<?php
/*******************************************************************************
 * Copyright (c) 2019 Eclipse Foundation and others.
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *******************************************************************************/
/*
 * This file is a prototype for executing a license scan of a bill of
 * materials. The bill of materials is provided as plain text with each
 * line containing the one unit of content (i.e., library). Blank lines
 * and comment lines are skipped (comment lines start with "#" or "//").
 *
 * The id for a unit of content may be expressed as Maven coordinates of the form
 * "groupid:artifactid[:packaging]:version", as abbridged Purl coordinates of the form
 * "type/namespace/name@version", or as ClearlyDefined coordinates of the
 * form "type/source/namespace/name/version". Mixing formats is supported.
 *
 * Output is expressed as ClearlyDefined ids.
 *
 * Two sources of information are used to map ids to license information and other
 * metadata: first, the Eclipse Foundation data is consulted and then
 * the ClearlyDefined services are called. Future versions of this script
 * may consult other sources of data.
 *
 * usage example:
 *
 * curl -X POST http://localhost/projects/services/license_check.php \
 * --data-urlencode content@maven.deps
 *
 * curl -X POST http://localhost/projects/services/license_check.php \
 * -d $'content=npm/npmjs/@theia/variable-resolver/0.3.19\nnpm/npmjs/@theia/outline-view/0.3.19'
 *
 * curl -X POST "http://localhost/projects/services/license_check.php" \
 * -d "content=`mvn dependency:list -DskipTests -Dmaven.javadoc.skip=true | grep -Poh '\S+(?=:compile)' | sort | uniq`" | jsonpp | less
 *
 * yarn list | grep -Poh "(?:([^\/\s]+)\/)?([^\/\s]+)@\D*(\d+(?:\.\d+)*)" \
 * | curl -X POST "http://localhost/projects/services/license_check.php?XDEBUG_SESSION_START=ECLIPSE_DBGP" \
 * --data-urlencode content@- | jsonpp | less
 *
 * Note that this works with an instance running on localhost.
 *
 * TODO Validate that we can scale to ~4K lines
 * TODO support file upload.
 * TODO Customize license list based on project (e.g., science.* can use LGPL)
 * TODO Parameters for default type and provider.
 */

/**
 * Try to massage the content identifier into ClearlyDefined coordinates. That is,
 * for example, recognize Maven coordinates of the form <em>groupid:artifactid:version</em>, and
 * convert them into the ClearlyDefined equivalent, <em>maven:mavencentral:groupid:artifactid:version</em>.
 *
 * Answers <code>null<code> when the id is not recognized.
 *
 * @param string $id
 * @return NULL|string
 */
function normalizeId($id) {
	$matches = null;

	// Just pass through anything that's already in a ClearlyDefined coordinate form.
	if (preg_match('/([\w@\-.]+)(?:\/[\w@\-.]+){4}/', $id, $matches)) return $matches[0];

	/*
	 * Deal with Maven coordinates. There is a special case that we need to deal with
	 * because of Tycho using p2 repositories. When the coordinates start with
	 * "p2.eclipse-plugin" or "p2.eclipse-feature", we generate an id for p2/orbit.
	 */
	if (preg_match('/([\w@\-.]+):([\w@\-.]+)(?::[\w@\-.]+)?:(\d+(?:\.\d+)*)/', $id, $matches)) {
		if (preg_match('/^p2.eclipse-(?:plugin|feature)$/', $matches[1])) {
			return "p2/orbit/{$matches[1]}/{$matches[2]}/{$matches[3]}";
		}
		return "maven/mavencentral/{$matches[1]}/{$matches[2]}/{$matches[3]}";
	}
	/*
	 * Some p2 cases (org.apache.ant only, I think) provide all of the information that
	 * we need to match against Maven directly.
	 *
	 * e.g. "p2.eclipse-plugin:org.apache.ant:jar:lib/ant-jsch.jar:1.10.5.v20190526-1402"
	 * maps to "maven/mavencentral/org.apache.ant/ant-jsch/1.10.5"
	 */
	if (preg_match('/p2.eclipse-plugin:([\w@\-.]+)(?::[\w@\-.]+)?:lib\/([\w@\-.]+).jar:(\d+(?:\.\d+)*)/', $id, $matches)) {
		return "maven/mavencentral/{$matches[1]}/{$matches[2]}/{$matches[3]}";
	}

	/*
	 * Deal with pURL coordinates. These take the form "namespace/name@version",
	 * e.g., "@webassemblyjs/wast-printer@1.7.8". The namespace is optional; when
	 * absent, we use a dash ("-").
	 *
	 * I was surprised to see range qualifiers with some of the versions provided
	 * from yarn (<code>yarn list</code>). For now, we just ignore them.
	 *
	 * FIXME Sort out what to do with the range qualifiers
	 *
	 * FIXME Don't assume that values provided in pURL format are NPM.
	 */
	if (preg_match('/(?:([^\/\s]+)\/)?([^\/\s]+)@\D*(\d+(?:\.\d+)*)/', $id, $matches)) {
		$namespace = empty($matches[1]) ? '-' : $matches[1];
		return "npm/npmjs/{$namespace}/{$matches[2]}/{$matches[3]}";
	}

	return null;
}

function loadFromString($content) {
	$stream = fopen('php://memory','w+');
	fwrite($stream, $content);
	rewind($stream);

