<?php
/**
 * Unit 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 . "Monster.php");
require_once(PATH::ENTITY . "Team.php");
require_once(PATH::ENTITY . "Rune.php");
require_once(PATH::ENTITY . "Artifact.php");
require_once(PATH::ENTITY . "Building.php");

/**
 * A Unit.
 *
 * Represents an unit owned by the player.
 *
 * @category Entity
 */
class Unit extends Entity{

    /**
     * @var int Owner's player ID.
     */
    private $player;

    /**
     * @var int Unit ID.
     */
    private $id;

    /**
     * @var int ID of the building the unit is in, if any.
     */
    private $building;

    /**
     * @var Monster Base monster
     */
    private $monster;

    /**
     * @var int Unit's current stars.
     */
    private $stars;

    /**
     * @var int Unit's current stars.
     */
    private $level;

    /**
     * @var int Total gained experience.
     */
    private $experience;

    /**
     * @var int Gainex experience in the curent level.
     */
    private $exp_gained;

    /**
     * @var int Experience gained by the hour, if in an EXP building.
     */
    private $exp_gain_rate;

    /**
     * @var bool Internal flag to check if current level experience parameters have been loaded.
     */
    private $flag_experience = false;

    /**
     * @var int Total experience for the current level.
     */
    private $experience_level = 0;

    /**
     * @var int Experience remaining until next level.
     */
    private $experience_level_up = 0;

    /**
     * @var bool Internal flag to inidicate if it has been checked that the unit is in the storage
     * building. 
     */
    private $flag_storage = false;

    /**
     * @var bool Indicates if the unit is in storage.
     */
    private $in_storage = false;

    /**
     * @var string Unit's title.
     */
    private $title;

    /**
     * @var int Transmogification ID.
     */
    private $costume;

    /**
     * @var bool Internal flag to check if the source has been loaded into the entity.
     */
    private $flag_source = false;

    /**
     * @var int Unit source ID.
     */
    private $source_id;

    /**
     * @var Source Unit source.
     */
    private $source;

    /**
     * @var DateTime Unit creation time.
     */
    private $create_time;

    /**
     * @var string Name for Homunculus units.
     */
    private $homunculus_name;

    /**
     * @var bool Indicates if the unit is locked.
     */
    private $lock;

    /**
     * @var int[] The unit's base stats.
     */
    private $base_stats = array(
        "hp"  => 0,
        "atk" => 0,
        "def" => 0,
        "spd" => 0,
        "crr" => 0,
        "crd" => 0,
        "acc" => 0,
        "res" => 0,
        "ehp" => 0,
        "dmg" => 0,
    );

    /**
     * @var int[] The unit's stat bonus gained from runes.
     */
    private $rune_stats = array(
        "hp"  => 0,
        "atk" => 0,
        "def" => 0,
        "spd" => 0,
        "crr" => 0,
        "crd" => 0,
        "acc" => 0,
        "res" => 0,
        "ehp" => 0,
        "dmg" => 0,
    );

    /**
     * @var int[] The unit's stat bonus gained from artifacts.
     */
    private $artifact_stats = array(
        "hp"  => 0,
        "atk" => 0,
        "def" => 0,
        "spd" => 0,
        "crr" => 0,
        "crd" => 0,
        "acc" => 0,
        "res" => 0,
        "ehp" => 0,
        "dmg" => 0,
    );

    /**
     * @var bool Internal flag to check if building stats have been loaded.
     */
    private $flag_buildings = false;

    /**
     * @var int[] The unit's stat bonus gained from buildings.
     */
    private $building_stats = array(
        "hp"  => 0,
        "atk" => 0,
        "def" => 0,
        "spd" => 0,
        "crr" => 0,
        "crd" => 0,
        "acc" => 0,
        "res" => 0,
        "ehp" => 0,
        "dmg" => 0,
    );

    /**
     * @var bool Internal flag to check if all the stats have been loaded.
     */
    private $flag_stats = false;

