[IMP] link_tracker: use existing title from url method

Prevent duplicated code by changing the url
title retrieving method to use the existing one
from mail.

As the title retrieving method is now limited to
the <head> of the html, remove the unnecessary
check on the content max size which was previously
added to prevent memory limit from exceeding
when the html content was too big.

Task-3234864

Part-of: odoo/odoo#122087

addons/link_tracker/models/link_tracker.py

@@ -11,8 +11,7 @@ from werkzeug import urls
 from odoo import tools, models, fields, api, _
 from odoo.exceptions import UserError
 from odoo.osv import expression
-
-URL_MAX_SIZE = 10 * 1024 * 1024
+from odoo.addons.mail.tools import link_preview
 
 
 class LinkTracker(models.Model):
@@ -112,22 +111,10 @@ class LinkTracker(models.Model):
     @api.model
     @api.depends('url')
     def _get_title_from_url(self, url):
-        try:
-            head = requests.head(url, allow_redirects=True, timeout=5)
-            if (
-                    int(head.headers.get('Content-Length', 0)) > URL_MAX_SIZE
-                    or
-                    'text/html' not in head.headers.get('Content-Type', 'text/html')
-            ):
-                return url
-            # HTML parser can work with a part of page, so ask server to limit downloading to 50 KB
-            page = requests.get(url, timeout=5, headers={"range": "bytes=0-50000"})
-            p = html.fromstring(page.text.encode('utf-8'), parser=html.HTMLParser(encoding='utf-8'))
-            title = p.find('.//title').text
-        except:
-            title = url
-
-        return title
+        preview = link_preview.get_link_preview_from_url(url)
+        if preview and preview.get('og_title'):
+            return preview['og_title']
+        return url
 
     @api.constrains('url', 'campaign_id', 'medium_id', 'source_id')
     def _check_unicity(self):