<?php

namespace App\Model\Event;

use App\DB;
use App\Model\Event;
use App\Model\Unit;
use App\Model\Unit\MailCarrier;
use App\Model\Village;

class SendResources extends BaseEvent
{
  public int $wood = 0;
  public int $clay = 0;
  public int $iron = 0;
  public int $food = 0;

  public int $source;
  public int $destination;

  public bool $isCanceled = false;

  /**
   * @return void
   */
  public function __invoke(): void
  {
    if ($this->isCanceled) {
      // add resources back to "destination"
      DB::query(
        'update villages set wood=wood+:wood, clay=clay+:clay, iron=iron+:iron, food=food+:food where id=:id',
        [
          'wood' => $this->wood,
          'clay' => $this->clay,
          'iron' => $this->iron,
          'food' => $this->food,
          'id' => $this->source,
        ]
      );

      // add mailCarriers back to "destination"
      $meta = DB::query('select amount, unit_id from events_meta_send_resources_carriers where event_id=:eventId', ['eventId' => $this->id])->fetchAll();
      foreach ($meta as $m) {
        $unit = DB::query('select * from village_units where id=:unitId', ['unitId' => $m['unit_id']])->fetch();

        DB::query('update village_units set amount=amount+:amount where id=:unitId', ['amount' => $m['amount'], 'unitId' => $unit['id']]);
        DB::query(
          'update village_units set amount=amount-:amount where type=:unitType and home_village_id=:homeVillageId and residence_village_id=:residenceVillageId and is_traveling=true',
          [
            'amount' => $m['amount'],
            'unitType' => $unit['type'],
            'homeVillageId' => $unit['home_village_id'],
            'residenceVillageId' => $unit['residence_village_id'],
          ]
        );
      }
    }

    else {
      // add resources to destination
      // TODO: account for storage capacity
      DB::query(
        'update villages set wood=wood+:wood, clay=clay+:clay, iron=iron+:iron, food=food+:food where id=:id',
        [
          'wood' => $this->wood,
          'clay' => $this->clay,
          'iron' => $this->iron,
          'food' => $this->food,
          'id' => $this->destination,
        ]
      );

      // create SendResourcesCarriers event with mailCarriers back to source
      $source = Village::get($this->destination);
      $destination = Village::get($this->source);

      $event = new Event();
      $event->time = (new \DateTime())->add(
        \DateInterval::createFromDateString(
          Unit::getTravelTime(new MailCarrier(), Village::getDistance($source->x, $source->y, $destination->x, $destination->y))
            . ' seconds'
        )
      );
      $event->villageId = $this->source;

      $sendResourcesMailCarriers = new SendResourcesCarriers();
      $sendResourcesMailCarriers->event = $event;
      $sendResourcesMailCarriers->sendResourcesEventId = $this->id;
      $sendResourcesMailCarriers->source = $source->id;
      $sendResourcesMailCarriers->destination = $destination->id;
      $sendResourcesMailCarriers->dbInsert();
    }
  }

  public function cancel(): void
  {
    $this->event = $this->getEvent();

    $cancelTimeDiff = $this->event->createdAt->diff(new \DateTime());
    $cancelTime = (new \DateTime())->add($cancelTimeDiff);

    $this->isCanceled = true;

    DB::query(
      'update events set time=:time where id=:id',
      ['time' => $cancelTime->format('c'), 'id' => $this->event->id]
    );
    DB::query(
      'update events_send_resources set is_canceled=:is_canceled where id=:id',
      ['is_canceled' => $this->isCanceled, 'id' => $this->id]
    );
  }

  public function dbInsert(): void
  {
    DB::query(
      'insert into events (time, village_id) VALUES (:time, :village_id)',
      ['time' => $this->event->time->format('c'), 'village_id' => $this->event->villageId]
    );

    DB::query(
      <<<SQL
      insert into events_send_resources (event_id, wood, clay, iron, food, source, destination, is_canceled)
      VALUES (:event_id, :wood, :clay, :iron, :food, :source, :destination, :is_canceled)
      SQL,
      [
        'event_id' => DB::$connection->lastInsertId(),
        'wood' => $this->wood,
        'clay' => $this->clay,
        'iron' => $this->iron,
        'food' => $this->food,
        'source' => $this->source, 'destination' => $this->destination,
        'is_canceled' => $this->isCanceled ?: 0, // @see https://www.php.net/manual/de/pdostatement.execute.php#126013
      ]
    );
    $sendResourcesEventId = DB::$connection->lastInsertId();

    $resourceCapabilities = MailCarrier::getResourceCapabilities($this->event->villageId);
    $resourcesTotal = $this->wood + $this->clay + $this->iron + $this->food;
    $necessaryMailCarriers = ceil($resourcesTotal / $resourceCapabilities);

    $mailCarriersAccountedFor = 0;
    while ($mailCarriersAccountedFor < $necessaryMailCarriers) {
      $mailCarriers = DB::fetch(
        MailCarrier::class,
        'select * from village_units where type=:type and residence_village_id=:villageId and is_traveling=false',
        ['type' => 'MailCarrier', 'villageId' => $this->source]
      );
      foreach ($mailCarriers as $mailCarrier) {
        /**@type MailCarrier $mailCarrier*/

        $currentlyNecessaryMailCarriers = $necessaryMailCarriers - $mailCarriersAccountedFor;
        $currentlyUseableMailCarriers = $currentlyNecessaryMailCarriers - $mailCarrier->amount < 0 ? $currentlyNecessaryMailCarriers : $mailCarrier->amount;
        $mailCarriersAccountedFor += $currentlyUseableMailCarriers;

        DB::query(
          <<<SQL
          insert into village_units (amount, type, home_village_id, residence_village_id, is_traveling)
          VALUES (:amount, :type, :home, :residence, true)
            on conflict (type, home_village_id, residence_village_id, is_traveling)
            do update set amount = village_units.amount+:amount
          SQL,
          [
            'amount' => $currentlyUseableMailCarriers,
            'type' => 'MailCarrier',
            'home' => $mailCarrier->homeVillageId,
            'residence' => $mailCarrier->residenceVillageId,
          ]
        );
        DB::query('update village_units set amount=amount-:amount where id=:unitId', ['amount' => $necessaryMailCarriers, 'unitId' => $mailCarrier->id]);

        DB::query(
          <<<SQL
          insert into events_meta_send_resources_carriers (event_id, unit_id, amount)
          VALUES (:event_id, :unit_id, :amount)
          SQL,
          [
            'event_id' => $sendResourcesEventId,
            'unit_id' => $mailCarrier->id,
            'amount' => $necessaryMailCarriers,
          ]
        );
      }
    }

    // remove resources from source
    DB::query(
      'update villages set wood=wood-:wood, clay=clay-:clay, iron=iron-:iron, food=food-:food where id=:id',
      [
        'wood' => $this->wood,
        'clay' => $this->clay,
        'iron' => $this->iron,
        'food' => $this->food,
        'id' => $this->source,
      ]
    );
  }

  public function dbDelete(): void
  {
    DB::query('delete from events where id=:id', ['id' => $this->eventId]);
    DB::query('delete from events_send_resources where id=:id', ['id' => $this->id]);
  }
}