    /**
     * @var int[] The unit's total stats.
     */
    private $stats = array(
        "hp"  => 0,
        "atk" => 0,
        "def" => 0,
        "spd" => 0,
        "crr" => 0,
        "crd" => 0,
        "acc" => 0,
        "res" => 0,
        "ehp" => 0,
        "dmg" => 0,
    );

    /**
     * @var bool Internal flag to check if runes and artifacts have been loaded.
     */
    private $flag_runes = false;

    /**
     * @var float Average rune eficiency.
     */
    private $avg_rune_efficiency = 0.0;

    /**
     * @var Rune[] Equipped runes.
     */
    private $rune = [];

    /**
     * @var Artifact Equiped archetype artifact.
     */
    private $artifact_type;

    /**
     * @var Artifact Equipped elemental artifact.
     */
    private $artifact_element;

    /**
     * @var bool Internla flag to check if the teams have been loaded into the entity.
     */
    private $flag_teams = false;

    /**
     * @var Team [] The teams the unit is in.
     */
    private $teams = [];

    /**
     * @var bool Internal flag to check if the skill levels have been loded.
     */
    private $flag_skills = false;

    /**
     * @var int[] Skill levels.
     */
    private $skill_levels = [];

    /**
     * Constructor.
     *
     * Searches the database and retrieves the information about the
     * unit, populating it and it's items.
     *
     * @param int $id Unit identifier.
     */
    public function __construct($id){
        $player = get_context()->get_player()->get_id();
        $statement = get_context()->get_db()->prepare("
          SELECT
            player,
            id,
            building,
            monster,
            stars,
            level,
            hp,
            attack,
            defense,
            speed,
            crit_rate,
            crit_damage,
            resistance,
            accuracy,
            experience,
            exp_gained,
            exp_gain_rate,
            costume,
            source,
            create_time,
            homunculus_name,
            lock
          FROM unit
          WHERE
            id = :id;
        ");
        $statement->bindValue(':id', $id, SQLITE3_TEXT);
        $statement->bindValue(':player', $player, SQLITE3_TEXT);
        $r = $statement->execute()->fetchArray(SQLITE3_ASSOC);
        if ($r){
            $this->player = $r["player"];
            $this->id = $r["id"];
            if ($r["building"] != null && $r["building"] > 0){
                $this->building = $r["building"];
            }
            if (strlen($r["monster"]) > 0){
                $this->monster = new Monster($r["monster"]);
            }
            $this->stars = $r["stars"];
            $this->level = $r["level"];
            $this->base_stats["hp"] = $r["hp"];
            $this->base_stats["atk"] = $r["attack"];
            $this->base_stats["def"] = $r["defense"];
            $this->base_stats["spd"] = $r["speed"];
            $this->base_stats["crr"] = $r["crit_rate"];
            $this->base_stats["crd"] = $r["crit_damage"];
            $this->base_stats["res"] = $r["resistance"];
            $this->base_stats["acc"] = $r["accuracy"];
            $this->base_stats["ehp"] = APPLICATION::calculate_ehp($r["hp"], $r["defense"]);
            $this->base_stats["dmg"] = APPLICATION::calculate_dmg($r["attack"], $r["crit_rate"], $r["crit_damage"]);

            $this->experience = $r["experience"];
            $this->exp_gained = $r["exp_gained"];
            $this->exp_gain_rate = $r["exp_gain_rate"];
            $this->costume = $r["costume"];
            if ($r["source"]){
                $this->source_id = $r["source"];
            }
            $this->create_time = new Datetime();
            $this->create_time->setTimestamp($r["create_time"]);
            $this->homunculus_name = $r["homunculus_name"];
            if ($this->monster->is_homunculus()){
                $this->title = $this->homunculus_name;
            }
            else{
                $this->title = $this->monster->get_title();
            }
            $this->lock = $r["lock"];

