<?php

include(realpath(dirname(__FILE__) . "/config.php"));

$action = preg_replace("/[^a-zA-Z]+/", "", filter_var($_GET['action'], FILTER_SANITIZE_STRING));

switch ($action) {
	case 'resolver':
		$response = resolver();
		break;
	case 'getServices':
		$response = getServices();
		break;
	case 'updateNbResults':
		$response = updateNbResults();
		break;
	case 'getGranules':
		$response = getGranules();
		break;
	default:
		$response = ['success' => false, 'msg' => 'Unknown action: ' . $action];
		break;
}
echo json_encode($response);

function getParams($paramNames, $default=null) {
    $params = [];
	foreach($paramNames as $paramName) {
        if(array_key_exists($paramName, $_GET)) {
            $params[$paramName] = filter_var($_GET[$paramName], FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW);
        } else {
            $params[$paramName] = $default;
        }
	}
	return $params;
}

function resolver() {
	$input = filter_var($_GET['input'], FILTER_SANITIZE_URL);
	$words = preg_split("/ ?[;,] ?+/", $input);
	$lastWord = trim(array_pop($words));
	$firstsWords = implode(', ', $words);

	$resolver_url = "http://voparis-registry.obspm.fr/ssodnet/1/autocomplete?q=%22$lastWord%22";

	$response = ['success' => true, 'metaData' => ['root' => 'data', 'messageProperty' => 'msg']];
	$content = file_get_contents($resolver_url);
	if($content) {
		$result = json_decode($content, true);
		$targets = array();
		foreach($result['hits'] as $e) {
			$aliases = '<li>' . join('</li><li>', $e['aliases']) . '</li>';
			$text = (!empty($firstsWords) ? "$firstsWords, " : "") . $e['name'];
			$target = ['text' => $text, 'name' => $e['name'], 'type' => $e['type'], 'parent' => $e['parent'], 'aliases' => $aliases];
			array_push($targets, $target);
		}
		$response['data'] = $targets;
	} else {
		$response['success'] = false;
		$response['msg'] = "Resolver unreachable on $resolver_url.";
	}
	return $response;
}

function request($access_url, $query) {
#    error_log($query);
	$votMgr = new VOTableMgr;
	$params = 'FORMAT=votable&LANG=ADQL&REQUEST=doQuery';
	$url = $access_url . '/sync?' . $params . '&QUERY=' . urlencode(preg_replace('/\s+/', ' ', $query)); // remove also multiple whitespaces

	if ($votMgr->load($url)) {
		$data = $votMgr->parseStream();
	}
	$error = $votMgr->getVotableError();

	$response = ['query' => $query, 'metaData' => ['root' => 'data', 'messageProperty' => 'msg']];
	if($error) {
		$response['success'] = false;
		$response['msg'] = $error;
	} else {
		$response['success'] = true;
		$response['data'] = $data;
	}
	return $response;
}

/* Return the list of available services by querying some usual registries. */
function getServices() {
	$registriesURL = [
		//"http://vao.stsci.edu/RegTAP/TapService.aspx",
		"http://voparis-rr.obspm.fr/tap",
		"http://registry.euro-vo.org/regtap/tap",
		"http://dc.zah.uni-heidelberg.de/tap",
		"http://gavo.aip.de/tap",
		"http://reg.g-vo.org/tap",
	];
	$columns = ['short_name', 'res_title', 'ivoid', 'access_url', 'table_name', 'content_type', 'creator_seq', 'content_level', 'reference_url', 'created', 'updated'];
	$query = "SELECT DISTINCT " . implode(', ', $columns) . " FROM rr.resource
			NATURAL JOIN rr.res_schema NATURAL JOIN rr.res_table NATURAL JOIN rr.interface NATURAL JOIN rr.res_detail NATURAL JOIN rr.capability
			WHERE standard_id='ivo://ivoa.net/std/tap' AND intf_type='vs:paramhttp' AND detail_xpath='/capability/dataModel/@ivo-id'
			AND 1=ivo_nocasematch(detail_value, 'ivo://vopdc.obspm/std/EpnCore%') AND table_name LIKE '%.epn_core' ORDER BY short_name, table_name";

