feat: add getMagnetLink function

closed: #9

Author: Rhilip

README.md

@@ -161,6 +161,8 @@ $source = $torrent->getSource();
 $private = $torrent->isPrivate();  // true or false
 $torrent->setPrivate(true);
 
+$magnetLink = $torrent->getMagnetLink();
+
 // 5. Work with torrent, it will try to parse torrent ( cost time )
 $torrent->setParseValidator(function ($filename, $paths) {
     /**
@@ -200,12 +202,12 @@ $torrent
     ['https://example.com/announce'],
     ['https://example1.com/announce']
   ])
-  ->setSouce('example.com')
+  ->setSource('example.com')
   ->setPrivate(true);
 
 // Note 2: parse method may fail when get a deep invalid torrent, so it can wrapper like this
 try {
-    $torrent = TorrentFile::load($_POST['torrent']);
+    $torrent = TorrentFile::load($_POST['torrent']['tmp_name']);
     $torrent/** ->setParseValidator(function () {}) */->parse();
 } catch (ParseException $e) {
     // do something to notice user.

src/TorrentFile.php

@@ -271,7 +271,7 @@ protected function getInfoString()
 
     public function getInfoField($field, $default = null)
     {
-        return isset($this->data['info'][$field]) ? $this->data['info'][$field] : $default;
+        return $this->data['info'][$field] ?? $default;
     }
 
     public function setInfoField($field, $value)
@@ -486,6 +486,56 @@ public function setPrivate($private)
         return $private ? $this->setInfoField('private', 1) : $this->unsetInfoField('private');
     }
 
+    /**
+     * Get Torrent Magnet URI
+     * @return string
+     */
+    public function getMagnetLink($dn = true, $tr = true)
+    {
+        $urlSearchParams = [];
+
+        $infoHashV1 = $this->getInfoHashV1();
+        if ($infoHashV1) {
+            $urlSearchParams[] = 'xt=urn:btih:' . $infoHashV1;
+        }
+
+        $infoHashV2 = $this->getInfoHashV2();
+        if ($infoHashV2) {
+            $urlSearchParams[] = 'xt=url:btmh:' . '1220' . $infoHashV2;  // 1220 is magic number
+        }
+
+        if ($dn) {
+            $name = $this->getName() ?? '';
+            if ($name !== '') {
+                $urlSearchParams[] = 'dn=' . rawurlencode($name);
+            }
+        }
+
+        if ($tr) {
+            $trackers = [];
+
+            $announceList = $this->getAnnounceList();
+            if ($announceList) {
+                foreach ($announceList as $tier) {
+                    foreach ($tier as $tracker) {
+                        $trackers[] = $tracker;
+                    }
+                }
+            } else {
+                $rootTracker = $this->getAnnounce();
+                if ($rootTracker) {
+                    $trackers[] = $rootTracker;
+                }
+            }
+
+            foreach (array_unique($trackers) as $tracker) {
+                $urlSearchParams[] = 'tr=' . rawurlencode($tracker);
+            }
+        }
+
+        return 'magnet:?' . implode('&', $urlSearchParams);
+    }
+
     /**
      * Utility function to clean out keys in the data and info dictionaries that we don't need in
      * our torrent file when we go to store it in the DB or serve it up to the user (with the
@@ -667,7 +717,8 @@ public function cleanCache()
     }
 
     // Wrapper end function to avoid change the internal pointer of $path,
-    private static function arrayEnd($array) {
+    private static function arrayEnd($array)
+    {
         return end($array);
     }
 }

tests/traits/TorrentFileCommonTrait.php

@@ -202,6 +202,57 @@ public function testPrivate()
         $this->assertFalse($this->torrent->isPrivate());
     }
 
+    public function testGetMagnetLink()
+    {
+        $xtComponent = '';
+        if ($this->protocol === TorrentFile::PROTOCOL_V1) {
+            $xtComponent = 'xt=urn:btih:' . $this->infoHashs[TorrentFile::PROTOCOL_V1];
+        }
+
+        if ($this->protocol === TorrentFile::PROTOCOL_V2) {
+            $xtComponent = 'xt=url:btmh:1220' . $this->infoHashs[TorrentFile::PROTOCOL_V2];
+        }
+
+        if ($this->protocol === TorrentFile::PROTOCOL_HYBRID) {
+            $xtComponent = 'xt=urn:btih:' . $this->infoHashs[TorrentFile::PROTOCOL_V1] .
+                '&xt=url:btmh:1220' . $this->infoHashs[TorrentFile::PROTOCOL_V2];
+        }
+
+        $name = $this->fileMode === TorrentFile::FILEMODE_MULTI ? 'tname' : 'file1.dat';
+        $dnComponent = 'dn=' . rawurlencode($name);
+
+        $trComponent = 'tr=https%3A%2F%2Fexample.com%2Fannounce&tr=https%3A%2F%2Fexample1.com%2Fannounce';
+
+        $this->assertEquals('magnet:?' . implode('&', [$xtComponent, $dnComponent, $trComponent]), $this->torrent->getMagnetLink());
+        $this->assertEquals('magnet:?' . implode('&', [$xtComponent, $dnComponent]), $this->torrent->getMagnetLink(true, false));
+        $this->assertEquals('magnet:?' . implode('&', [$xtComponent, $trComponent]), $this->torrent->getMagnetLink(false, true));
+        $this->assertEquals('magnet:?' . $xtComponent, $this->torrent->getMagnetLink(false, false));
+
+        // torrent without `announce` and `announce-list` should no `&tr=` component in uri.
+        $torrentWithoutAnnounce = clone $this->torrent;
+        $torrentWithoutAnnounce->unsetRootField('announce')->unsetRootField('announce-list');
+        $this->assertEquals('magnet:?' . implode('&', [$xtComponent, $dnComponent]), $torrentWithoutAnnounce->getMagnetLink());
+
+        /**
+         * Torrent with Multitracker Metadata Extension (BEP0012)
+         * Note:
+         * 1. if the "announce-list" key is present, the client will ignore the "announce" key
+         *    and only use the URLs in "announce-list". ( From BEP )
+         *    So the "announce" field will not exist in magnet link if "announce-list" exists.
+         * 2. dupe tracker will be ignored.
+         */
+        $torrentWithEditAnnounce = clone $this->torrent;
+        $torrentWithEditAnnounce
+            ->setAnnounce('https://127.0.0.1:8888/announce')
+            ->setAnnounceList([
+                ['https://127.0.0.2:8890/announce'],
+                ['https://127.0.0.3:8891/announce', 'https://127.0.0.4:8892/announce'],
+                ['https://127.0.0.2:8890/announce']
+            ]);
+        $trComponent = 'tr=https%3A%2F%2F127.0.0.2%3A8890%2Fannounce&tr=https%3A%2F%2F127.0.0.3%3A8891%2Fannounce&tr=https%3A%2F%2F127.0.0.4%3A8892%2Fannounce';
+        $this->assertEquals('magnet:?' . implode('&', [$xtComponent, $dnComponent, $trComponent]), $torrentWithEditAnnounce->getMagnetLink());
+    }
+
     public function testGetSize()
     {
         $size = $this->fileMode === TorrentFile::FILEMODE_MULTI ? 33554432 /* 32MiB */ : 16777216 /* 16MiB */;