From 5fa1d8619176af0931b89f0d34536e528ee38ff8 Mon Sep 17 00:00:00 2001
From: 2FWAH <36737818+2FWAH@users.noreply.github.com>
Date: Fri, 21 Sep 2018 19:12:46 +0200
Subject: [PATCH] Add before, after and limit parameters to fetchThreads

---
 fbchat/client.py | 41 +++++++++++++++++++++++++++++++++++------
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/fbchat/client.py b/fbchat/client.py
index 66f02a4..95bd4e6 100644
--- a/fbchat/client.py
+++ b/fbchat/client.py
@@ -487,11 +487,15 @@ class Client(object):
         }))
         return j
 
-    def fetchThreads(self, thread_location, after=None, limit=None):
+    def fetchThreads(self, thread_location, before=None, after=None, limit=None):
         """
         Get all threads in thread_location.
+        Threads will be sorted from newest to oldest.
 
         :param thread_location: models.ThreadLocation: INBOX, PENDING, ARCHIVED or OTHER
+        :param before: Fetch only thread before this epoch (in ms) (default all threads)
+        :param after: Fetch only thread after this epoch (in ms) (default all threads)
+        :param limit: The max. amount of threads to fetch (default all threads)
         :return: :class:`models.Thread` objects
         :rtype: list
         :raises: FBchatException if request failed
@@ -500,15 +504,40 @@ class Client(object):
         threads += self.fetchThreadList(thread_location=thread_location)
         if not threads:
             return []
+
         while True:
-            lastThreadTimestamp = threads[-1].last_message_timestamp
-            candidates = self.fetchThreadList(before=lastThreadTimestamp, thread_location=thread_location)  # return at max 20 threads before lastThreadTimestamp (included)
+            # break if limit is exceeded
+            if limit and len(threads) >= limit:
+                break
+
+            last_thread_timestamp = threads[-1].last_message_timestamp
+            # fetchThreadList returns at max 20 threads before last_thread_timestamp (included)
+            candidates = self.fetchThreadList(before=last_thread_timestamp,
+                                              thread_location=thread_location
+                                              )
             if len(candidates) > 1:
                 threads += candidates[1:]
-            else:
+            else:  # End of threads
                 break
-        return threads  # from newest to oldest
-    
+
+            # FB returns a sorted list of threads
+            if (before is not None and int(last_thread_timestamp) > before) or \
+                (after is not None and int(last_thread_timestamp) < after):
+                break
+
+        # Return only threads between before and after (if set)
+        if before is not None or after is not None:
+            for t in list(threads):
+                last_message_timestamp = int(t.last_message_timestamp)
+                if (before is not None and last_message_timestamp > before) or \
+                    (after is not None and last_message_timestamp < after):
+                    threads.remove(t)
+
+        if limit and len(threads) > limit:
+            return threads[:limit]
+
+        return threads
+
     def fetchAllUsersFromThreads(self, threads):
         """
         Get all users involved in threads.