	$regNumber = 0;
    $r = [];
    $lastErrorMessage = '';
	for(; $regNumber < count($registriesURL) ; $regNumber++) {
		$r = request($registriesURL[$regNumber], $query);
		if($r['success']) {
			// Add several other parameters and remove AMDA
			for($j=0 ; $j<count($r['data']) ; $j++) {
				$r['data'][$j]['id'] = generateServiceId($r['data'][$j]);
				$r['data'][$j]['nb_results'] = -1;
				$r['data'][$j]['info'] = 'Please make a query.';
				if($r['data'][$j]['id'] == 'cdpp/amda/amdadb') {
					array_splice($r['data'], $j, 1);
					$j-=1;
				}
			}
			if(!is_null($lastErrorMessage)) {
				$r['msg'] = $lastErrorMessage;
			}
			break;
		} else {
			$lastErrorMesage = 'Error while requesting registry ' . $registriesURL[$regNumber] . ': ' . $r['msg'] . '.';
			error_log($lastErrorMesage);
		}
	}
	
	if(!$r['success']) {
		$r['msg'] = 'Can not access registry: ' . $lastErrorMessage;
	}
	return $r;
}

function updateNbResults() {
    $p = getParams(['url', 'tableName', 'targetNames', 'productTypes', 'timeMin', 'timeMax']);
    $select = "SELECT COUNT(*) AS nb_res, min(time_min) as time_min, max(time_max) as time_max";
    $from = "FROM " . $p['tableName'];
    $where = createFilter($p['targetNames'], $p['productTypes'], $p['timeMin'], $p['timeMax']);
	$r = request($p['url'], "$select $from $where");
	if($r['success']) {
		$r['success'] = false;
		$r['msg'] = 'The service returned a bad value, can not get the number of results.';

		if(count($r['data']) < 1) {
			error_log('updateNbResults error: Too few returned rows.');
		} else if(count($r['data']) > 1) {
			error_log('updateNbResults error: Too many returned rows.');
		} else if(!array_key_exists(0, $r['data'])) {
			error_log('updateNbResults error: cant find raw item 0');

		} else if(is_null($r['data'][0])) {
			error_log('updateNbResults error: The returned raw is null.');
		} else if(!array_key_exists("nb_res", $r['data'][0])) {
            var_dump($r['data'][0]);
			error_log('updateNbResults error: cant find nb_res value in the row: ' . json_encode($r['data'][0]));
		} else if(!is_numeric($r['data'][0]['nb_res'])) {
			error_log('updateNbResults error: The returned value is not a number.');
		} else {
			$r['success'] = true;
            $r['data'] = [
            	'nbRes' => (int)($r['data'][0]['nb_res']),
				'tMin' => JDToDate($r['data'][0]['time_min']),
				'tMax' => JDToDate($r['data'][0]['time_max'])
			];
			$r['msg'] = 'The service returned ' . ($r['data']['nbRes'] == 0 ? 'no' : $r['data']['nbRes']) . ' result' . ($r['data']['nbRes'] > 1 ? 's' : '') . ' for the given query.';
		}
	}
	return $r;
}

