<?php
/**
 * Locum is a software library that abstracts ILS functionality into a
 * catalog discovery layer for use with such things as bolt-on OPACs like
 * SOPAC.
 * @package Locum
 * @author John Blyberg
 */

require_once('locum.php');

/**
 * This class is the server component of Locum.  It is separated from the client piece because the functionality
 * in this class should never need to be used in any front-end pieces.  This class does all the harvesting and
 * data preparation.
 */
class locum_server extends locum {

	/**
	 * This function initiates the harvest of bib records from the catalog.
	 *
	 * @param int $start Bib number to start with
	 * @param int $end Bib number to end with
	 * @param boolean $quiet quietly harvest or not.  Default: TRUE
	 */
	public function harvest_bibs($start, $end, $quiet = TRUE) {
		
		if ($start > $end) { return 0; }

		$num_children = $this->locum_config[harvest_config][max_children];
		$num_to_process = $end - $start;
		$increment = ceil($num_to_process / $num_children);
		if (extension_loaded('pcntl') && $this->locum_config[harvest_config][harvest_with_children] && ($num_to_process >= (2 * $num_children))) {
			for ($i = 0; $i < $num_children; ++$i) {
				$end = $start + ($increment - 1);
				$new_start = $end + 1;
	
				$pid = pcntl_fork();
				if ($pid != -1) {
					if ($pid) {
						parent::putlog("Spawning child harvester to scan records $start - $end. PID is $pid ..");
					} else {
						sleep(1);
						++$i;
						if ($i == $num_children) { $end++; }
						$result = self::import_bibs($start, $end);
						parent::putlog("Child process complete.  Scanned records $start - $end.  Imported $result[imported] reords and skipped $result[skipped] ..", 2);
						exit($i);
					}
				} else {
					parent::putlog("Unable to spawn harvester: ($i)", 5);
				}
				$start = $new_start;
			}
			if ($pid) {
				while ($i > 0) {
					pcntl_waitpid(-1, &$status);
					$val = pcntl_wexitstatus($status);
					--$i;
					}
				parent::putlog("Harvest complete!", 3);
			}
		} else {
			$result = self::import_bibs($start, $end);
		}
	}

	/**
	 * Does the actual import of bib records.  Called by the harvester.
	 * It uses start and end parameters because this function can potentially be called by a
	 * child process.
	 *
	 * @param int $start Bib number to start with
	 * @param int $end Bib number to end with
	 * @return array Array of information about the bibs imported
	 */
	public function import_bibs($start, $end) {

		$db =& MDB2::connect($this->dsn);

		$process_report[skipped] = 0;
		$process_report[imported] = 0;

		for ($i = $start; $i <= $end; $i++) {
			$bib = $this->locum_cntl->scrape_bib($i);

			if ($bib == FALSE) {
				$process_report[skipped]++;
			} else {
				$subj = array_pop($bib);
				$valid_vals = array('bnum', 'author', 'addl_author', 'title', 'title_medium', 'edition', 'series', 'callnum', 'pub_info', 'pub_year', 'stdnum', 'lccn', 'descr', 'notes', 'subjects_ser', 'lang', 'loc_code', 'mat_code', 'cover_img', 'bib_created', 'bib_lastupdate', 'bib_prevupdate', 'bib_revs');
				foreach ($bib as $bkey => $bval) {
					if (in_array($bkey, $valid_vals)) { $bib_values[$bkey] = $bval; }
				}
				$bib_values[subjects_ser] = serialize($subj);
				$types = array('integer', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'date', 'date', 'date', 'integer');

				$sql_prep = $db->prepare('INSERT INTO locum_bib_items VALUES (:bnum, :author, :addl_author, :title, :title_medium, :edition, :series, :callnum, :pub_info, :pub_year, :stdnum, :lccn, :descr, :notes, :subjects_ser, :lang, :loc_code, :mat_code, :cover_img, NOW(), :bib_created, :bib_lastupdate, :bib_prevupdate, :bib_revs, \'1\')');
				$affrows = $sql_prep->execute($bib_values);
				$sql_prep->free();

				if (is_array($subj) && count($subj)) {
					foreach ($subj as $subj_heading) {
						$insert_data = array($bib[bnum], $subj_heading);
						$types = array('integer', 'text');
						$sql_prep = $db->prepare('INSERT INTO locum_bib_items_subject VALUES (?, ?)', $types, MDB2_PREPARE_MANIP);
						$affrows = $sql_prep->execute($insert_data);
						$sql_prep->free();
					}
				}
				$process_report[imported]++;
			}
		}
		$db->disconnect();
		return $process_report;
	}

