Add thread pruning for threads that pass the maximum page threshhold

Each board is allowed a number of threads per page, and a maximum number
of pages (default 10 for both). If a thread falls off the last page, it
is deleted.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

board/models.py

@@ -39,21 +39,30 @@ class Board(models.Model):
     url = models.CharField(max_length=255, null=False, blank=False, unique=True)
     # Human-readable name for the board
     name = models.CharField(max_length=255, null=False, blank=False)
+    # Max pages
+    max_pages = models.IntegerField(default=10)
+    # Threads per page
+    threads_per_page = models.IntegerField(default=10)
 
     @property
     def threads(self):
         return Post.objects.filter(board=self, op=None)
 
+    @property
+    def max_threads(self):
+        return self.max_pages * self.threads_per_page
+
+    def prune_threads(self):
+        to_remove = self.threads.order_by("-last_bump")[self.max_threads :]
+        for thread in to_remove:
+            thread.delete()
+
 
 class Post(models.Model):
     # Board that this post was made on
     board = models.ForeignKey("Board", on_delete=models.CASCADE)
     # Thread that this is a part of
     op = models.ForeignKey(
-        "self", null=True, on_delete=models.CASCADE, related_name="all_replies"
-    )
-    # Post that this is replying to
-    reply = models.ForeignKey(
         "self", null=True, on_delete=models.CASCADE, related_name="replies"
     )
     # User's supplied name for this post
@@ -139,9 +148,14 @@ class Post(models.Model):
 
 @receiver(signals.post_save, sender=Post)
 def post_created(sender, instance, created, **kwargs):
-    if created and instance.op:
-        instance.op.last_bump = timezone.now()
-        instance.op.save()
+    if created:
+        if instance.op:
+            # Update the bump
+            instance.op.last_bump = timezone.now()
+            instance.op.save()
+        else:
+            # Prune threads for the board
+            instance.board.prune_threads()
 
 
 @receiver(signals.post_delete, sender=Post)

board/views.py

@@ -3,7 +3,6 @@ from django.http import Http404, HttpResponseRedirect
 from django.shortcuts import render, get_object_or_404
 from django.views.generic import DetailView
 from django.views.generic.edit import CreateView
-
 from board.models import Post, Board
 
 __all__ = ("BoardView", "PostView")
@@ -29,7 +28,6 @@ class BoardView(CreateView):
     fields = ["subject", "name", "text", "image"]
     slug_field = "url"
     slug_url_kwarg = "url"
-
     template_name = "board/board_detail.html"
 
     def get_context_data(self, **kwargs):
@@ -38,13 +36,11 @@ class BoardView(CreateView):
         kwargs["board"] = board
         page = self.kwargs.get("page", 1)
 
-        # TODO - allow max number of pages to be specified per-board
-        if page not in range(1, 10 + 1):
+        if page not in range(1, board.max_pages + 1):
             raise Http404()
 
-        PER_PAGE = 10
-        start = (page - 1) * PER_PAGE
-        end = start + PER_PAGE
+        start = (page - 1) * board.threads_per_page
+        end = start + board.threads_per_page
         kwargs["threads"] = board.threads.order_by("-last_bump")[start:end]
         kwargs["page"] = page
         kwargs["max_upload_size"] = settings.MAX_UPLOAD_SIZE