From b2ef0032077fbec4ff339469d8604a5572bcf816 Mon Sep 17 00:00:00 2001
From: Arthur Milchior <Arthur@Milchior.fr>
Date: Tue, 11 Feb 2020 16:16:38 -0800
Subject: [PATCH 1/3] hook note_is_being_flushed

I created multiple add-ons which want to transform a note before it is
being saved. For example, one add-on trim it, and remove useless line
break which arrived by accident.

Another add-on want to compile LaTeX as soon as the note is done, and
warn the user if LaTeX can't be compiled.

Having a hook in pre-flush would be useful here
---
 pylib/anki/hooks.py     | 27 +++++++++++++++++++++++++++
 pylib/anki/notes.py     |  2 ++
 pylib/tools/genhooks.py |  5 +++++
 3 files changed, 34 insertions(+)

diff --git a/pylib/anki/hooks.py b/pylib/anki/hooks.py
index 5ab0f341a..1c1627401 100644
--- a/pylib/anki/hooks.py
+++ b/pylib/anki/hooks.py
@@ -18,6 +18,7 @@ import decorator
 
 import anki
 from anki.cards import Card
+from anki.notes import Note
 
 # New hook/filter handling
 ##############################################################################
@@ -277,6 +278,32 @@ class _NoteTypeAddedHook:
 note_type_added = _NoteTypeAddedHook()
 
 
+class _NoteWillFlushHook:
+    """Allow to change a note before it is added/updated in the database."""
+
+    _hooks: List[Callable[[Note], None]] = []
+
+    def append(self, cb: Callable[[Note], None]) -> None:
+        """(note: Note)"""
+        self._hooks.append(cb)
+
+    def remove(self, cb: Callable[[Note], None]) -> None:
+        if cb in self._hooks:
+            self._hooks.remove(cb)
+
+    def __call__(self, note: Note) -> None:
+        for hook in self._hooks:
+            try:
+                hook(note)
+            except:
+                # if the hook fails, remove it
+                self._hooks.remove(hook)
+                raise
+
+
+note_will_flush = _NoteWillFlushHook()
+
+
 class _NotesWillBeDeletedHook:
     _hooks: List[Callable[["anki.storage._Collection", List[int]], None]] = []
 
diff --git a/pylib/anki/notes.py b/pylib/anki/notes.py
index 266733d64..6d6cf4174 100644
--- a/pylib/anki/notes.py
+++ b/pylib/anki/notes.py
@@ -6,6 +6,7 @@ from __future__ import annotations
 from typing import Any, Dict, List, Optional, Tuple
 
 import anki  # pylint: disable=unused-import
+from anki import hooks
 from anki.models import Field, NoteType
 from anki.utils import (
     fieldChecksum,
@@ -202,6 +203,7 @@ insert or replace into notes values (?,?,?,?,?,?,?,?,?,?,?)""",
     ##################################################
 
     def _preFlush(self) -> None:
+        hooks.note_will_flush(self)
         # have we been added yet?
         self.newlyAdded = not self.col.db.scalar(
             "select 1 from cards where nid = ?", self.id
diff --git a/pylib/tools/genhooks.py b/pylib/tools/genhooks.py
index df83e73fa..0923dba6b 100644
--- a/pylib/tools/genhooks.py
+++ b/pylib/tools/genhooks.py
@@ -67,6 +67,11 @@ hooks = [
         Your add-on can check filter_name to decide whether it should modify
         field_text or not before returning it.""",
     ),
+    Hook(
+        name="note_will_flush",
+        args=["note: Note"],
+        doc="Allow to change a note before it is added/updated in the database.",
+    ),
     Hook(
         name="card_did_render",
         args=[

From 81daad878e819ae59df0ac5f7226004c71582d8e Mon Sep 17 00:00:00 2001
From: Arthur Milchior <Arthur@Milchior.fr>
Date: Tue, 11 Feb 2020 16:20:37 -0800
Subject: [PATCH 2/3] Factorizing card's flush

---
 pylib/anki/cards.py | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/pylib/anki/cards.py b/pylib/anki/cards.py
index 2de6960e5..a31c0fb81 100644
--- a/pylib/anki/cards.py
+++ b/pylib/anki/cards.py
@@ -84,7 +84,7 @@ class Card:
         self._render_output = None
         self._note = None
 
