<?php
/**
 * Skill 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_Level.php");
require_once(PATH::ENTITY . "Effect.php");

/**
 * Monster skill.
 *
 * Represents a monster skill.
 *
 * @category Entity
 */
class Skill extends Entity{

    /**
     * @var int Skill identifier.
     */
    private $id;

    /**
     * @var string Skill name.
     */
    private $name;

    /**
     * @var string Skill description.
     */
    private $description;

    /**
     * @var int Skill order.
     */
    private $slot;

    /**
     * @var int Skill cooldown turns.
     */
    private $cooltime;

    /**
     * @var int Number of hits.
     */
    private $hits;

    /**
     * @var bool Wether the skill is passive or not.
     */
    private $passive;

    /**
     * @var bool Wether the skill is AOE.
     */
    private $aoe;

    /**
     * @var int Skill max level.
     */
    private $max_level;

    /**
     * @var string Skill formula.
     */
    private $multiplier_formula;

    /**
     * @var Skill The skill upgrading this one.
     */
    private $upgrade;

    /**
     * @var bool Internal flag to check if the levels have been loaded into the entity.
     */
    private $flag_levels = false;

    /**
     * @var Skill_Level[] Available skill levels.
     */
    private $level = [];

    /**
     * @var bool Internal flag to check if the skill effects have been loaded into the entity.
     */
    private $flag_effects = false;
    /**
     * @var Effect[] Associated eeffects.
     */
    private $effect = [];

    /**
     * Constructor.
     *
     * Searches the database and retrieves the information about the
     * skill, populating it and it's items.
     *
     * @param int $id Skill identifier.
     */
    public function __construct($id){

        $statement = get_context()->get_db()->prepare("
          SELECT
            id,
            name,
            description,
            slot,
            cooltime,
            hits,
            passive,
            aoe,
            max_level,
            multiplier_formula
          FROM skill
          WHERE id = :id;
        ");
        $statement->bindValue(':id', $id, SQLITE3_TEXT);
        $r = $statement->execute()->fetchArray(SQLITE3_ASSOC);
        if ($r){
            $this->id = $r["id"];
            $this->name = HTML::e($r["name"]);
            $this->description = HTML::e($r["description"]);
            $this->slot = $r["slot"];
            $this->cooltime = $r["cooltime"];
            $this->hits = $r["hits"];
            $this->passive = $r["passive"];
            $this->aoe = $r["aoe"];
            $this->max_level = $r["max_level"];
            $this->multiplier_formula = HTML::e($r["multiplier_formula"]);
        }
    }

    /**
     * Loads the levels into the entity.
     *
     * Must be called only once before trying to access the levels. Sets the flag
     * {@link Skill:$flag_levels} to true.
     */
    private function load_levels(){
        $statement = get_context()->get_db()->prepare("
          SELECT
            skill,
            level
          FROM skill_level
          WHERE skill = :skill
          ORDER BY level;
        ");
        $statement->bindValue(':skill', $this->id, SQLITE3_TEXT);
        $q = $statement->execute();
        while ($r = $q->fetchArray(SQLITE3_ASSOC)){
            array_push($this->level, new Skill_Level($r["skill"], $r["level"]));
        }
        $this->flag_levels = true;
    }

    /**
     * Loads the effects into the entity.
     *
     * Must be called only once before trying to access the effects. Sets the flag
     * {@link Skill:$flag_effects} to true.
     */
    private function load_effects(){
        $statement = get_context()->get_db()->prepare("
          SELECT DISTINCT effect
          FROM skill_effect
          WHERE skill = :skill;
        ");
        $statement->bindValue(':skill', $this->id, SQLITE3_TEXT);
        $q = $statement->execute();
        while ($r = $q->fetchArray(SQLITE3_ASSOC)){
            array_push($this->effect, new Effect($r["effect"]));
        }
        $this->flag_effects = true;
    }

    /**
     * Retrieves the skill identifier.
     *
     * @return int Skill id.
     */
    public function get_id(){
        return $this->id;
    }

    /**
     * Retrieves the skill name.
     *
     * @return string Sill name.
     */
    public function get_name(){
        return $this->name;
    }

    /**
     * Retrieves the skill description.
     *
     * @return string Skill description.
     */
    public function get_description(){
        return $this->description;
    }

    /**
     * Retrieves the skill slot.
     *
     * @return int The skill slot (1-4);
     */
    public function get_slot(){
        return $this->slot;
    }

    /**
     * Retrieves the skill cooldown time
     *
     * @return int Skill cooltime.
     */
    public function get_cooltime(){
        return $this->cooltime;
    }

    /**
     * Retrieves the number of times the skill hist.
     *
     * @return int Number of hits.
     */
    public function get_hits(){
        return $this->hits;
    }

    /**
     * Checks if the skill is passive.
     *
     * @return bool True for passive skills, false for active.
     */
    public function is_passive(){
        return $this->passive;
    }

    /**
     * Checks if the skills affects a group instead of a unit.
     *
     * @return bool True for AOE skills, false for single-target skills.
     */
    public function is_aoe(){
        return $this->aoe;
    }

    /**
     * Retrieves the maximum level of the skill.
     *
     * @return int Skill max level.
     */
    public function get_max_level(){
        return $this->max_level;
    }

    /**
     * Retrieves the skills mathematical formula.
     *
     * @return string Skill formula.
     */
    public function get_multiplier_formula(){
        return $this->multiplier_formula;
    }

    /**
     * Retrieves the skill this one upgrades to (ie, on awakening).
     *
     * @return Skill Upgraded skill, null if not upgradeable.
     */
    public function get_upgrade(){
        return $this->upgrade;
    }

    /**
     * Retrieves information about the skill levels.
     *
     * @return Skill_Level[] Levels of the skill.
     */
    public function get_levels(){
        if (! $this->flag_levels){
            $this->load_levels();
        }
        return $this->level;
    }

    /**
     * Retrieves the effects caused by the skill.
     *
     * @return Effect[] Effects caused by the skill.
     */
    public function get_effects(){
        if (! $this->flag_effects){
            $this->load_effects();
        }
        return $this->effect;
    }

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