        }
    }

    /**
     * Loads the unit skills into the entity.
     *
     * Must be called only once before trying to get the skills. Sets the flag
     * {@link Unit:$flag_skills} to true.
     */
    private function load_skills(){
        $statement = get_context()->get_db()->prepare("
          SELECT level
          FROM
            unit_skill,
            skill
          WHERE
            skill.id = unit_skill.skill AND
            unit_skill.unit = :unit
          ORDER BY slot;
        ");
        $statement->bindValue(':unit', $this->id, SQLITE3_TEXT);
        $q = $statement->execute();
        while ($r = $q->fetchArray(SQLITE3_ASSOC)){
            array_push($this->skill_levels, $r["level"]);
        }
        $this->flag_skills = true;
    }

    /**
     * Loads the unit's current level experience parameters into the entity.
     *
     * Must be called only once before trying to get experience parameters. Sets the flag
     * {@link Unit:$flag_experience} to true.
     */
    private function load_experience(){
        $statement = get_context()->get_db()->prepare("
          SELECT exp
          FROM experience
          WHERE
            stars = :stars AND
            level = :level;
        ");
        $statement->bindValue(':stars', $this->stars, SQLITE3_TEXT);
        $statement->bindValue(':level', $this->level, SQLITE3_TEXT);
        $r = $statement->execute()->fetchArray(SQLITE3_ASSOC);
        if ($r){
            $this->experience_level = $r["exp"];
            $this->experience_level_up = $r["exp"] - $this->exp_gained;
        }
        $this->flag_experience = true;
    }

    /**
     * Loads the unit storage status into the entity.
     *
     * Must be called only once before trying to get the skills. Sets the flag
     * {@link Unit:$flag_storage} to true.
     */
    private function load_storage(){
        $statement = get_context()->get_db()->prepare("
          SELECT 1
          FROM
            unit,
            building
          WHERE
            unit.id = :id AND
            unit.player = :player AND
            building.player = :player AND
            unit.building = building.id AND
            building.buildable = :buildable;
        ");
        $statement->bindValue(':id', $this->id, SQLITE3_TEXT);
        $statement->bindValue(':player', $this->player, SQLITE3_TEXT);
        $statement->bindValue(':buildable', BUILDING_ID::MONSTER_STORAGE, SQLITE3_TEXT);
        $r = $statement->execute()->fetchArray(SQLITE3_ASSOC);
        if ($r){
            $this->in_storage = true;
        }
        else{
            $this->in_storage = false;
        }
        $this->flag_storage = true;
    }

