https://github.com/freedomofpress/securedrop-client/issues/1634

python-statemachine.patch

diff --git a/alembic/versions/f394059c0898_add_reply_state.py b/alembic/versions/f394059c0898_add_reply_state.py
new file mode 100644
index 00000000..41fb7472
--- /dev/null
+++ b/alembic/versions/f394059c0898_add_reply_state.py
@@ -0,0 +1,28 @@
+"""add Reply.state
+
+Revision ID: f394059c0898
+Revises: 414627c04463
+Create Date: 2023-03-07 17:22:39.406291
+
+"""
+import sqlalchemy as sa
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "f394059c0898"
+down_revision = "414627c04463"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column("replies", sa.Column("state", sa.String(length=100), nullable=False))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column("replies", "state")
+    # ### end Alembic commands ###
diff --git a/requirements/requirements.in b/requirements/requirements.in
index d843971a..6250f389 100644
--- a/requirements/requirements.in
+++ b/requirements/requirements.in
@@ -14,3 +14,4 @@ six==1.11.0
 sqlalchemy==1.3.3
 urllib3>=1.26.5
 jinja2==3.0.2  # per freedomofpress/securedrop#4829953
+python-statemachine  # TODO: pin
diff --git a/securedrop_client/db.py b/securedrop_client/db.py
index 6e53de41..bcc68480 100644
--- a/securedrop_client/db.py
+++ b/securedrop_client/db.py
@@ -21,6 +21,9 @@ from sqlalchemy import (
 )
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import backref, relationship, scoped_session, sessionmaker
+from statemachine.mixins import MachineMixin
+
+from securedrop_client.statemachines import ReplyStateMachine  # noqa: F401
 
 convention = {
     "ix": "ix_%(column_0_label)s",
@@ -424,13 +427,19 @@ class File(Base):
         return False
 
 
-class Reply(Base):
+class Reply(MachineMixin, Base):
 
     __tablename__ = "replies"
     __table_args__ = (
         UniqueConstraint("source_id", "file_counter", name="uq_messages_source_id_file_counter"),
     )
 
+    state_machine_name = "ReplyStateMachine"
+    state_machine_attr = "sm"
+    state_field_name = "state"
+
+    state = Column(String(100), nullable=False)
+
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36), unique=True, nullable=False)
     source_id = Column(Integer, ForeignKey("sources.id"), nullable=False)
diff --git a/securedrop_client/logic.py b/securedrop_client/logic.py
index 5de96e3b..5ec336c1 100644
--- a/securedrop_client/logic.py
+++ b/securedrop_client/logic.py
@@ -61,6 +61,7 @@ from securedrop_client.api_jobs.uploads import (
     SendReplyJobTimeoutError,
 )
 from securedrop_client.crypto import GpgHelper
+from securedrop_client.db import Reply
 from securedrop_client.queue import ApiJobQueue
 from securedrop_client.sync import ApiSync
 from securedrop_client.utils import check_dir_permissions
@@ -378,6 +379,14 @@ class Controller(QObject):
         self.session_maker = session_maker
         self.session = session_maker()
 
+        r1 = Reply(filename="1-foo")
+        r2 = Reply(filename="2-foo")
+        print(r1.sm, r1.state)
+        print(r2.sm, r2.state)
+        r1.sm.send("send_pending")
+        print(r1.sm, r1.state)
+        print(r2.sm, r2.state)
+
         # Queue that handles running API job
         self.api_job_queue = ApiJobQueue(
             self.api, self.session_maker, self.main_queue_thread, self.file_download_queue_thread
diff --git a/securedrop_client/statemachines/__init__.py b/securedrop_client/statemachines/__init__.py
new file mode 100644
index 00000000..3b106c4a
--- /dev/null
+++ b/securedrop_client/statemachines/__init__.py
@@ -0,0 +1 @@
+from .reply import ReplyStateMachine  # noqa: F401
diff --git a/securedrop_client/statemachines/reply.py b/securedrop_client/statemachines/reply.py
new file mode 100644
index 00000000..5185abe7
--- /dev/null
+++ b/securedrop_client/statemachines/reply.py
@@ -0,0 +1,8 @@
+from statemachine import State, StateMachine
+
+
+class ReplyStateMachine(StateMachine):
+    Pending = State("Pending", initial=True)
+    SendPending = State("SendPending")
+
+    send_pending = Pending.to(SendPending)