	/**
	 * Scans existing imported bibs for changes or weeds and makes the appropriate changes.
	 * 
	 * @param boolean $quiet Run this function silently.  Default: TRUE
	 */
	public function verify_bibs($quiet = TRUE) {

		parent::putlog("Collecting current data keys ..");
		$db =& MDB2::connect($this->dsn);
		$sql = 'SELECT bnum, bib_lastupdate FROM locum_facet_heap';
		$init_result =& $db->query($sql);
		$init_bib_arr = $init_result->fetchAll(MDB2_FETCHMODE_ASSOC);
		$num_children = $this->locum_config[harvest_config][max_children];
		$num_to_process = count($init_bib_arr);
		foreach ($init_bib_arr as $init_bib_arr_vals) {
			$bib_arr[$init_bib_arr_vals[bnum]] = $init_bib_arr_vals[bib_lastupdate];
		}
		$db->disconnect();
		parent::putlog("Finished collecting data keys.");

		if (extension_loaded('pcntl') && $this->locum_config[harvest_config][harvest_with_children] && ($num_to_process >= (2 * $num_children))) {
			
			$increment = ceil($num_to_process / $num_children);

			$split_offset = 0;
			for ($i = 0; $i < $num_children; ++$i) {
				$end = $start + ($increment - 1);
				$new_start = $end + 1;
	
				$pid = pcntl_fork();
				if ($pid != -1) {
					if ($pid) {
						parent::putlog("Spawning child harvester to verify records. PID is $pid ..");
					} else {
						sleep(1);
						++$i;
						if ($i == $num_children) { $end++; }
						$bib_arr_sliced = array_slice($bib_arr, $split_offset, $increment, TRUE);
						$num_bibs = count($bib_arr_sliced);
						$tmp = self::update_bib($bib_arr_sliced);
						$updated = $tmp[updated];
						$retired = $tmp[retired];
						parent::putlog("Child process complete.  Checked $num_bibs records, updated $updated records, retired $retired records.", 2);
						exit($i);
					}
				} else {
					parent::putlog("Unable to spawn harvester: ($i)", 5);
				}
				$start = $new_start;
				$split_offset = $split_offset + $increment;
			}
			if ($pid) {
				while ($i > 0) {
					pcntl_waitpid(-1, &$status);
					$val = pcntl_wexitstatus($status);
					--$i;
					}
				parent::putlog("Verification complete!", 3);
			}
		} else {
			// TODO - Bib verification for those poor saps w/o pcntl
		}
	}

	/**
	 * Does the actual update of the bib record if something has changed.
	 * This function is called by verify_bibs()
	 *
	 * @param array $bib_arr Array of bibs like: key => val is bnum => last update date
	 * @return array Array of # updated and # retired
	 */
	public function update_bib($bib_arr) {

		$db = MDB2::connect($this->dsn);
		$updated = 0;
		$retired = 0;

		foreach ($bib_arr as $bnum => $init_bib_date) {

			$bib = $this->locum_cntl->scrape_bib($bnum, TRUE);


			if ($bib == FALSE) {
				// TODO add a verification of weed in here somehow
				$sql_prep =& $db->prepare('UPDATE locum_bib_items SET active = ? WHERE bnum = ?', array('text', 'integer'));
				$sql_prep->execute(array('0', $bnum));
				$sql_prep =& $db->prepare('DELETE FROM locum_bib_items_subject WHERE bnum = ?', array('integer'));
				$sql_prep->execute(array($bnum));
				$sql_prep->free();
				$retired++;
			} else if ($bib[bnum] && $bib[bib_lastupdate] != $init_bib_date) {
				$subj = array_pop($bib);
				$valid_vals = array('bib_created', 'bib_lastupdate', 'bib_prevupdate', 'bib_revs', 'lang', 'loc_code', 'mat_code', 'author', 'addl_author', 'title', 'title_medium', 'edition', 'series', 'callnum', 'pub_info', 'pub_year', 'stdnum', 'lccn', 'descr', 'notes', 'bnum');
				foreach ($bib as $bkey => $bval) {
					if (in_array($bkey, $valid_vals)) { $bib_values[$bkey] = $bval; }
				}
				
				$bib_values[subjects_ser] = serialize($subj);
			
