<?php
/**
 * Created by PhpStorm.
 * User: Linnea
 * Date: 5/7/2015
 * Time: 10:12 AM
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit();
} // Exit if accessed directly
require_once( "aws_signed_request.php" );
require_once( "amazon-link-checker.php" );
require_once( "AmazonLinkCheckerDatabase.php" );
require_once( "AZLC_semaphore.php" );

if ( ! class_exists( 'AzWorker' ) ) :

	/**
	 * Class AzWorker
	 */
	class AzWorker {


		/**
		 * @var
		 */
		var $azlkch_options;

		/**
		 * @var int The length of time to sleep between lookups in seconds
		 */
		var $sleep = 5;


		/**
		 * @param $options
		 */
		function __construct( $options ) {
			$this->azlkch_options = $options;

		}


		function prepareForWork() {

			//Close the session to prevent lock-ups.
			//PHP sessions are blocking. session_start() will wait until all other scripts that are using the same session
			//are finished. As a result, a long-running script that unintentionally keeps the session open can cause
			//the entire site to "lock up" for the current user/browser. WordPress itself doesn't use sessions, but some
			//plugins do, so we should explicitly close the session (if any) before starting the worker.
			if ( session_id() != '' ) {
				session_write_close();
			}

			global $azlc_logger;
			// throw exception if locked
			if ( ! AZLC_semaphore::not_locked() ) {
				$azlc_logger->write( "locked so throwing an exception" );
				throw new Exception( "Locked" );
			}
			AZLC_semaphore::lock();


			//Don't stop the script when the connection is closed
			ignore_user_abort( true );

			// We don't use this code because we do send a reply back to the server
			// however, I'm saving this bit here because it may be useful in the future
			//
			//Close the connection as per http://www.php.net/manual/en/features.connection-handling.php#71172
			//This reduces resource usage.
			//(Disable when debugging or you won't get the FirePHP output)
			/*
			if (
				!headers_sent()
				&& (defined('DOING_AJAX') && constant('DOING_AJAX'))
				&& (!defined('BLC_DEBUG') || !constant('BLC_DEBUG'))
			){
				@ob_end_clean(); //Discard the existing buffer, if any
				header("Connection: close");
				ob_start();
				echo ('Connection closed'); //This could be anything
				$size = ob_get_length();
				header("Content-Length: $size");
				ob_end_flush(); // Strange behaviour, will not work
				flush();        // Unless both are called !
			}
		}
		*/


			// check that options are not empty, if any are empty, throw exception

			if ( empty( $this->azlkch_options['AWSAccessKeyId'] ) || empty( $this->azlkch_options['AWSSecretKey'] ) || empty( $this->azlkch_options['associate_tag'] ) ) {

				$azlc_logger->write( "Exception option not filled in." );
				throw new UnexpectedValueException( "Options not filled in" );
			}

		}

		function AZcredentials_are_working() {
			// this looks up a harry potter book to check if the AZ credentials for the Amazon Product API are working
			$asin   = '059035342X'; // ASIN for "Harry Potter and the Sorcerer's Stone"
			$region = 'com';
			$params = array(
				"Service"       => "AWSECommerceService",
				"Operation"     => "ItemLookup",
				"ResponseGroup" => "ItemAttributes",
				"ItemId"        => $asin,
				"IdType"        => "ASIN",
			);
			$url    = aws_signed_request( $region, $params, $this->azlkch_options['AWSAccessKeyId'], $this->azlkch_options['AWSSecretKey'],
				$this->azlkch_options['associate_tag'], '2011-08-01' );

			$response = wp_remote_get( $url );
			$body     = wp_remote_retrieve_body( $response );
			$xml      = simplexml_load_string( $body );

			$title = isset( $xml->Items->Item->ItemAttributes->Title ) ? (String) ( $xml->Items->Item->ItemAttributes->Title ) : null;

			if ( ! is_null( $title ) ) {
				return stripos( $title, 'Harry' ) !== false;
			} else {
				return false;
			}
		}

		/**
		 * @param String $asin
		 * @param String $region
		 */
		function getProductDetailsAndStore( $asin, $region ) {
			/* @var $wpdb WPDB */
			global $wpdb, $azlc_database, $azlc_logger;
			// check if asin already in database, if so, skip this
			$query = $wpdb->prepare( "SELECT asin FROM $azlc_database->product_table WHERE asin = %s", $asin );