sqlalchemy-state-machine.patch

diff --git a/alembic/versions/f394059c0898_add_reply_state.py b/alembic/versions/f394059c0898_add_reply_state.py
new file mode 100644
index 00000000..41fb7472
--- /dev/null
+++ b/alembic/versions/f394059c0898_add_reply_state.py
@@ -0,0 +1,28 @@
+"""add Reply.state
+
+Revision ID: f394059c0898
+Revises: 414627c04463
+Create Date: 2023-03-07 17:22:39.406291
+
+"""
+import sqlalchemy as sa
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "f394059c0898"
+down_revision = "414627c04463"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column("replies", sa.Column("state", sa.String(length=100), nullable=False))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column("replies", "state")
+    # ### end Alembic commands ###
diff --git a/requirements/requirements.in b/requirements/requirements.in
index d843971a..125c2339 100644
--- a/requirements/requirements.in
+++ b/requirements/requirements.in
@@ -14,3 +14,4 @@ six==1.11.0
 sqlalchemy==1.3.3
 urllib3>=1.26.5
 jinja2==3.0.2  # per freedomofpress/securedrop#4829953
+transitions  # TODO: pin
diff --git a/securedrop_client/db.py b/securedrop_client/db.py
index 6e53de41..c7ce389f 100644
--- a/securedrop_client/db.py
+++ b/securedrop_client/db.py
@@ -5,6 +5,7 @@ from pathlib import Path
 from typing import Any, Dict, List, Union  # noqa: F401
 from uuid import uuid4
 
+import sqlalchemy as sa
 from sqlalchemy import (
     Boolean,
     CheckConstraint,
@@ -22,6 +23,8 @@ from sqlalchemy import (
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import backref, relationship, scoped_session, sessionmaker
 
+from securedrop_client.statemachines import StateConfig, StateMixin
+
 convention = {
     "ix": "ix_%(column_0_label)s",
     "uq": "uq_%(table_name)s_%(column_0_name)s",
@@ -424,13 +427,28 @@ class File(Base):
         return False
 
 
-class Reply(Base):
+PENDING = "Pending"
+SEND_PENDING = "SendPending"
+
+
+class Reply(Base, StateMixin):
 
     __tablename__ = "replies"
     __table_args__ = (
         UniqueConstraint("source_id", "file_counter", name="uq_messages_source_id_file_counter"),
     )
 
+    state_config = StateConfig(
+        initial=PENDING,
+        states=[PENDING, SEND_PENDING],
+        transitions=[
+            ["send_pending", PENDING, SEND_PENDING],
+        ],
+        status_attribute="state",
+    )
+
+    state = Column(String(100), nullable=False)
+
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36), unique=True, nullable=False)
     source_id = Column(Integer, ForeignKey("sources.id"), nullable=False)
@@ -536,6 +554,9 @@ class Reply(Base):
                 usernames[seen_reply.journalist.username] = seen_reply.journalist
         return usernames
 
+sa.event.listen(Reply, "init", Reply.init_state_machine)
+sa.event.listen(Reply, "load", Reply.init_state_machine)
+
 
 class DownloadErrorCodes(Enum):
     """
diff --git a/securedrop_client/logic.py b/securedrop_client/logic.py
index 5de96e3b..c8024786 100644
--- a/securedrop_client/logic.py
+++ b/securedrop_client/logic.py
@@ -61,6 +61,7 @@ from securedrop_client.api_jobs.uploads import (
     SendReplyJobTimeoutError,
 )
 from securedrop_client.crypto import GpgHelper
+from securedrop_client.db import Reply
 from securedrop_client.queue import ApiJobQueue
 from securedrop_client.sync import ApiSync
 from securedrop_client.utils import check_dir_permissions
@@ -378,6 +379,14 @@ class Controller(QObject):
         self.session_maker = session_maker
         self.session = session_maker()
 
+        r1 = Reply(filename="1-foo")
+        r2 = Reply(filename="2-foo")
+        print(r1.machine, r1.state)
+        print(r2.machine, r2.state)
+        r1.send_pending()
+        print(r1.machine, r1.state)
+        print(r2.machine, r2.state)
+
         # Queue that handles running API job
         self.api_job_queue = ApiJobQueue(
             self.api, self.session_maker, self.main_queue_thread, self.file_download_queue_thread
diff --git a/securedrop_client/statemachines.py b/securedrop_client/statemachines.py
new file mode 100644
index 00000000..e9c03c74
--- /dev/null
+++ b/securedrop_client/statemachines.py
@@ -0,0 +1,46 @@
+# Copyright (c) 2021-present bigbag/sqlalchemy-state-machine authors and
+# contributors.
+# 
+# SPDX-License-Identifier: Apache-2.0
+
+import typing as t
+from dataclasses import dataclass
+
+from transitions import Machine
+
+
+@dataclass
+class StateConfig:
+    initial: t.Any
+    states: t.List[t.Any]
+    transitions: t.Optional[t.List[t.List[t.Any]]]
+    state_attribute: t.Optional[str] = "state"
+    status_attribute: t.Optional[str] = "status"
+    machine_name: t.Optional[str] = "machine"
+    after_state_change: t.Optional[t.Any] = None
+
+
+@dataclass
+class StateMixin:
+    state_config: StateConfig
+
+    @property
+    def state(self):
+        return getattr(self, self.state_config.status_attribute)
+
+    @state.setter
+    def state(self, value):
+        setattr(self, self.state_config.status_attribute, value)
+
+    @classmethod
+    def init_state_machine(cls, obj, *args, **kwargs):
+        machine = Machine(
+            model=obj,
+            states=cls.state_config.states,
+            transitions=cls.state_config.transitions,
+            initial=getattr(obj, obj.state_config.status_attribute) or cls.state_config.initial,
+            model_attribute=cls.state_config.state_attribute,
+            after_state_change=cls.state_config.after_state_change,
+        )
+
+        setattr(obj, cls.state_config.machine_name, machine)
\ No newline at end of file