    /**
     * Loads the building stats into the entity.
     *
     * Must be called only once before trying to get the building or total stats. Sets the flag
     * {@link Unit:$flag_buildings} to true.
     */
    private function load_buildings(){
        $statement = get_context()->get_db()->prepare("
          SELECT
            affected_stat,
            bonus,
            element
          FROM
            decorative,
            decorative_level,
            decoration
          WHERE
            decoration.player = :player AND
            decorative.id = decoration.decorative AND
            decoration.decorative = decorative_level.decorative AND
            decoration.level = decorative_level.level AND
            area = :area AND
            affected_stat IN (:stat_atk, :stat_def, :stat_hp, :stat_spd, :stat_crd);
        ");
        $statement->bindValue(':player', $this->player, SQLITE3_TEXT);
        $statement->bindValue(':area', EFFECT_AREA_ID::GENERAL, SQLITE3_INTEGER);
        $statement->bindValue(':stat_atk', STAT_ID::ATK, SQLITE3_INTEGER);
        $statement->bindValue(':stat_def', STAT_ID::DEF, SQLITE3_INTEGER);
        $statement->bindValue(':stat_hp', STAT_ID::HP, SQLITE3_INTEGER);
        $statement->bindValue(':stat_spd', STAT_ID::SPD, SQLITE3_INTEGER);
        $statement->bindValue(':stat_crd', STAT_ID::CRIT_DMG, SQLITE3_INTEGER);
        $q = $statement->execute();
        while ($r = $q->fetchArray(SQLITE3_ASSOC)){
            switch($r["affected_stat"]){
                case STAT_ID::DEF:
                    $this->building_stats["def"] += ($this->base_stats["def"]* $r["bonus"] / 100);
                    break;
                case STAT_ID::HP:
                    $this->building_stats["hp"] += ($this->base_stats["hp"]* $r["bonus"] / 100);
                    break;
                case STAT_ID::SPD:
                    $this->building_stats["spd"] += ($this->base_stats["spd"]* $r["bonus"] / 100);
                    break;
                case STAT_ID::CRIT_DMG:
                    $this->building_stats["crd"] += $r["bonus"];
                    break;
                case STAT_ID::ATK:
                    if(strlen($r["element"]) > 0 && $r["element"] == $this->monster->get_element()){
                        $this->building_stats["atk"] += ($this->base_stats["atk"]* $r["bonus"] / 100);
                    }
                    else{
                        $this->building_stats["atk"] += ($this->base_stats["atk"]* $r["bonus"] / 100);
                    }
                    break;
            }
        }
        $this->building_stats["hp"] = ceil($this->building_stats["hp"]);
        $this->building_stats["atk"] = ceil($this->building_stats["atk"]);
        $this->building_stats["def"] = ceil($this->building_stats["def"]);
        $this->building_stats["spd"] = ceil($this->building_stats["spd"]);
        $this->building_stats["ehp"] = APPLICATION::calculate_ehp($this->building_stats["hp"], $this->building_stats["def"]);
        $this->building_stats["dmg"] = APPLICATION::calculate_dmg($this->building_stats["atk"], $this->building_stats["crr"], $this->building_stats["crd"]);
        $this->flag_buildings = true;
    }

    /**
     * Loads the unit source into the entity.
     *
     * Must be called only once before trying to get the source. Sets the flag
     * {@link Unit:$flag_source} to true.
     */
    private function load_source(){
        if ($this->source_id != null){
            $this->source = new Source($this->source_id);
        }
        $this->flag_source = true;
    }

    /**
     * Loads the unit runes and artifacts into the entity.
     *
     * Must be called only once before trying to the runes or artifact or their stats. Sets the
     * flag {@link Unit:$flag_skills} to true.
     */
    private function load_runes(){
        // Runes
        $statement = get_context()->get_db()->prepare("
          SELECT rune
          FROM unit_rune
          WHERE
            unit = :unit AND
            rta = :rta;
        ");
        $statement->bindValue(':unit', $this->id, SQLITE3_TEXT);
        $statement->bindValue(':rta', get_context()->get_game_mode(), SQLITE3_TEXT);
        $q = $statement->execute();
        while ($r = $q->fetchArray(SQLITE3_ASSOC)){
            array_push($this->rune, new Rune($r["rune"]));
        }
        foreach ($this->rune as $rune){
            foreach ($rune->get_stats() as $stat){
                $this->sum_rune_stat($stat->get_stat(), $stat->get_value() + $stat->get_grind());
            }
        }
        $this->rune_stats["atk"] = ceil($this->rune_stats["atk"]);
        $this->rune_stats["def"] = ceil($this->rune_stats["def"]);
        $this->rune_stats["hp"] = ceil($this->rune_stats["hp"]);
        $this->rune_stats["ehp"] = APPLICATION::calculate_ehp($this->rune_stats["hp"], $this->rune_stats["def"]);
        $this->rune_stats["dmg"] = APPLICATION::calculate_dmg($this->rune_stats["atk"], $this->rune_stats["crr"], $this->rune_stats["crd"]);

