<?php

namespace App\Model;

use App\DB;
use App\Model;
use App\Support\ResourceType;

class Unit
{
  public int $id;

  public int $amount;
  public string $type;
  public bool $isTraveling;

  public int $homeVillageId;
  public int $residenceVillageId;

  public string $createdAt;
  public string $updatedAt;

  public string $buildingType;

  public int $buildTimeFactor;

  public int $travelTime;

  public int $populationDemandFactor;

  public array $resourceRequirementsBase = [];
  public array $resourceRequirementsFactor = [];


  public static function getEmpty(int $villageId, string $unitType): Unit
  {
    $unit = new Unit();
    $unit->type = $unitType;
    $unit->isTraveling = false;
    $unit->homeVillageId = $villageId;
    $unit->amount = 0;

    return $unit->cast();
  }


  public function getBuildTime(int $amount): int
  {
    $building = $this->getBuilding();

    if (! $building) {
      return -1;
    }

    return intval((($_ENV['BASE_UNIT_BUILD_TIME_FACTOR'] * $this->buildTimeFactor) / ($building->level ?: 1)) * $amount);
  }


  public static function getTravelTime(Unit $unit, int $distance): int
  {
    return self::getTravelTimePerCell($unit) * $distance;
  }

  public static function getTravelTimePerCell(Unit $unit): int
  {
    return intval(ceil($unit->travelTime * $_ENV['BASE_UNIT_TRAVEL_TIME_FACTOR']));
  }


  /**
   * @return array<string, int>
   */
  public static function getResourceRequirements(Unit $unit, int $amount): array
  {
    /**@var Building $building*/
    $building = DB::fetch(
      Building::resolveType($unit->buildingType),
      'select level from village_buildings where type=:type and village_id=:id',
      ['type' => $unit->buildingType, 'id' => $unit->homeVillageId]
    )[0] ?? null;

    $currentAmount = DB::query(
      'select sum(amount) from village_units where type=:type and home_village_id=:id',
      ['type' => $unit->type, 'id' => $unit->homeVillageId]
    )->fetchColumn();

    $resourceRequirements = [];
    foreach (ResourceType::asProperties() as $resourceType) {
      $base = $unit->resourceRequirementsBase[$resourceType];
      $factor = $unit->resourceRequirementsFactor[$resourceType];

      $r = $base;
      for ($i = 0; $i <= $amount; $i++) {
        $r += ceil(
          (
            pow(
              $_ENV['BASE_UNIT_RESOURCE_REQUIREMENT_BASE'],
              $currentAmount + 1
            )
              * $factor * $_ENV['BASE_UNIT_RESOURCE_REQUIREMENT_FACTOR']
          )
            / ($building->level ?? 1)
        );
      }

      $resourceRequirements[$resourceType] = $r;
    }

    return $resourceRequirements;
  }


  public function getPopulationDemand(): int
  {
    return $this->getPopulationDemandForAmount($this->amount);
  }

  public function getPopulationDemandForAmount(int $amount): int
  {
    return $amount * $this->populationDemandFactor;
  }


  /* Relations */

  public function getHomeVillage(): Village
  {
    return DB::fetch(Village::class, 'select * from villages where id=:id', ['id' => $this->homeVillageId])[0];
  }

  public function getResidenceVillage(): Village
  {
    return DB::fetch(Village::class, 'select * from villages where id=:id', ['id' => $this->residenceVillageId])[0];
  }

  public function getBuilding(): ?Building
  {
    return Village::getBuilding($this->homeVillageId, $this->buildingType);
  }

  public function cast(): Unit
  {
    $class = Unit::resolveType($this->type);

    return Model::castToType($this, Unit::resolveType($this->type));
  }

  public static function resolveType(string $type): string
  {
    return __NAMESPACE__ . '\\Unit\\' . $type;
  }


  /* Static */

  public static function getAmountResiding(string $unitType, int $villageId): int
  {
    $statement = DB::query(
      'select SUM(amount) from village_units where type=:type and residence_village_id=:id and is_traveling=false',
      ['type' => $unitType, 'id' => $villageId]
    );
    $result = $statement->fetch()['sum'];

    return intval($result);
  }

}