-    def flush(self) -> None:
+    def _preFlush(self) -> none:
         self.mod = intTime()
         self.usn = self.col.usn()
         # bug check
@@ -95,6 +95,9 @@ class Card:
         ):
             hooks.card_odue_was_invalid()
         assert self.due < 4294967296
+
+    def flush(self) -> None:
+        self._preFlush()
         self.col.db.execute(
             """
 insert or replace into cards values
@@ -121,16 +124,8 @@ insert or replace into cards values
         self.col.log(self)
 
     def flushSched(self) -> None:
-        self.mod = intTime()
-        self.usn = self.col.usn()
+        self._preFlush()
         # bug checks
-        if (
-            self.queue == QUEUE_TYPE_REV
-            and self.odue
-            and not self.col.decks.isDyn(self.did)
-        ):
-            hooks.card_odue_was_invalid()
-        assert self.due < 4294967296
         self.col.db.execute(
             """update cards set
 mod=?, usn=?, type=?, queue=?, due=?, ivl=?, factor=?, reps=?,

From fcfa78bba35e0510747e0f28923bc5fd557573f8 Mon Sep 17 00:00:00 2001
From: Arthur Milchior <Arthur@Milchior.fr>
Date: Tue, 11 Feb 2020 16:23:20 -0800
Subject: [PATCH 3/3] Hook card_is_being_flushed

It often arrives that I want to know when a card is going to be
flushed and in this case change it.

This could be the case if I want to change the scheduler without
implementing a whole scheduler. It simply reads the card history and
change interval and due date.

It's also the case for the "'trigger -> action' rules", which apply
some coded actions when some event occurs. E.g. suspend/unsuspend a
sibling when card become mature/is forgotten.
---
 pylib/anki/cards.py     |  3 ++-
 pylib/anki/hooks.py     | 26 ++++++++++++++++++++++++++
 pylib/tools/genhooks.py |  5 +++++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/pylib/anki/cards.py b/pylib/anki/cards.py
index a31c0fb81..480986ebc 100644
--- a/pylib/anki/cards.py
+++ b/pylib/anki/cards.py
@@ -84,7 +84,8 @@ class Card:
         self._render_output = None
         self._note = None
 
-    def _preFlush(self) -> none:
+    def _preFlush(self) -> None:
+        hooks.card_will_flush(self)
         self.mod = intTime()
         self.usn = self.col.usn()
         # bug check
diff --git a/pylib/anki/hooks.py b/pylib/anki/hooks.py
index 1c1627401..d46465e4e 100644
--- a/pylib/anki/hooks.py
+++ b/pylib/anki/hooks.py
@@ -134,6 +134,32 @@ class _CardOdueWasInvalidHook:
 card_odue_was_invalid = _CardOdueWasInvalidHook()
 
 
+class _CardWillFlushHook:
+    """Allow to change a card before it is added/updated in the database."""
+
+    _hooks: List[Callable[[Card], None]] = []
+
+    def append(self, cb: Callable[[Card], None]) -> None:
+        """(card: Card)"""
+        self._hooks.append(cb)
+
+    def remove(self, cb: Callable[[Card], None]) -> None:
+        if cb in self._hooks:
+            self._hooks.remove(cb)
+
+    def __call__(self, card: Card) -> None:
+        for hook in self._hooks:
+            try:
+                hook(card)
+            except:
+                # if the hook fails, remove it
+                self._hooks.remove(hook)
+                raise
+
+
+card_will_flush = _CardWillFlushHook()
+
+
 class _DeckAddedHook:
     _hooks: List[Callable[[Dict[str, Any]], None]] = []
 
diff --git a/pylib/tools/genhooks.py b/pylib/tools/genhooks.py
index 0923dba6b..9e124be77 100644
--- a/pylib/tools/genhooks.py
+++ b/pylib/tools/genhooks.py
@@ -72,6 +72,11 @@ hooks = [
         args=["note: Note"],
         doc="Allow to change a note before it is added/updated in the database.",
     ),
+    Hook(
+        name="card_will_flush",
+        args=["card: Card"],
+        doc="Allow to change a card before it is added/updated in the database.",
+    ),
     Hook(
         name="card_did_render",
         args=[