        // Artifacts
        $this->artifact = [];
        $statement = get_context()->get_db()->prepare("
          SELECT artifact
          FROM unit_artifact
          WHERE
            unit = :unit AND
            rta = :rta;
        ");
        $statement->bindValue(':unit', $this->id, SQLITE3_TEXT);
        $statement->bindValue(':rta', get_context()->get_game_mode(), SQLITE3_TEXT);
        $q = $statement->execute();
        while ($r = $q->fetchArray(SQLITE3_ASSOC)){
            $artifact = new Artifact($r["artifact"]);
            if ($artifact->is_archetypal()){
                $this->artifact_type = $artifact;
            }
            else{
                $this->artifact_element = $artifact;
            }
            switch($artifact->get_stat()->get_stat()){
                case ARTIFACT_STAT_ID::ATK:
                    $this->artifact_stats["atk"] += $artifact->get_stat()->get_value();
                    break;
                case ARTIFACT_STAT_ID::DEF:
                    $this->artifact_stats["def"] += $artifact->get_stat()->get_value();
                    break;
                case ARTIFACT_STAT_ID::HP:
                    $this->artifact_stats["hp"] += $artifact->get_stat()->get_value();
                    break;
            }
        }
        $this->artifact_stats["ehp"] = APPLICATION::calculate_ehp($this->artifact_stats["hp"], $this->artifact_stats["def"]);
        $this->artifact_stats["dmg"] = APPLICATION::calculate_dmg($this->artifact_stats["atk"], $this->artifact_stats["crr"], $this->artifact_stats["crd"]);

        $this->flag_runes = true;
    }

    /**
     * Calculates the unit's total stats.
     *
     * Must be called only once before trying to get the stats. Sets the flag
     * {@link Unit:$flag_stats} to true.
     */
    private function load_stats(){

        if (! $this->flag_buildings){
            $this->load_buildings();
        }
        if (! $this->flag_runes){
            $this->load_runes();
        }

        $keys = ["atk", "def", "hp", "spd", "crr", "crd", "res", "acc", "ehp", "dmg"];

        foreach ($keys as $key){
            $this->stats[$key] = $this->base_stats[$key] + $this->rune_stats[$key] + $this->artifact_stats[$key] + $this->building_stats[$key];

        }

        $this->flag_stats = true;
    }

    /**
     * Loads the unit teams into the entity.
     *
     * Must be called only once before trying to get the teams. Sets the flag
     * {@link Unit:$flag_teams} to true.
     */
    private function load_teams(){
        $statement = get_context()->get_db()->prepare("
          SELECT DISTINCT team.id AS id
          FROM
            team,
            team_unit
          WHERE
            team.player = :player AND
            team.id = team_unit.team AND
            team_unit.unit = :unit;
        ");
        $statement->bindValue(':player', $this->player, SQLITE3_TEXT);
        $statement->bindValue(':unit', $this->id, SQLITE3_TEXT);
        $q = $statement->execute();
        while ($r = $q->fetchArray(SQLITE3_ASSOC)){
            array_push($this->teams, new Team($r["id"], false));
        }
        $this->flag_teams = true;
    }

    /**
     * Calculates the stat increase by a rune property.
     *
     * @param string $stat Stat type.
     * @param int $value Stat value.
     * @param int $value Stat increase value.
     */
    private function sum_rune_stat($stat, $value){
        switch ($stat){
            case RUNE_STAT_ID::ATK:
                $this->rune_stats["atk"] += $value;
                break;
            case RUNE_STAT_ID::DEF:
                $this->rune_stats["def"] += $value;
                break;
            case RUNE_STAT_ID::HP:
                $this->rune_stats["hp"] += $value;
                break;
            case RUNE_STAT_ID::SPD:
                $this->rune_stats["spd"] += $value;
                break;
            case RUNE_STAT_ID::CRR:
                $this->rune_stats["crr"] += $value;
                break;
            case RUNE_STAT_ID::CRD:
                $this->rune_stats["crd"] += $value;
                break;
            case RUNE_STAT_ID::ACC:
                $this->rune_stats["acc"] += $value;
                break;
            case RUNE_STAT_ID::RES:
                $this->rune_stats["res"] += $value;
                break;
            case RUNE_STAT_ID::ATK_P:
                $this->rune_stats["atk"] += ($this->base_stats["atk"] * $value / 100);
                break;
            case RUNE_STAT_ID::DEF_P:
                $this->rune_stats["def"] += ($this->base_stats["def"] * $value / 100);
                break;
            case RUNE_STAT_ID::HP_P:
                $this->rune_stats["hp"] += ($this->base_stats["hp"] * $value / 100);
                break;
        }
    }