				$types = array('date', 'date', 'date', 'integer', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'integer', 'text', 'text', 'text', 'text', 'text', 'integer');
		
				$setlist = 
					"bib_created = :bib_created, " .
					"bib_lastupdate = :bib_lastupdate, " .
					"bib_prevupdate = :bib_prevupdate, " .
					"bib_revs = :bib_revs, " .
					"lang = :lang, " .
					"loc_code = :loc_code, " .
					"mat_code = :mat_code, " .
					"author = :author, " .
					"addl_author = :addl_author, " .
					"title = :title, " .
					"title_medium = :title_medium, " .
					"edition = :edition, " .
					"series = :series, " .
					"callnum = :callnum, " .
					"pub_info = :pub_info, " .
					"pub_year = :pub_year, " .
					"stdnum = :stdnum, " .
					"lccn = :lccn, " .
					"descr = :descr, " .
					"notes = :notes, " .
					"subjects = :subjects_ser, " .
					"modified = NOW()";
			
				$sql_prep =& $db->prepare('UPDATE locum_bib_items SET ' . $setlist . ' WHERE bnum = :bnum', $types, MDB2_PREPARE_MANIP);
				$res = $sql_prep->execute($bib_values);
				$sql_prep =& $db->prepare('DELETE FROM locum_bib_items_subject WHERE bnum = ?', array('integer'));
				$sql_prep->execute(array($bnum));
				$sql_prep->free();
			
				if (is_array($subj) && count($subj)) {
					foreach ($subj as $subj_heading) {
						$insert_data = array($bnum, $subj_heading);
						$types = array('integer', 'text');
						$sql_prep =& $db->prepare('INSERT INTO locum_bib_items_subject VALUES (?, ?)', $types, MDB2_PREPARE_MANIP);
						$affrows = $sql_prep->execute($insert_data);
						$sql_prep->free();
					}
				}
				parent::putlog("Updated record # $bnum", 2, TRUE);
				$updated++;
			}
		}
		$db->disconnect();
		return array('retired' => $retired, 'updated' => $updated);
	}

	/**
	 * Scans for newly cataloged bib records.
	 * Uses the ini "harvest_reach" param to determine how far forward to seek.
	 */
	public function new_bib_scan() {
		$db = MDB2::connect($this->dsn);
		$sql = 'SELECT MAX(bnum) FROM locum_bib_items';
		$max_bib_result =& $db->query($sql);
		$max_bib = $max_bib_result->fetchOne();
		$next_bib = $max_bib + 1;
		$last_bib = $next_bib + $this->locum_config[harvest_config][harvest_reach];
		$db->disconnect();
		self::harvest_bibs($next_bib, $last_bib);
	}
	
	/**
	 * Flushes the holds_count table and rebuilds it.  Useful for keeping popularity information
	 * up-to-date.  It's needed in this format so that the sphinx index can be rebuilt with 
	 * dortable popularity data.
	 */
	public function rebuild_holds_cache() {
		$db = MDB2::connect($this->dsn);
		$db->query('DELETE FROM locum_holds_count');
		$db->query('INSERT INTO locum_holds_count (bnum) SELECT locum_bib_items.bnum FROM locum_bib_items');

		$counts = array('week', 'month', 'year', 'total');
		$sql_week = 'SELECT bnum, COUNT(bnum) AS total FROM locum_holds_placed WHERE hold_date >= DATE_SUB(CURDATE(), INTERVAL 1 WEEK) GROUP BY bnum';
		$sql_month = 'SELECT bnum, COUNT(bnum) AS total FROM locum_holds_placed WHERE hold_date >= DATE_SUB(CURDATE(), INTERVAL 1 MONTH) GROUP BY bnum';
		$sql_year = 'SELECT bnum, COUNT(bnum) AS total FROM locum_holds_placed WHERE hold_date >= DATE_SUB(CURDATE(), INTERVAL 1 YEAR) GROUP BY bnum';
		$sql_total = 'SELECT bnum, COUNT(bnum) AS total FROM locum_holds_placed GROUP BY bnum';
		
		foreach ($counts as $count_type) {
			$dbq =& $db->query(${'sql_' . $count_type});
			$result_arr = $dbq->fetchAll(MDB2_FETCHMODE_ASSOC);
			foreach ($result_arr as $result) {
				$db->query('UPDATE locum_holds_count SET hold_count_' . $count_type . ' = ' . $result[total] . ' WHERE bnum = ' . $result[bnum]);
			}
		}
	}
	
	public function rebuild_facet_heap() {
		$db = MDB2::connect($this->dsn);
		$db->exec('DELETE FROM locum_facet_heap');
		$db->exec('INSERT INTO locum_facet_heap SELECT bnum, series, mat_code, loc_code, lang, pub_year, bib_lastupdate FROM locum_bib_items WHERE active = \'1\'');
	}

