Basic substring searching

lib/Database.php

@@ -39,6 +39,8 @@ class Database {
     const SCHEMA_VERSION = 4;
     /** The maximum number of articles to mark in one query without chunking */
     const LIMIT_ARTICLES = 50;
+    /** The maximum number of search terms allowed; this is a hard limit */
+    const LIMIT_TERMS = 100;
     /** A map database driver short-names and their associated class names */
     const DRIVER_NAMES = [
         'sqlite3'    => \JKingWeb\Arsse\Db\SQLite3\Driver::class,
@@ -149,6 +151,35 @@ class Database {
         return $out;
     }
 
+    /** Computes basic LIKE-based text search constraints for use in a WHERE clause
+     * 
+     * Returns an indexed array containing the clause text, an array of types, and another array of values
+     * 
+     * The clause is structured such that all terms must be present across any of the columns
+     * 
+     * @param string[] $terms The terms to search for
+     * @param string[] $cols The columns to match against; these are -not- sanitized, so much -not- come directly from user input
+     */
+    protected function generateSearch(array $terms, array $cols): array {
+        $clause = [];
+        $types = [];
+        $values = [];
+        $like = $this->db->sqlToken("like");
+        foreach($terms as $term) {
+            $term = str_replace(["%", "_", "^"], ["^%", "^_", "^^"], $term);
+            $term = "%$term%";
+            $spec = [];
+            foreach ($cols as $col) {
+                $spec[] = "$col $like ? escape '^'";
+                $types[] = "str";
+                $values[] = $term;
+            }
+            $clause[] = "(".implode(" or ", $spec).")";
+        }
+        $clause = "(".implode(" and ", $clause).")";
+        return [$clause, $types, $values];
+    }
+
     /** Returns a Transaction object, which is rolled back unless explicitly committed */
     public function begin(): Db\Transaction {
         return $this->db->begin();
@@ -1160,7 +1191,7 @@ class Database {
             list($inParams, $inTypes) = $this->generateIn($context->editions, "int");
             $q->setWhere("latest_editions.edition in ($inParams)", $inTypes, $context->editions);
         } elseif ($context->articles()) {
-            // if multiple specific articles have been requested, prepare a CTE to list them and their articles
+            // if multiple specific articles have been requested, filter against the list
             if (!$context->articles) {
                 throw new Db\ExceptionInput("tooShort", ['field' => "articles", 'action' => __FUNCTION__, 'min' => 1]); // must have at least one array element
             } elseif (sizeof($context->articles) > self::LIMIT_ARTICLES) {
@@ -1221,6 +1252,15 @@ class Database {
             $comp = ($context->annotated) ? "<>" : "=";
             $q->setWhere("coalesce(arsse_marks.note,'') $comp ''");
         }
+        // filter based on search terms
+        if ($context->searchTerms()) {
+            if (!$context->searchTerms) {
+                throw new Db\ExceptionInput("tooShort", ['field' => "searchTerms", 'action' => __FUNCTION__, 'min' => 1]); // must have at least one array element
+            } elseif (sizeof($context->searchTerms) > self::LIMIT_TERMS) {
+                throw new Db\ExceptionInput("tooLong", ['field' => "searchTerms", 'action' => __FUNCTION__, 'max' => self::LIMIT_TERMS]);
+            }
+            $q->setWhere(...$this->generateSearch($context->searchTerms, ["arsse_articles.title", "arsse_articles.content"]));
+        }
         // return the query
         return $q;
     }

tests/cases/Database/SeriesArticle.php

@@ -111,9 +111,9 @@ trait SeriesArticle {
                     'modified'           => "datetime",
                 ],
                 'rows' => [
-                    [1,1,null,null,null,null,null,null,null,"","","","2000-01-01T00:00:00Z"],
+                    [1,1,null,"Title one",  null,null,null,"First article", null,"","","","2000-01-01T00:00:00Z"],
-                    [2,1,null,null,null,null,null,null,null,"","","","2010-01-01T00:00:00Z"],
+                    [2,1,null,"Title two",  null,null,null,"Second article",null,"","","","2010-01-01T00:00:00Z"],
-                    [3,2,null,null,null,null,null,null,null,"","","","2000-01-01T00:00:00Z"],
+                    [3,2,null,"Title three",null,null,null,"Third article", null,"","","","2000-01-01T00:00:00Z"],
                     [4,2,null,null,null,null,null,null,null,"","","","2010-01-01T00:00:00Z"],
                     [5,3,null,null,null,null,null,null,null,"","","","2000-01-01T00:00:00Z"],
                     [6,3,null,null,null,null,null,null,null,"","","","2010-01-01T00:00:00Z"],
@@ -494,6 +494,9 @@ trait SeriesArticle {
         // get specific starred articles
         $compareIds([1], (new Context)->articles([1,2,3])->starred(true));
         $compareIds([2,3], (new Context)->articles([1,2,3])->starred(false));
+        // get items that match search terms
+        $compareIds([1,2,3], (new Context)->searchTerms(["Article"]));
+        $compareIds([1], (new Context)->searchTerms(["one", "first"]));
     }
 
     public function testListArticlesOfAMissingFolder() {
@@ -985,4 +988,14 @@ trait SeriesArticle {
         $this->assertException("notAuthorized", "User", "ExceptionAuthz");
         Arsse::$db->articleCategoriesGet($this->user, 19);
     }
+
+    public function testSearchTooFewTerms() {
+        $this->assertException("tooShort", "Db", "ExceptionInput");
+        Arsse::$db->articleList($this->user, (new Context)->searchTerms([]));
+    }
+
+    public function testSearchTooManyTerms() {
+        $this->assertException("tooLong", "Db", "ExceptionInput");
+        Arsse::$db->articleList($this->user, (new Context)->searchTerms(range(1, 105)));
+    }
 }