    /**
     * Checks if the unit skills are completly maxed.
     *
     * @return bool True if all skills maxed, false otherwise.
     */
    public function is_fully_skilled(){
        if (! $this->flag_skills){
            $this->load_skills();
        }
        $maxed = true;
        $skills = $this->monster->get_skills();
        for ($i = 0; $i < sizeof($skills); $i ++){
            if ($skills[$i]->get_max_level() > $this->skill_levels[$i]){
                $maxed = false;
                break;
            }
        }
        return $maxed;
    }

    /**
     * Retrieves the owner's player identifier.
     *
     * @return int Player ID.
     */
    public function get_player(){
        return $this->player;
    }

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

    /**
     * Retrieves the identifier of the building the unit is in, if any.
     *
     * @return int Building ID, null if unit not in building.
     */
    public function get_building_id(){
        return $this->building;
    }

    /**
     * Retrieves the base monster.
     *
     * @return Monster The base monster.
     */
    public function get_monster(){
        return $this->monster;
    }

    /**
     * Retrieves the unit stars (grade).
     *
     * @return int Unit stars (1-6).
     */
    public function get_stars(){
        return $this->stars;
    }

    /**
     * Retrieves the unit current level.
     *
     * @return int Unit level.
     */
    public function get_level(){
        return $this->level;
    }

    /**
     * Retrieves the unit's base stats.
     *
     * It's an associative array with the following keys:
     * atk, def, hp, spd, crr, crd, acc, res, ehp, dmg
     *
     * @return int[] Unit stats.
     */
    public function get_base_stats(){
        return $this->base_stats;
    }

    /**
     * Retrieves the unit's stats provided by runes.
     *
     * It's an associative array with the following keys:
     * atk, def, hp, spd, crr, crd, acc, res, ehp, dmg
     *
     * @return int[] Rune stats.
     */
    public function get_rune_stats(){
        if (! $this->flag_runes){
            $this->load_runes();
        }
        return $this->rune_stats;
    }

    /**
     * Retrieves the unit's stats provided by artifacts.
     *
     * It's an associative array with the following keys:
     * atk, def, hp, spd, crr, crd, acc, res, ehp, dmg
     * Note that only "atk", "def", "hp", "dmg" and "ehp" can me non-zero.
     *
     * @return int[] Artifact stats.
     */
    public function get_artifact_stats(){
        if (! $this->flag_runes){
            $this->load_runes();
        }
        return $this->artifact_stats;
    }

    /**
     * Retrieves the unit's stat bonus provided by buildings.
     * 
     * Only building bonuses are considered.
     * It's an associative array with the following keys:
     * atk, def, hp, spd, crr, crd, acc, res, ehp, dmg
     *
     * @return int[] Building stats.
     */
    public function get_building_stats(){
        if (! $this->flag_buildings){
            $this->load_buildings();
        }
        return $this->building_stats;
    }

    /**
     * Retrieves the unit's stats.
     *
     * It's an associative array with the following keys:
     * atk, def, hp, spd, crr, crd, acc, res, ehp, dmg
     *
     * Includes the unit base stats, the runes and artifact increases and the building bonuses.
     *
     * @return int[] Unit stats.
     */
    public function get_stats(){
        if (! $this->flag_stats){
            $this->load_stats();
        }
        return $this->stats;
    }

    /**
     * Retrieves the total experience earned by the unit.
     *
     * @return int Total experience.
     */
    public function get_experience(){
        return $this->experience;
    }

    /**
     * Retrieves the total experience earned by the unit since it's level is the current one..
     *
     * @return int Current level experience.
     */
    public function get_current_level_experience(){
        return $this->exp_gained;
    }

