Refactor most of _postLogin into the State model

fbchat/_state.py

@@ -2,9 +2,13 @@
 from __future__ import unicode_literals
 
 import attr
+import bs4
+import re
 
 from . import _util
 
+FB_DTSG_REGEX = re.compile(r'name="fb_dtsg" value="(.*?)"')
+
 
 @attr.s(slots=True, kw_only=True)
 class State(object):
@@ -29,3 +33,21 @@ class State(object):
             "__rev": self._revision,
             "fb_dtsg": self.fb_dtsg,
         }
+
+    @classmethod
+    def from_base_request(cls, content):
+        soup = bs4.BeautifulSoup(content, "html.parser")
+
+        fb_dtsg_element = soup.find("input", {"name": "fb_dtsg"})
+        if fb_dtsg_element:
+            fb_dtsg = fb_dtsg_element["value"]
+        else:
+            # Fall back to searching with a regex
+            fb_dtsg = FB_DTSG_REGEX.search(content).group(1)
+
+        revision = int(content.split('"client_revision":', 1)[1].split(",", 1)[0])
+
+        logout_h_element = soup.find("input", {"name": "h"})
+        logout_h = logout_h_element["value"] if logout_h_element else None
+
+        return cls(fb_dtsg=fb_dtsg, revision=revision, logout_h=logout_h)