doc/lib: Add DocSearch class for creating search criteria

refs #6630

modules/doc/library/Doc/Search/DocSearch.php

@@ -0,0 +1,91 @@
+<?php
+/* Icinga Web 2 | (c) 2013-2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Module\Doc\Search;
+
+/**
+ * Search documentation for a given search string
+ */
+class DocSearch
+{
+    /**
+     * Search string
+     *
+     * @type string
+     */
+    protected $input;
+
+    /**
+     * Search criteria
+     *
+     * @type array
+     */
+    protected $search;
+
+    /**
+     * Create a new doc search from the given search string
+     *
+     * @param string $search
+     */
+    public function __construct($search)
+    {
+        $this->input = $search = (string) $search;
+        $criteria = array();
+        if (preg_match_all('/"(?P<search>[^"]*)"/', $search, $matches, PREG_SET_ORDER | PREG_OFFSET_CAPTURE)) {
+            $unquoted = '';
+            $offset = 0;
+            foreach ($matches as $match) {
+                $fullMatch = $match[0];
+                $searchMatch = $match['search'];
+                $unquoted .= substr($search, $offset, $fullMatch[1] - $offset);
+                $offset += $fullMatch[1] + strlen($fullMatch[0]);
+                if (strlen($searchMatch[0]) > 0) {
+                    $criteria[] = $searchMatch[0];
+                }
+            }
+            $search = $unquoted . substr($search, $offset);
+        }
+        $this->search = array_unique(array_merge($criteria, array_filter(explode(' ', trim($search)))));
+    }
+
+    /**
+     * Get the search criteria
+     *
+     * @return array
+     */
+    public function getCriteria()
+    {
+        return $this->search;
+    }
+
+    /**
+     * Get the search string
+     *
+     * @return string
+     */
+    public function getInput()
+    {
+        return $this->input;
+    }
+
+    /**
+     * Search in the given line
+     *
+     * @param   string  $line
+     *
+     * @return  DocSearchMatch|null
+     */
+    public function search($line)
+    {
+        $match = new DocSearchMatch();
+        $match->setLine($line);
+        foreach ($this->search as $criteria) {
+            $offset = 0;
+            while (($position = stripos($line, $criteria, $offset)) !== false) {
+                $match->appendMatch(substr($line, $position, strlen($criteria)), $position);
+                $offset = $position + 1;
+            }
+        }
+        return $match->isEmpty() ? null : $match;
+    }
+}