    /**
     * Retrieves the experience being gained by the hour from a building.
     *
     * @return int Experience by the hour, 0 if not in an exp building.
     */
    public function get_exp_gain_rate(){
        return $this->exp_gain_rate;
    }

    /**
     * Retrieves the current transmogrification identifier.
     *
     * @return int Transmogification ID, null if none.
     */
    public function get_costume(){
        return $this->costume;
    }

    /**
     * Retrieves the $source the unit was obtained from.
     *
     * @return Source Unit source.
     */
    public function get_source(){
        if (! $this->flag_source){
            $this->load_source();
        }
        return $this->source;
    }

    /**
     * Gets the date the unit was obtained.
     *
     * If $format is supplied, a string in the desired format will be returned. If not, the raw
     * DateTime object will e returned.
     *
     * @param string $format A date format (optional).
     * @return DateTime | string The raw date, or a formatted version.
     */
    public function get_creation_time($format = null){
        if (null == $format){
            return $this->create_time;
        }
        else{
            return $this->create_time->format($format);
        }
    }

    /**
     * Retrieves the name if the unit is an homunculus.
     *
     * @return string Homunculus name, null if not Homunculus.
     */
    public function get_homunculus_name(){
        return $this->homunculus_name;
    }

    /**
     * Checks if the unit is locked.
     *
     * @return bool True if locked, false if unlocked.
     */
    public function is_locked(){
        return $this->lock;
    }

    /**
     * Retrieves the average rune efficiency.
     *
     * @return int Average efficiency of the runes.
     */
    public function get_avg_rune_efficiency(){
        if (! $this->flag_runes){
            $this->load_runes();
        }
        return $this->avg_rune_efficiency;
    }

    /**
     * Retrieves the currently equipped runes.
     *
     * @return Rune[] Equipped runes.
     */
    public function get_runes(){
        if (! $this->flag_runes){
            $this->load_runes();
        }
        return $this->rune;
    }

    /**
     * Retrieves equipped artifacts.
     * 
     * Can be read with the indexes ARTIFACT_TYPE:ELEMENT and ARTIFACT_TYPE:ARCHETYPE.
     *
     * @see ARTIFACT_TYPE
     * @return Artifact[] Equiped artifact array. Null positions if not equipped.
     */
    public function get_artifacts(){
        if (! $this->flag_runes){
            $this->load_runes();
        }
        return [$this->artifact_element, $this->artifact_type];
    }

    /**
     * Retrieves the teams the unit is in.
     *
     * @return Team[] Teams the unit is in.
     */
    public function get_teams(){
        if (! $this->flag_teams){
            $this->load_teams();
        }
        return $this->teams;
    }

    /**
     * Retrieves the skill levels.
     *
     * @return int[] Skill levels, ordered by skill slot.
     */
    public function get_skill_levels(){
        if (! $this->flag_skills){
            $this->load_skills();
        }
        return $this->skill_levels;
    }

    /**
     * Retrieves the total experience required for the current level.
     *
     * @return int Level experience.
     */
    public function get_experience_level(){
        if (! $this->flag_experience){
            $this->load_experience();
        }
        return $this->experience_level;
    }

    /**
     * Retrieves the experience required to level-up.
     *
     * @return int Experience to level-up.
     */
    public function get_experience_level_up(){
        if (! $this->flag_experience){
            $this->load_experience();
        }
        return $this->experience_level_up;
    }

    /**
     * Checks if the unit is in storage.
     *
     * @return bool True if in storage, false otherwise.
     */
    public function is_in_storage(){
        if (! $this->flag_storage){
            $this->load_storage();
        }
        return $this->in_storage;
    }

    /**
     * Retrieves the unit's title.
     * 
     * If Homunculus,it will be it's name.
     * If awakened, it will be the awakened from name.
     * If unawakened, it will be <element> <name>.
     *
     * @return string The unit's title.
     */
    public function get_title(){
        return $this->title;
    }
}