	$results = array();

	while ($line = trim(fgets($stream))) {
		if (empty($line)) break;
		if (preg_match('/$#', $line)) break;
		if (preg_match('/$\/\//', $line)) break;

		if ($id = normalizeId(trim($line))) {
			$results['unmatched'][$id] = array();
		} else {
			$results['invalid'][] = $line;
		}
	}

	fclose($stream);
	return $results;
}

function loadFromPackageLockString($content) {
	$json = json_decode($content, true);
	$results = array();
	visitPackages($json, function($id) use (&$results) {
		$results['unmatched'][$id] = array();
	});
	return $results;
}

function visitPackages($root, Callable $callback) {
	if (!isset($root['dependencies'])) return;

	foreach($root['dependencies'] as $name => $data) {
		$matches = null;
		if (preg_match('/^(.+)\/(.+)$/', $name, $matches)) {
			$namespace = $matches[1];
			$name = $matches[2];
		} else {
			$namespace = '-';
			$name = $name;
		}
		$id = "npm/npmjs/{$namespace}/{$name}/{$data['version']}";
		call_user_func($callback, $id);
		visitPackages($data, $callback);
	}
}

function matchAgainstEclipseProjects(&$results) {
	foreach(array_keys($results['unmatched']) as $id) {
		if ($parts = preg_split('/\//', $id)) {
			if (matchesEclipseNamespace($parts[2])) {
				unset($results['unmatched'][$id]);
				$results['approved'][$id] = array(
						'id' => $id,
						'license' => '',
						'status' => 'approved',
						'sourceUrl' => '',
						'definitionUrl' => '',
						'authority' => 'eclipse',
						'confidence' => 90
				);
			} elseif (preg_match('/^p2.eclipse-(?:plugin|feature)$/', $parts[2])) {
				if (preg_match('/^org\.(?:eclipse|polarsys|locationtech)/', $parts[3])) {
					unset($results['unmatched'][$id]);
					$results['approved'][$id] = array(
							'id' => $id,
							'license' => '',
							'status' => 'approved',
							'sourceUrl' => '',
							'definitionUrl' => '',
							'authority' => 'eclipse',
							'confidence' => 90
					);
				}
			}
		}
	}
}

function matchesEclipseNamespace($namespace) {
	// TODO Make this data-driven
	if (preg_match('/^eclipse\b/', $namespace)) return true;
	if (preg_match('/^org\.eclipse\b/', $namespace)) return true;
	if (preg_match('/^org\.polarsys\b/', $namespace)) return true;
	if (preg_match('/^org\.locationtech\b/', $namespace)) return true;
	if (preg_match('/^jakarta\b/', $namespace)) return true;
	if (preg_match('/^org\.aspectj/', $namespace)) return true;
	if (preg_match('/^@theia$/', $namespace)) return true;

	return false;
}

/*
 * Match against the consolidated data from Eclipse Foundation
 * sources. The consolidated data is stored in the dashboard
 * database by a script that runs periodically.
 *
 * This function modifies the parameter. As we find matches, the id
 * is removed from the "unmatched" set and the metadata that we do
 * find it added to an array by status.
 *
 * @see project-services/capture/php/import_third_party_license_data.php
 */
function matchAgainstFoundationData(&$results) {
	foreach(array_keys($results['unmatched']) as $id) {
		$where = array('id=":id"');
		$order = array('if(status="approved",0,1)');

		/*
		 * According to the IP Policy, service releases should match either a minor
		 * release or another service release at the same minor level.
		 *
		 * Map an id, expressed as Clearly Defined coordinates into a regular expression
		 * capable of matching against service releases.
		 *
		 * e.g., map "maven/mavencentral/com.github.jnr/jnr-posix/3.0.29" to
		 * "maven\/mavencentral\/com\.github\.jnr\/jnr\-posix\/3\.0\.[0-9]+"
		 *
		 * @param string $id an id in Clearly Defined format
		 * @param callable Function to call with the values.
		 */
		$matches = null;
		if (preg_match('/^((?:[^\/]+\/){4}(?:\d+\.\d+))(?:\.(\d+))?/', $id, $matches)) {
			$like = $matches[1] . '.%';
			$regexp = preg_quote($matches[1]) . '\.[0-9]+';
			$version = isset($matches[2]) ? $matches[2] : '0';
			// regexp is expensive, so test first with like and then regexp.
			// This improves performance by about five-fold.
			$where[] = "(id like '{$like}' and id regexp '{$regexp}')";
			// Order results so that the one with the service release number that's closest
			// to the one we want is at the top of the list.
			$order[] = "abs(substring_index(substring_index(id,'/',-1),'.',-1) - {$version})";
		}

		$whereClause = implode(' OR ', $where);
		$orderList = implode(', ', $order);

		// There may be multiple hits for a particular id. The query only
		// returns one row, preferring rows that represent 'approved'
		// content.
		$sql = "
			select
				id, license, status, sourceUrl, definitionUrl, authority, confidence
			from ThirdPartyLicense
			where $whereClause
			order by $orderList
			limit 1";
		$args = array(':id' => $id);

		query('dashboard', $sql, $args, function($row) use (&$results, $id) {
			$row['id'] = $id;
			unset($results['unmatched'][$id]);
			$results[$row['status']][$id] = $row;
		});
	}
}

// Everything above this line could (and probably should) be factored out.

header ("Content-type: text/csv");
header ("Content-Disposition: \"inline; filename=licenses.csv\"");

require_once (dirname ( __FILE__ ) . "/../../eclipse.org-common/system/app.class.php");
$App = new App ();

require_once dirname(__FILE__) . "/../classes/database.inc";

if ($content = @$_POST['content']) {
	$results = loadFromString($content);
} elseif ($content = @$_POST['package-lock']) {
	$results = loadFromPackageLockString($content);
} elseif ($content = @$_POST['json']) {
	$results = array('unmatched' => array_fill_keys(json_decode($content, true),array()));
}

if ($results) {
	matchAgainstEclipseProjects($results);
	matchAgainstFoundationData($results);
} else {
	$results = array();
}

echo json_encode($results);

?>