			$wpdb->get_results( $query );
			if ( $wpdb->num_rows > 0 ) {
				$azlc_logger->write( "returning out of getProductDetailsAndStore because number of rows greater than 0" );

				return;
			}


			$params = array(
				"Service"       => "AWSECommerceService",
				"Operation"     => "ItemLookup",
				"ResponseGroup" => "ItemAttributes",
				"ItemId"        => $asin,
				"IdType"        => "ASIN",
			);
			$url    = aws_signed_request( $region, $params, $this->azlkch_options['AWSAccessKeyId'], $this->azlkch_options['AWSSecretKey'],
				$this->azlkch_options['associate_tag'], '2011-08-01' );

			global $azlc_logger;
			$azlc_logger->write( $url );
			$response = wp_remote_get( $url );

			if ( is_wp_error( $response ) ) {
				$error_string = $response->get_error_message();

				$azlc_logger->write(
					'<div id="message" class="error"><p>' . $error_string . '</p>
            <P>' . $url . '</P>
            <P>The Region: ' . esc_html( $region ) . '</P>'
					. '<pre>' . print_r( $this->azlkch_options ) . '</pre>
            </div>' );
			} else {
				$azlc_logger->write( "did not get any erro" );
			}

			$body = wp_remote_retrieve_body( $response );
			$xml  = simplexml_load_string( $body );

			$title        = isset( $xml->Items->Item->ItemAttributes->Title ) ? (String) ( $xml->Items->Item->ItemAttributes->Title ) : null;
			$productGroup = isset( $xml->Items->Item->ItemAttributes->ProductGroup ) ? (String) ( $xml->Items->Item->ItemAttributes->ProductGroup ) : null;

			$res = $wpdb->insert(
				$azlc_database->product_table,
				array(
					'asin'          => $asin,
					'title'         => $title,
					'product_group' => $productGroup,
					'region'        => $region
				) );
			$azlc_logger->write( "The database result was: " . $res );

			$azlc_logger->write( $wpdb->last_query );

		}

		/**
		 * @param $asin
		 * @param $region
		 */
		function getCurrentPricesAndStore( $asin, $region ) {

			global $azlc_logger;
			$azlc_logger->write( "In getCurrentPricesAndStore... with this asin: " . esc_html( $asin ) . " and this region " . $region );


			// clean table first, if necessary
			AZLC_Utility::clean_data_table( $asin );

			$params = array(
				"Service"       => "AWSECommerceService",
				"Operation"     => "ItemLookup",
				"ResponseGroup" => "OfferSummary",
				"ItemId"        => $asin,
				"IdType"        => "ASIN",
			);

			$url = aws_signed_request( $region, $params, $this->azlkch_options['AWSAccessKeyId'], $this->azlkch_options['AWSSecretKey'],
				$this->azlkch_options['associate_tag'], '2011-08-01' );

			$azlc_logger->write( "url: " . $url );

			$response = wp_remote_get( $url );

			if ( is_wp_error( $response ) ) {
				$error_string = $response->get_error_message();
				$azlc_logger->write( "error: " . $error_string );
			}

			$body = wp_remote_retrieve_body( $response );
			$xml  = simplexml_load_string( $body );

			$data         = array();
			$data['asin'] = $asin;
			if ( $this->valid_request( $xml ) ) {

