<?php
/**
 * Class API
 *
 * @package    Smartcrawl
 * @subpackage Seomoz
 */

namespace SmartCrawl\SEOMoz;

/**
 * Class API
 */
class API {

	/**
	 * Column data.
	 *
	 * @var int[] $columns
	 */
	private $columns = array(
		'ut'   => 1,
		'uu'   => 4,
		'ufq'  => 8,
		'upl'  => 16,
		'ueid' => 32,
		'feid' => 64,
		'peid' => 128,
		'ujid' => 256,
		'uipl' => 1024,
		'uid'  => 2048,
		'pid'  => 8192,
		'us'   => 536870912,
		'fuid' => 4294967296,
		'puid' => 8589934592,
		'fipl' => 17179869184,
		'upa'  => 34359738368,
		'pda'  => 68719476736,
		'ued'  => 549755813888,
		'fed'  => 140737488355328,
		'ped'  => 2251799813685248,
		'ulc'  => 144115188075855872,
	);

	/**
	 * Deprecated column data.
	 *
	 * @var int[] $deprecated_columns
	 */
	private $deprecated_columns = array(
		'uifq'        => 512,
		'fid'         => 4096,
		'umrp,umrr'   => 16384,
		'fmrp,fmrr'   => 32768,
		'pmrp,pmrr'   => 65536,
		'utrp,utrr'   => 131072,
		'ftrp,ftrr'   => 262144,
		'ptrp,ptrr'   => 524288,
		'uemrp,uemrr' => 1048576,
		'fejp,fejr'   => 2097152,
		'pejp,pejr'   => 4194304,
		'pjp,pjr'     => 8388608,
		'fjp,fjr'     => 16777216,
		'fspsc'       => 67108864,
		'pib'         => 36028797018963968,
	);

	/**
	 * Access ID.
	 *
	 * @var string $access_id
	 */
	private $access_id;

	/**
	 * Secret key.
	 *
	 * @var string $secret_key
	 */
	private $secret_key;

	/**
	 * Init the class.
	 *
	 * @param string $access_id  Access ID.
	 * @param string $secret_key Secret key.
	 */
	public function __construct( $access_id, $secret_key ) {
		$this->access_id  = $access_id;
		$this->secret_key = $secret_key;
	}

	/**
	 * Returns the Moz 'mozRank' for the given URL.
	 *
	 * @param string $target_url Target URL.
	 *
	 * @returns mixed
	 */
	public function urlmetrics( $target_url ) {
		$transient_key = $this->transient_key( $target_url );
		\smartcrawl_kill_stuck_transient( $transient_key );
		$response = get_transient( $transient_key );
		if ( empty( $response ) ) {
			$response = $this->query( 'url-metrics', $target_url );
			// Pre-defined expiration.
			set_transient( $transient_key, $response, \SMARTCRAWL_EXPIRE_TRANSIENT_TIMEOUT );
		}

		return $response;
	}

	/**
	 * Get the transient key.
	 *
	 * @param string $target_url Target URL.
	 *
	 * @return string
	 */
	private function transient_key( $target_url ) {
		return sprintf(
			'seomoz_urlmetrics_%s',
			md5( sprintf( '%s-%s-%s', $target_url, $this->access_id, $this->secret_key ) )
		);
	}

	/**
	 * Get the col value.
	 *
	 * @return int
	 */
	private function get_cols_param() {
		$value = 0;
		foreach (
			array_merge(
				$this->columns,
				$this->deprecated_columns
			) as $response_field => $bit_flag
		) {
			$value = $value + $bit_flag;
		}

		return $value;
	}

	/**
	 * Queries the SEOMoz API.
	 *
	 * @param string $api_call API path.
	 * @param string $argument API argument.
	 *
	 * @returns mixed URL contents on success, false on failure
	 */
	private function query( $api_call, $argument ) {
		$timestamp   = time() + 600; // 10 minutes into the future
		$argument    = urlencode( $argument ); // phpcs:ignore -- The api call may fail with rawurlencode
		$cols        = $this->get_cols_param();
		$request_url = "http://lsapi.seomoz.com/linkscape/{$api_call}/{$argument}?Cols={$cols}&AccessID={$this->access_id}&Expires={$timestamp}&Signature=" . $this->generate_signature( $timestamp );
		$response    = wp_remote_get( $request_url );

		return ! is_wp_error( $response ) ? json_decode( wp_remote_retrieve_body( $response ) ) : false;
	}

	/**
	 * Builds the signature var needed to authenticate.
	 *
	 * @param int $timestamp Timestamp.
	 *
	 * @returns string URL encoded Signature key/value pair
	 */
	private function generate_signature( $timestamp ) {
		// One minute into the future.
		$timestamp = isset( $timestamp ) ? $timestamp : time() + 300;
		$hash      = hash_hmac( 'sha1', $this->access_id . "\n" . $timestamp, $this->secret_key, true );

		// phpcs:ignore -- The api call may fail with rawurlencode and base64_encode is required
		return urlencode( base64_encode( $hash ) );
	}

	/**
	 * Check if response data is valid.
	 *
	 * @param object $response Response data.
	 *
	 * @return bool
	 */
	public function is_response_valid( $response ) {
		return isset( $response->uu );
	}

	/**
	 * Get the error type from response.
	 *
	 * @param object $response Response data.
	 *
	 * @return int
	 */
	public static function get_error_type( $response ) {
		$response = (array) $response;
		$status   = (int) \smartcrawl_get_array_value( $response, 'status' );

		if ( $status >= 400 && $status <= 499 ) {
			return 400;
		}

		if ( $status >= 500 && $status <= 599 ) {
			return 500;
		}

		return 0;
	}
}