function getGranules() {
	$p = getParams(['url', 'tableName', 'sort', 'dir', 'targetNames', 'productTypes', 'timeMin', 'timeMax', 'start', 'limit', 'nbRes']);
    $select = "SELECT TOP " . $p['limit'] .  " *";
    $from = "FROM " . $p['tableName'];
	$where = createFilter($p['targetNames'], $p['productTypes'], $p['timeMin'], $p['timeMax']);
	$order = "ORDER BY " . (is_null($p['sort']) ? 'granule_uid ASC' : ($p['sort'] . ' ' . $p['dir']) . " OFFSET " . $p['start']);
	$response = request($p['url'], "$select $from $where $order");
	if($response['success']) {
		$visibleColumns = ['granule_gid', 'obs_id', 'dataproduct_type', 'time_min', 'time_max', 'instrument_name', 'processing_level', 'access_estsize', 'thumbnail_url', 'access_url']; // rest are hidden
		$names = ['granule_gid' => 'GID', 'dataproduct_type' => 'Type', 'processing_level' => 'Proc. lvl', 'access_estsize' => 'Size', 'access_url' => 'URL']; // default: pretty printed key name
		$renderers = ['dataproduct_type' => 'type', 'time_min' => 'date', 'time_max' => 'date', 'processing_level' => 'proc_lvl',
			'access_estsize' => 'size', 'thumbnail_url' => 'img', 'access_url' => 'link', 'access_format' => 'format']; // default: text
		$widths = ['obs_id' => 75, 'time_min' => 75, 'time_max' => 75, 'instrument_name' => 75, 'processing_level' => 60]; // default: 50

		$fields = array();
		$columns = array();
		foreach($response['data'][0] as $key => $value) {
			$fields[] = ['name' => $key, 'type' => 'string'];
			$columns[] = [
				'dataIndex' => $key,
				'text' => array_key_exists($key, $names) ? $names[$key] : ucfirst(str_replace('_', ' ', $key)),
				'width' => array_key_exists($key, $widths) ? $widths[$key] : 50,
				'hidden' => !in_array($key, $visibleColumns),
				'filterable' => true,
				// 'filter' => ['type' => 'list', 'options' => ['Image', 'Map']],
				'renderer' => 'granule.' . (array_key_exists($key, $renderers) ? $renderers[$key] : 'text')
			];
		}

		$response['total'] = (int)$p['nbRes'];
		$response['metaData']['fields'] = $fields;
		$response['metaData']['columns'] = $columns;
		$response['metaData']['metaHash'] = md5(serialize($response['metaData']));
	}
	return $response;
}

// ----- utils -----

function createFilter($targetNames, $productTypes, $timeMin, $timeMax) {
	$filter = array();
	if($targetNames) {
		array_push($filter, "target_name IN ('" . join("', '", preg_split("/ ?[;,] ?+/", $targetNames)) . "')");
	}
	if($productTypes) {
		array_push($filter, "dataproduct_type IN ('" . join("', '", explode(';', $productTypes)) . "')");
	}
	if($timeMin) {
		array_push($filter, "time_max >= " . dateToJD($timeMin));
	}
	if($timeMax) {
		array_push($filter, "time_min <= " . dateToJD($timeMax));
	}
	return (count($filter) > 0 ? 'WHERE ' . join(' AND ', $filter) : '');
}

/* Generate a unique service identifier from the service ivoid and the table name. */
function generateServiceId($service) {
	return str_replace(['ivo://', '.epn_core'], '', $service['ivoid'] . '/' . $service['table_name']);
}

function dateToJD($gregorian_date) {
	list($day, $month, $year, $hours, $minutes, $seconds) = preg_split('/[\s\/:]+/', $gregorian_date);
	return GregorianToJD($month, $day, $year) + $hours/24 + $minutes/(24*60) + $seconds/(24*60*60);
}

function JDToDate($julianDay) {
    if(is_numeric($julianDay)) {
        $jd = floatval($julianDay);
        $t = fmod($jd - floor($jd) + 0.5, 1);
        $h = floor($t*24);
        $m = floor($t*24*60 - $h*60);
        $s = floor($t*24*60*60 - $h*60*60 - $m*60);
        $d = explode('/', jdtogregorian(floor($jd)));
        $date = sprintf("%02d", $d[1]) . '/' . sprintf("%02d", $d[0]) . '/' . sprintf("%02d", $d[2]);
        $time = sprintf("%02d", $h) . ':' . sprintf("%02d", $m) . ':' . sprintf("%02d", $s);
        return $date . ' ' . $time;
    } else {
        return '-';
    }
}