transitions.patch

diff --git a/alembic/versions/f394059c0898_add_reply_state.py b/alembic/versions/f394059c0898_add_reply_state.py
new file mode 100644
index 00000000..41fb7472
--- /dev/null
+++ b/alembic/versions/f394059c0898_add_reply_state.py
@@ -0,0 +1,28 @@
+"""add Reply.state
+
+Revision ID: f394059c0898
+Revises: 414627c04463
+Create Date: 2023-03-07 17:22:39.406291
+
+"""
+import sqlalchemy as sa
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "f394059c0898"
+down_revision = "414627c04463"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column("replies", sa.Column("state", sa.String(length=100), nullable=False))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column("replies", "state")
+    # ### end Alembic commands ###
diff --git a/requirements/requirements.in b/requirements/requirements.in
index d843971a..125c2339 100644
--- a/requirements/requirements.in
+++ b/requirements/requirements.in
@@ -14,3 +14,4 @@ six==1.11.0
 sqlalchemy==1.3.3
 urllib3>=1.26.5
 jinja2==3.0.2  # per freedomofpress/securedrop#4829953
+transitions  # TODO: pin
diff --git a/securedrop_client/db.py b/securedrop_client/db.py
index 6e53de41..77dcd1ac 100644
--- a/securedrop_client/db.py
+++ b/securedrop_client/db.py
@@ -21,6 +21,9 @@ from sqlalchemy import (
 )
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import backref, relationship, scoped_session, sessionmaker
+from transitions import Machine
+
+from securedrop_client.statemachine import StateMachineMixin
 
 convention = {
     "ix": "ix_%(column_0_label)s",
@@ -424,13 +427,28 @@ class File(Base):
         return False
 
 
-class Reply(Base):
+PENDING = "Pending"
+SEND_PENDING = "SendPending"
+
+
+class Reply(Base, StateMachineMixin):
 
     __tablename__ = "replies"
     __table_args__ = (
         UniqueConstraint("source_id", "file_counter", name="uq_messages_source_id_file_counter"),
     )
 
+    machine = Machine(
+        model=None,
+        initial=None,
+        states=[PENDING, SEND_PENDING],
+        transitions=[
+            ["send_pending", PENDING, SEND_PENDING],
+        ],
+    )
+
+    state = Column(String(100), nullable=False)
+
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36), unique=True, nullable=False)
     source_id = Column(Integer, ForeignKey("sources.id"), nullable=False)
@@ -481,6 +499,7 @@ class Reply(Base):
             raise TypeError("Cannot manually set file_counter")
         filename = kwargs["filename"]
         kwargs["file_counter"] = int(filename.split("-")[0])
+        self.state = PENDING
         super().__init__(**kwargs)
 
     def __str__(self) -> str:
diff --git a/securedrop_client/logic.py b/securedrop_client/logic.py
index 5de96e3b..c8024786 100644
--- a/securedrop_client/logic.py
+++ b/securedrop_client/logic.py
@@ -61,6 +61,7 @@ from securedrop_client.api_jobs.uploads import (
     SendReplyJobTimeoutError,
 )
 from securedrop_client.crypto import GpgHelper
+from securedrop_client.db import Reply
 from securedrop_client.queue import ApiJobQueue
 from securedrop_client.sync import ApiSync
 from securedrop_client.utils import check_dir_permissions
@@ -378,6 +379,14 @@ class Controller(QObject):
         self.session_maker = session_maker
         self.session = session_maker()
 
+        r1 = Reply(filename="1-foo")
+        r2 = Reply(filename="2-foo")
+        print(r1.machine, r1.state)
+        print(r2.machine, r2.state)
+        r1.send_pending()
+        print(r1.machine, r1.state)
+        print(r2.machine, r2.state)
+
         # Queue that handles running API job
         self.api_job_queue = ApiJobQueue(
             self.api, self.session_maker, self.main_queue_thread, self.file_download_queue_thread
diff --git a/securedrop_client/statemachine.py b/securedrop_client/statemachine.py
new file mode 100644
index 00000000..4f5ba023
--- /dev/null
+++ b/securedrop_client/statemachine.py
@@ -0,0 +1,10 @@
+from functools import partial
+
+class StateMachineMixin:
+    def __getattribute__(self, item):
+        try:
+            return super(StateMachineMixin, self).__getattribute__(item)
+        except AttributeError:
+            if item in self.machine.events:
+                return partial(self.machine.events[item].trigger, self)
+            raise
\ No newline at end of file