				$data['TotalNew']         = isset( $xml->Items->Item->OfferSummary->TotalNew ) ? (String) ( $xml->Items->Item->OfferSummary->TotalNew ) : null;
				$data['TotalUsed']        = isset( $xml->Items->Item->OfferSummary->TotalUsed ) ? (String) ( $xml->Items->Item->OfferSummary->TotalUsed ) : null;
				$data['TotalCollectible'] = isset( $xml->Items->Item->OfferSummary->TotalCollectible ) ? (String) ( $xml->Items->Item->OfferSummary->TotalCollectible ) : null;
				$data['TotalRefurbished'] = isset( $xml->Items->Item->OfferSummary->TotalRefurbished ) ? (String) ( $xml->Items->Item->OfferSummary->TotalRefurbished ) : null;
				$data['LowestUsedPrice']  = isset( $xml->Items->Item->OfferSummary->LowestUsedPrice->Amount ) ? (int) ( $xml->Items->Item->OfferSummary->LowestUsedPrice->Amount ) : null;
				//TODO add to database this field
				$data['LowestRefurbishedPrice'] = isset( $xml->Items->Item->OfferSummary->LowestRefurbishedPrice->Amount ) ? (int) ( $xml->Items->Item->OfferSummary->LowestRefurbishedPrice->Amount ) : null;
				$data['LowestNewPrice']         = isset( $xml->Items->Item->OfferSummary->LowestNewPrice->Amount ) ? (int) ( $xml->Items->Item->OfferSummary->LowestNewPrice->Amount ) : null;
				$data['LowestCollectiblePrice'] = isset( $xml->Items->Item->OfferSummary->LowestCollectiblePrice->Amount ) ? (int) ( $xml->Items->Item->OfferSummary->LowestCollectiblePrice->Amount ) : null;
				$data['error_code']             = isset( $xml->Items->Errors->Error->Code ) ? (string) ( $xml->Items->Errors->Error->Code ) : null;
				$data['error_message']          = isset( $xml->Items->Errors->Error->Message ) ? (string) ( $xml->Items->Errors->Error->Message ) : null;
				global $wpdb, $azlc_database;


				// **** EXTRA WORK ON ASINs that APPEAR OUT OF STOCK ******//
				// if item is out of stock, check to see if this is an abstract variations ASIN
				// this will save us from false positives
				//  http://docs.aws.amazon.com/AWSECommerceService/latest/DG/RG_VariationSummary.html
				// A variation is a child ASIN. The parent ASIN is an abstraction of the children items. For example, a shirt is a parent ASIN and parent ASINs cannot be sold.
				// This check should be done with every lookup because even abstract ASINs can become invalid/broken links

				if ( $data['TotalNew'] == 0 && $data['TotalUsed'] == 0 && $data['TotalRefurbished'] == 0 && $data['TotalCollectible'] == 0 ) {

					//todo:option  change this to the option of minimum time to sleep between amazon requests
					sleep( 1 );
					$params = array(
						"Service"       => "AWSECommerceService",
						"Operation"     => "ItemLookup",
						"ResponseGroup" => "VariationSummary",
						"ItemId"        => $asin,
						"IdType"        => "ASIN",
					);

					$url = aws_signed_request( $region, $params, $this->azlkch_options['AWSAccessKeyId'], $this->azlkch_options['AWSSecretKey'],
						$this->azlkch_options['associate_tag'], '2011-08-01' );

					$response = wp_remote_get( $url );

					if ( is_wp_error( $response ) ) {
						$error_string = $response->get_error_message();
						$azlc_logger->write( "error: " . $error_string );
					}

					$body = wp_remote_retrieve_body( $response );
					$xml  = simplexml_load_string( $body );


					if ( $this->valid_request( $xml ) ) {
						global $azlc_logger;
						$azlc_logger->write( "We are checking the variationsummary" );
						$variation_low_price = isset( $xml->Items->Item->VariationSummary->LowestPrice->Amount ) ? (int) ( $xml->Items->Item->VariationSummary->LowestPrice->Amount ) : 0;
					} else {
						$variation_low_price = 0;
					}
					if ( $variation_low_price > 0 ) {
						//YES, this is an abstract ASIN for a variation page!
						$data['abstract'] = 1;
						/* @var $wpdb WPDB */
						global $wpdb;
						$wpdb->update( $azlc_database->product_table, array( 'abstract' => 1 ), array( 'asin' => $asin ) );
					} else {
						/* @var $wpdb WPDB */
						global $wpdb;
						//we should record that we checked and this is NOT a valid abstract ASIN
						$wpdb->update( $azlc_database->product_table, array( 'abstract' => 0 ), array( 'asin' => $asin ) );
					}

				}

				$data['stock_status'] = AZLC_Utility::fuzzy_stock_status( $data );


