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<?php

/**
 * Represents a SwagTrack
 */
class SwagTrack {

    const DEFAULT_COLOR="#339933";

    private $term;

    /**
     * Construct.
     */
    private function __construct($term) {
        $this->term=$term;
    }

    /**
     * Get id.
     */
    public function getId() {
        return $this->term->term_id;
    }

    /**
     * Get underlying taxonomy term.
     */
    public function getTerm() {
        return $this->term;
    }

    /**
     * Get display color.
     */
    public function getDisplayColor() {
        if ($this->getColor())
            return $this->getColor();

        $parent=$this->getParent();
        if ($parent && $parent->getColor())
            return $parent->getColor();

        return SwagTrack::DEFAULT_COLOR;
    }

    /**
     * Get color.
     */
    public function getColor() {
        if (!isset($this->color))
            $this->color=get_term_meta($this->getId(),"color",TRUE);

        return $this->color;
    }

    /**
     * Get parent.
     */
    public function getParent() {
        return SwagTrack::getById($this->getTerm()->parent);
    }

    /**
     * Get children for a specified parent.
     */
    public static function getByParentId($parentTrackId) {
        $terms=get_terms(array(
            "taxonomy"=>"swagtrack",
            "hide_empty"=>FALSE,
            "parent"=>$parentTrackId,
        ));

        $res=array();
        foreach ($terms as $term)
            $res[]=new SwagTrack($term);

        return $res;
    }

    /**
     * Get by slug.
     * Should we use term_id or term_taxonomy_id?
     * What is term_taxonomy_id and where is it used?
     */
    public static function getBySlug($trackSlug) {
        if (!$trackSlug)
            return NULL;

        $t=get_terms(array(
            "taxonomy"=>"swagtrack",
            "slug"=>$trackSlug,
            "hide_empty"=>FALSE,
        ));

        if (!$t)
            return NULL;

        return new SwagTrack($t[0]);
    }

    /**
     * Get by id.
     */
    public static function getById($trackId) {
        if (!$trackId)
            return NULL;

        $t=get_term($trackId);

        if (!$t)
            return NULL;

        return new SwagTrack($t);
    }
}