gios-asu/nectary

<?php

namespace Nectary\Models;

use Nectary\Feed;

/**
 * Json Feed class for pulling and parsing
 * JSON feeds from the web
 *
 * @implements Feed
 */
class Json_Feed implements Feed {
    private $url;
    private $items;
    private $feed_callback;

    public function __construct( $url, $feed_callback = null ) {
        $this->url           = $url;
        $this->feed_callback = $feed_callback;
    }

    /**
     * Pull the items from the web and store them
     * in this object
     *
     * @param  int|bool   $look_at  use to grab items from a section of the json
     * @throws \Exception
     */
    public function retrieve_items( $look_at = false ) {
        $json = \call_user_func( $this->feed_callback, $this->url );
        $raw  = $this->parse_feed( $json );

        $this->items = $raw;
        if ( $look_at !== false ) {
            $this->items = $raw[ $look_at ];
        }
    }

    public function sort_by_date( string $order = 'asc' ) {
        // TODO
    }

    /**
     * @return array
     */
    public function get_items() : array {
        return $this->items;
    }

    public function set_items( array $items ) {
        $this->items = $items;
    }

    /**
     * @return array
     */
    public function get_unique_items() : array {
        $unique = [];

        foreach ( $this->items as $i => $item_a ) {
            $duplicate = false;
            foreach ( $this->items as $j => $item_b ) {
                if ( $i !== $j ) {
                    // Loose equality on purpose
                    if ( $item_a == $item_b ) {
                        // Only count a duplicate if it is BEHIND the current index
                        if ( $j < $i ) {
                            // Duplicate found
                            $duplicate = true;
                            break;
                        }
                    }
                }
            }
            if ( ! $duplicate ) {
                $unique[] = $this->items[ $i ];
            }
        }

        return $unique;
    }

    /**
     * @param  string $json
     * @return mixed
     * @throws \Exception
     */
    private function parse_feed( string $json ) {
        $json = json_decode( $json, true );
        if ( empty( $json ) ) {
            error_log( 'Json was empty' );
            throw new \Exception( 'Feed could not be loaded' );
        }

        if ( $error = $this->get_error( $json ) ) {
            error_log( 'Json Errored with: ' . $error );
        }

        return $json;
    }

    private function get_error( $json ) {
        $has_error = array_key_exists( 'errors', $json )
        && array_key_exists( 0, $json['errors'] )
        && array_key_exists( 'message', $json['errors'][0] );

        if ( $has_error ) {
            return $json['errors'][0]['message'];
        }
    }
}