				$wpdb->insert(
					$azlc_database->product_data_table,
					array(
						'asin'                   => $data['asin'],
						'TotalNew'               => $data['TotalNew'],
						'TotalUsed'              => $data['TotalUsed'],
						'TotalCollectible'       => $data['TotalCollectible'],
						'TotalRefurbished'       => $data['TotalRefurbished'],
						'LowestUsedPrice'        => $data['LowestUsedPrice'],
						'LowestCollectiblePrice' => $data['LowestCollectiblePrice'],
						'LowestNewPrice'         => $data['LowestNewPrice'],
						'LowestRefurbishedPrice' => $data['LowestRefurbishedPrice'],
						'error_code'             => $data['error_code'],
						'error_message'          => $data['error_message'],
						'time_of_retrieval'      => current_time( 'mysql' ),
						'stock_status'           => $data['stock_status']
					) );

				$azlc_logger->write( "the last query : " . $wpdb->last_query );


			} else {
				$azlc_logger->write( "invalid request" );
			}

		}

		function valid_request( $xml ) {
			if ( ! isset( $xml->Items->Request->IsValid ) ) {
				return false;
			}
			if ( (String) $xml->Items->Request->IsValid === 'True' ) {
				return true;
			} else {
				return false;
			}
		}

		/**
		 * @param string
		 *
		 * @return boolean
		 */
		function isProductinDatabase( $asin ) {
			/** @var $wpdb WPDB */
			global $wpdb, $azlc_database;
			$query = $wpdb->prepare( "SELECT title FROM $azlc_database->product_table WHERE asin = %s", $asin );

			return ! empty( $wpdb->get_results( $query ) );
		}


		/**
		 * @param array $object The Array of Results Returned from the Database
		 * @param string $context The name of the calling function or other context description
		 */
		function checkdatabaseresult( $object, $context = '' ) {
			global $azlc_logger, $wpdb;
			if ( $object == null ) {
				$azlc_logger->write( $context . ": Database Result Object was NULL, Last WPDB error message: " . $wpdb->last_error );
				$azlc_logger->write( $context . " Last sql: " . $wpdb->last_query );
			} elseif ( empty( $object ) ) {
				$azlc_logger->write( $context . ": Database Result was EMPTY, Last WPDB error message: " . $wpdb->last_error );
			} else {
				$azlc_logger->write( $context . ": Received an array of results with the following lenth: " . count( $object ) );

			}
		}


		public function already_parse( $post_ID ) {
			/* @var $wpdb WPDB */
			global $wpdb, $azlc_database;
			$query = $wpdb->prepare( "SELECT id FROM $azlc_database->post_status_table WHERE post_id = %d AND completed = 1", $post_ID );
			$wpdb->get_results( $query );

			return $wpdb->num_rows > 0;
		}

		// TODO HERE

		public function parse_single_post( $post_ID, $reparse = false, $relookup = 0 ) {
			// if post is already parsed, return asins and regions from database, no need to reparse
			if ( ! $reparse ) {
				if ( $this->already_parse( $post_ID ) ) {
					global $azlc_logger, $azlc_database;
					$azlc_logger->write( "post already parsed, returning with asins already in database" );
					/* @var $wpdb WPDB */
					global $wpdb;
					$query          = $wpdb->prepare( "SELECT asin, region FROM $azlc_database->link_instances_table WHERE post_id = %d", $post_ID );
					$count          = 0;
					$asins          = $wpdb->get_results( $query );
					$data_to_return = array();
					foreach ( $asins as $key => $value ) {

						// if relookup=0 then check to see if asin has recently been looked up
						// if its been recently looked up, skip this iteration
						// and continue to next one
						if ( $relookup == 0 ) {
							global $azlc_logger;
							$azlc_logger->write( "1 Already looked up " + esc_html( $value->asin ) );
							if ( $this->recently_lookedup( $value->asin ) ) {
								continue;
							}
						}

						$count ++;
						$x                    = "link" . $count;
						$data_to_return[ $x ] = array( "asin" => $value->asin, "region" => $value->region );
					}
					$data_to_return['count'] = $count;

					return $data_to_return;
				}
			}
			$data = array();
			global $azlc_logger;
			$azlc_logger->write( "in parse_single_post and the post id is: " . esc_html( $post_ID ) );
			/* @var $wpdb WPDB */
			global $wpdb, $azlc_database;
			$wpdb->insert(
				$azlc_database->post_status_table,
				array(
					'post_id'      => $post_ID,
					'completed'    => 0,
					'time_updated' => current_time( 'mysql' )
				) );
			$row_id = $wpdb->insert_id;

