<?php
/**
 * Transformation entity file.
 *
 * Creates the entity and makes it available.
 *
 * @author Iñigo Valentin <i@inigovalentin.com>
 * @license https://www.gnu.org/licenses/gpl-3.0.en.html GNU General Public License V3
 * @package SWDB
 */

require_once(PATH::ENTITY . "Entity.php");
require_once(PATH::ENTITY . "Skill.php");
require_once(PATH::ENTITY . "Leader_Skill.php");
require_once(PATH::ENTITY . "Source.php");

/**
 * Monster transformation.
 *
 * Represents a transformation that a monster can achive in battle.
 *
 * @category Entity
 */
class Monster_Transformation extends Entity{

    /**
     * @var int Transformed monster identifier.
     */
    private $id;

    /**
     * @var int Transformed monster family id.
     */
    private $family;

    /**
     * @var int ID of the monster that transformes into this.
     */
    private $monster;

    /**
     * @var bool Internal flag to check if the skills have been loaded into the entity.
     */
    private $flag_skills = false;
    /**
     * @var Skill[] Skills in the transformed form.
     */
    private $skill = [];

    /**
     * Constructor.
     *
     * Searches the database and retrieves the information about the
     * trnsformed monster, populating it and it's items.
     *
     * @param int $id Transformed monster identifier.
     */
    public function __construct($id){
        $statement = get_context()->get_db()->prepare("
          SELECT
            id,
            family,
            monster
          FROM monster_transformation
           WHERE id = :id;
        ");
        $statement->bindValue(':id', $id, SQLITE3_TEXT);
        $r = $statement->execute()->fetchArray(SQLITE3_ASSOC);
        if ($r){
            $this->id = $r["id"];
            $this->family = $r["family"];
            $this->monster = $r["monster"];
        }
    }

    /**
     * Loads the information about the monster skills in the transformed form.
     * 
     * Must be called only once before trying to get the skills. Sets the flag
     * {@link Monster_Transformation:$flag_skills} to true.
     */
    private function load_skills(){
        $this->skill = [];
        $statement = get_context()->get_db()->prepare("
              SELECT skill
              FROM
                skill,
                monster_skill
              WHERE
                id = skill AND
                monster = :id
              ORDER BY slot;
            ");
        $statement->bindValue(':id', $this->id, SQLITE3_TEXT);
        $q = $statement->execute();
        while ($r = $q->fetchArray(SQLITE3_ASSOC)){
            array_push($this->skill, new Skill($r["skill"]));
        }
        $this->flag_skills = true;
    }

    /**
     * Retrieves the identifier of the transformed monster.
     *
     * @return string Trasnformed monster ID.
     */
    public function get_id(){
        return $this->id;
    }

    /**
     * Retrieves the transofmred monster family identifier.
     *
     * @return int Family ID.
     */
    public function get_family(){
        return $this->family;
    }

    /**
     * Retrieves the identifier of the monster that transforms into this one.
     *
     * @return int Base monster ID.
     */
    public function get_base_id(){
        return $this->monster;
    }

    /**
     * Retrieves the skills of the transformed monster.
     *
     * @return Skill[] Array of skills.
     */
    public function get_skills(){
        if (! $this->flag_skills){
            $this->load_skills();
        }
        return $this->skill;
    }

    /**
     * Gets the path to the monster image.
     *
     * @return string Image URL, or a fixed unknown image.
     */
    public function get_image(){
        return APPLICATION::img("UNIT", $this->id);
    }

}