namespace App\Entity\Parts\PartTraits;

use Doctrine\DBAL\Types\Types;
use App\Entity\Parts\MeasurementUnit;
use App\Entity\Parts\PartLot;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Serializer\Annotation\Groups;
use Symfony\Component\Serializer\Attribute\SerializedName;
use Symfony\Component\Validator\Constraints as Assert;

/**
 * This trait collects all aspects of a part related to instock, part lots.
 */
trait InstockTrait
{
    /**
     * @var Collection<int, PartLot> A list of part lots where this part is stored
     */
    #[Assert\Valid]
    #[Groups(['extended', 'full', 'import', 'part:read', 'part:write'])]
    #[ORM\OneToMany(mappedBy: 'part', targetEntity: PartLot::class, cascade: ['persist', 'remove'], orphanRemoval: true)]
    #[ORM\OrderBy(['amount' => 'DESC'])]
    protected Collection $partLots;

    /**
     * @var float The minimum amount of the part that has to be instock, otherwise more is ordered.
     *            Given in the partUnit.
     */
    #[Assert\PositiveOrZero]
    #[Groups(['extended', 'full', 'import', 'part:read', 'part:write'])]
    #[ORM\Column(type: Types::FLOAT)]
    protected float $minamount = 0;

    /**
     * @var ?MeasurementUnit the unit in which the part's amount is measured
     */
    #[Groups(['extended', 'full', 'import', 'part:read', 'part:write'])]
    #[ORM\ManyToOne(targetEntity: MeasurementUnit::class)]
    #[ORM\JoinColumn(name: 'id_part_unit')]
    protected ?MeasurementUnit $partUnit = null;

    /**
     * Get all part lots where this part is stored.
     * @phpstan-return Collection<int, PartLot>
     */
    public function getPartLots(): Collection
    {
        return $this->partLots;
    }

    /**
     * Adds the given part lot, to the list of part lots.
     * The part lot is assigned to this part.
     *
     * @return $this
     */
    public function addPartLot(PartLot $lot): self
    {
        $lot->setPart($this);
        $this->partLots->add($lot);

        return $this;
    }

    /**
     * Removes the given part lot from the list of part lots.
     *
     * @param PartLot $lot the part lot that should be deleted
     *
     * @return $this
     */
    public function removePartLot(PartLot $lot): self
    {
        $this->partLots->removeElement($lot);

        return $this;
    }

    /**
     * Gets the measurement unit in which the part's amount should be measured.
     * Returns null if no specific unit was that. That means the parts are measured simply in quantity numbers.
     */
    public function getPartUnit(): ?MeasurementUnit
    {
        return $this->partUnit;
    }

    /**
     * Sets the measurement unit in which the part's amount should be measured.
     * Set to null, if the part should be measured in quantities.
     *
     * @return $this
     */
    public function setPartUnit(?MeasurementUnit $partUnit): self
    {
        $this->partUnit = $partUnit;

        return $this;
    }

    /**
     *  Get the count of parts which must be in stock at least.
     * If an integer-based part unit is selected, the value will be rounded to integers.
     *
     * @return float count of parts which must be in stock at least
     */
    public function getMinAmount(): float
    {
        if ($this->useFloatAmount()) {
            return $this->minamount;
        }

        return round($this->minamount);
    }

    /**
     * Checks if this part uses the float amount .
     * This setting is based on the part unit (see MeasurementUnit->isInteger()).
     *
     * @return bool True if the float amount field should be used. False if the integer instock field should be used.
     */
    public function useFloatAmount(): bool
    {
        if ($this->partUnit instanceof MeasurementUnit) {
            return !$this->partUnit->isInteger();
        }

        //When no part unit is set, treat it as part count, and so use the integer value.
        return false;
    }

    /**
     * Returns true, if the total instock amount of this part is less than the minimum amount.
     */
    public function isNotEnoughInstock(): bool
    {
        return $this->getAmountSum() < $this->getMinAmount();
    }

    /**
     * Returns true, if at least one of the part lots has an unknown amount.
     * It is possible that other part lots have a known amount, then getAmountSum() will return sum of all known amounts.
     * @return bool True if at least one part lot has an unknown amount.
     */
    public function isAmountUnknown(): bool
    {
        foreach ($this->getPartLots() as $lot) {
            if ($lot->isInstockUnknown()) {
                return true;
            }
        }

        return false;
    }

    /**
     * Returns the summed amount of this part (over all part lots)
     * Part Lots that have unknown value or are expired, are not used for this value (counted as 0).
     *
     * @return float The amount of parts given in partUnit
     */
    #[Groups(['simple', 'extended', 'full', 'part:read'])]
    #[SerializedName('total_instock')]
    public function getAmountSum(): float
    {
        //TODO: Find a method to do this natively in SQL, the current method could be a bit slow
        $sum = 0;
        foreach ($this->getPartLots() as $lot) {
            //Don't use the in stock value, if it is unknown
            if ($lot->isInstockUnknown() || ($lot->isExpired() ?? false)) {
                continue;
            }

            $sum += $lot->getAmount();
        }

        if ($this->useFloatAmount()) {
            return $sum;
        }

        return round($sum);
    }

    /**
     * Returns the summed amount of all part lots that are expired. If no part lots are expired 0 is returned.
     */
    public function getExpiredAmountSum(): float
    {
        $sum = 0.0;
        foreach ($this->getPartLots() as $lot) {
            if ($lot->isExpired() && !$lot->isInstockUnknown()) {
                $sum += $lot->getAmount();
            }
        }

        if ($this->useFloatAmount()) {
            return $sum;
        }

        return round($sum);
    }

    /**
     * Set the minimum amount of parts that have to be instock.
     * See getPartUnit() for the associated unit.
     *
     * @param float $new_minamount the new count of parts which should be in stock at least
     *
     * @return $this
     */
    public function setMinAmount(float $new_minamount): self
    {
        $this->minamount = $new_minamount;

        return $this;
    }
}