			// first, delete any entries for this post_id so that our database doesn't get duplicates
			$azlc_database->deleteLinkInstances( $post_ID );

			try {
				$content = get_post_field( 'post_content', $post_ID );

				$content = do_shortcode( $content );

				$parser = new AZLC_HTMLParser( $content );

				$data = $parser->extractLinks();
			} catch ( Exception $ex ) {
				$azlc_logger->write( "Exception" );

			}
			$data_to_return = array();
			$count          = 0;
			foreach ( $data as $d ) {

				$d["post_id"]  = $post_ID;
				$link_instance = new AZLC_LinkInstance( $d );
				$count ++;
				$x = "link" . $count;

				$link_instance->save();

				// if relookup=0 then check to see if asin has recently been looked up
				// if its been recently looked up, skip this iteration
				// and continue to next one
				if ( $relookup == 0 ) {
					if ( $this->recently_lookedup( $link_instance->asin ) ) {
						continue;
					}
				}

				$data_to_return[ $x ] = array( "asin" => $link_instance->asin, "region" => $link_instance->region );


			}

			$data_to_return['count'] = $count;
			// record finish of parse_post

			$rows_updated = $wpdb->update( $azlc_database->post_status_table, array( 'completed' => 1 ), array( 'id' => $row_id ), $format = null, $where_format = null );

			$azlc_logger->write( "rows updated for table post_status: " . $rows_updated );

			return $data_to_return;

		}


		public function reset() {
			$options       = get_option( 'azlc_plugin_options' );
			$internal_opts = get_option( 'azlc_plugin_options_internal' );
			global $wpdb, $azlc_database;
			$wpdb->query( "TRUNCATE TABLE " . $azlc_database->post_status_table );
			$internal_opts['pages_parsed'] = 0;
			$options['reset']              = 0;
			update_option( "azlc_plugin_options", $options );
			update_option( "azlc_plugin_options_internal", $internal_opts );
		}


		public function recently_lookedup( $asin ) {
			// return true if asin has been looked up within the last day
			// this helper function helps the program avoid looking up the same asins over and over
			// once price lookup per day is usually enough

			/* @var $wpdb WPDB */
			global $wpdb;
			global $azlc_database;
			$query  = $wpdb->prepare( "SELECT id FROM $azlc_database->product_data_table WHERE time_of_retrieval > now() - INTERVAL 1 DAY AND asin = %s", $asin );
			$result = $wpdb->get_results( $query );
			$this->checkdatabaseresult( $result, 'recently_lookedup' );

			return $wpdb->num_rows > 0;
		}


		public function get_products_by_post_id( $id ) {
			/* @var $wpdb WPDB */
			global $wpdb, $azlc_database;
			//todo santize $id
			$query   = $wpdb->prepare( "SELECT asin FROM $azlc_database->link_instances_table WHERE post_id = %d", $id );
			$results = $wpdb->get_results( $query, ARRAY_A );
			$asins   = array();
			foreach ( $results as $r ) {
				$asins[] = $r['asin'];
			}

			return $asins;

		}


		public function update_priority_queue() {
			// first, do housework on setting up the priority queue
			// $pids is an array of post_ids, or its empty
			$pids = get_option( 'azlc_pids', array() );
			while ( ! empty( $pids ) ) {
				$post_id = array_pop( $pids );
				// get each product featured on that post
				$asins = $this->get_products_by_post_id( $post_id );
				// check each product to see if its been looked up recently
				// if not, add the asin to the priority queu
				foreach ( $asins AS $a ) {
					if ( ! $this->recently_lookedup( $a ) ) {
						$this->add_to_priority_queue( $a );
					}
				}
			}
			update_option( 'azlc_pids', $pids );
		}

		public function get_region( $asin ) {
			/* @var $wpdb WPDB */
			global $wpdb, $azlc_database;
			$query = $wpdb->prepare( "SELECT region FROM $azlc_database->link_instances_table WHERE asin = %s LIMIT 1", $asin );

			return $wpdb->get_var( $query );
		}


		// 1) it gets a product from the link instance table
		// 2) if the product is not in the product details page
		// 3) then look up the product details and keep the row the SAME
		// 4) else, look up the price, and increment the row number
		public function lookup_next_asin() {
			/* @var $wpdb WPDB */
			global $azlc_database, $wpdb, $azlc_logger;