	/**
	 * Grabs the cover image URL for caching (much faster on the front-end to do it this way).
	 * Will try amazon if the ini says so.
	 *
	 * @param string $stdnum_raw - stdnum/ISBN from the bib record
	 * @return string Image URL or NULL
	 */
	public function get_cover_img($stdnum_raw) {

		// Format stdnum as best we can
		if (preg_match('/ /', $stdnum_raw)) {
			$stdnum_arr = explode(' ', $stdnum_raw);
			$stdnum = trim($stdnum_arr[0]);
		} else {
			$stdnum = trim($stdnum_raw);
		}
		$api_cfg = $this->locum_config[api_config];
		$image_url = '';
		if ($api_cfg[use_amazon_images] && $api_cfg[use_syndetic_images]) {
			if ($api_cfg[amazon_img_prio] >= $api_cfg[syndetic_img_prio]) {
				$image_url = self::get_amazon_image($stdnum, $api_cfg[amazon_access_key]);
				if (!$image_url) { $image_url = self::get_syndetic_image($stdnum, $api_cfg[syndetic_custid]); }
			} else {
				$image_url = self::get_syndetic_image($stdnum, $api_cfg[syndetic_custid]);
				if (!$image_url) { $image_url = self::get_amazon_image($stdnum, $api_cfg[amazon_access_key]); }

			}
		} else if ($api_cfg[use_amazon_images]) {
			$image_url = self::get_amazon_image($stdnum, $api_cfg[amazon_access_key]);
		} else if ($api_cfg[use_syndetic_images]) {
			$image_url = self::get_syndetic_image($stdnum, $api_cfg[syndetic_custid]);
		}
		return $image_url;
	}

	/**
	 * Used by get_cover_img to get the Amazon cover image URL.
	 * You'll need to put in your own Amazon API key into the ini.
	 *
	 * @param string $stdnum Stdnum/ISBN
	 * @param string $api_key Amazon API key - they're free.  Go git one.
	 * @return string Cover image URL
	 */
	public function get_amazon_image($stdnum, $api_key) {
		$url =  'http://webservices.amazon.com/onca/xml?Service=AWSECommerceService';
		$url.=  "&AWSAccessKeyId=$api_key";
		$url.=  "&Operation=ItemLookup&IdType=ASIN&ItemId=$stdnum";
		$url.=  '&ResponseGroup=Medium,OfferFull';

		$az_dl = @file_get_contents($url);
		list($version, $status_code, $msg) = explode(' ', $http_response_header[0], 3);
		if ($status_code == '200') {
			$az = simplexml_load_string($az_dl);
			if (is_object($az->Items)) {
				if ($az->Items->Item->MediumImage->URL) {
					$image_url = trim($az->Items->Item->MediumImage->URL);
				}
			}
		}
		return $image_url;
	}

	/**
	 * Used by get_cover_img to get the Syndetics cover image URL.
	 * You'll need to put in your own customer ID into the ini.
	 *
	 * @param string $stdnum Stdnum/ISBN
	 * @param string $cust_id Your syndetics ID - it's overpriced.  Go git one.
	 * @return string Cover image URL
	 */
	public function get_syndetic_image($stdnum, $cust_id) {
		$image_url = '';
		$url = 'http://syndetics.com/index.aspx?isbn=' . $stdnum . '/index.xml&client=' . $cust_id . '&type=xw10';
		$syn_dl = @file_get_contents($url);
		list($version, $status_code, $msg) = explode(' ', $http_response_header[0], 3);
		if (preg_match('/xml/', $syn_dl) && $status_code == '200') {
			$syn = simplexml_load_string($syn_dl);
			if ($syn->SC == 'SC.GIF') {
				$image_url = 'http://syndetics.com/hw7.pl?isbn=' . $stdnum . '/SC.GIF&client=' . $cust_id;
				$img_size = @getimagesize($image_url);
				if ($img_size[0] == 1) { $image_url = ''; }
			}
		}
		return $image_url;
	}

}