			// first, do housework
			$this->update_priority_queue();

			//now, check priority queue... if not empty, look up an asin from the priority queue
			$priority_queue = get_option( 'azlc_prq', array() );
			if ( ! empty( $priority_queue ) ) {
				$asin = array_pop( $priority_queue );
				update_option( 'azlc_prq', $priority_queue );
				$region = $this->get_region( $asin );
				$azlc_logger->write( "Got this asin from the priority queue: " . $asin );
			} else { // priority queue is empty so we will just look up the next asin in the links table

				$query                  = "SELECT DISTINCT asin, region FROM " . $azlc_database->link_instances_table . " ORDER BY post_id";
				$internal_options_array = get_option( 'azlc_plugin_options_internal' );
				$results                = $wpdb->get_row( $query, ARRAY_A, $internal_options_array['continual_row'] );

				if ( is_null( $results ) ) {

					//check if table is empty, if empty, exit (prevents inifinite loop)
					$count = $wpdb->get_var( "SELECT COUNT(*) FROM " . $azlc_database->link_instances_table );
					if ( $count == 0 ) {
						$azlc_logger->write( "links table empty" );

						return;
					}

					// if table isn't empty, then it must mean that we got to the end of the table
					// reset it to 0
					$azlc_logger->write( "table has data, but row was null, resetting to 0" );
					$internal_options_array['continual_row'] = 0;
					update_option( "azlc_plugin_options_internal", $internal_options_array );
					$this->lookup_next_asin();
				}

				$asin   = $results['asin'];
				$region = $results['region'];

				$azlc_logger->write( "lookup_next_asin last query: " . $wpdb->last_query );
				$azlc_logger->write( "and the last error was: " . $wpdb->last_error );

				// increment row number for next time
				$internal_options_array['continual_row'] ++;
				update_option( 'azlc_plugin_options_internal', $internal_options_array );
			}

			// check if region is unknown
			if ( empty( $region ) ) {
				// get default region
				$azlc_logger->write( "Region is empty, getting default" );
				$options = get_option( 'azlc_plugin_options', array( 'region' => 'com' ) );
				$region  = $options['region'];
			}

			// check to see if the product is in the product details table
			$query = $wpdb->prepare( "SELECT asin FROM $azlc_database->product_table WHERE asin = %s", $asin );
			$wpdb->get_results( $query );

			if ( $wpdb->num_rows == 0 ) {
				// we don't have any data about that product, lets fix that
				$this->getProductDetailsAndStore( $asin, $region );
				// this needs to be on the priority queue still because the prices haven't yet been looked up
				$this->add_to_priority_queue( $asin );
			} else {
				// we already know what the product is, get prices!
				$this->getCurrentPricesAndStore( $asin, $region );
			}

			return $asin;
		}

		public function add_to_priority_queue( $asin ) {
			$priority_queue   = get_option( 'azlc_prq', array() );
			$priority_queue[] = $asin;
			update_option( 'azlc_prq', $priority_queue );

		}

		public static function get_asins_not_looked_up( $max_number = '30', $timeframe = '7' ) {
			global $azlc_database, $wpdb;
			/* @var $wpdb WPDB */
			$query   = $wpdb->prepare( "SELECT DISTINCT asin FROM $azlc_database->link_instances_table WHERE asin NOT IN
		(SELECT asin FROM $azlc_database->product_data_table WHERE
		time_of_retrieval >= DATE_SUB(NOW(), INTERVAL %d DAY)) LIMIT %d", $timeframe, $max_number );
			$results = $wpdb->get_results( $query, ARRAY_A );
			$asins   = array();
			foreach ( $results as $r ) {
				$asins[] = $r['asin'];
			}

			return $asins;
		}

		public function finish() {
			AZLC_semaphore::unlock();
		}

	}

endif;