Add post --reply-last option

fixes #464

tests/integration/test_post.py

@@ -7,6 +7,7 @@
 
 from tests.integration.conftest import ASSETS_DIR, Run, assert_ok, posted_status_id
 from toot import CLIENT_NAME, CLIENT_WEBSITE, api, cli
+from toot.cache import clear_last_post_id, get_last_post_id
 from toot.utils import get_text
 from unittest import mock
 
@@ -340,7 +341,7 @@ def test_media_attachment_without_text(mock_read, mock_ml, app, user, run):
         assert attachment["meta"]["original"]["size"] == "50x50"
 
 
-def test_reply_thread(app, user, friend, run):
+def test_reply_to(app, user, friend, run):
     status = api.post_status(app, friend, "This is the status").json()
 
     result = run(cli.post.post, "--reply-to", status["id"], "This is the reply")
@@ -362,3 +363,38 @@ def test_reply_thread(app, user, friend, run):
     assert user.username in s2
     assert status["id"] in s1
     assert reply["id"] in s2
+
+
+def test_reply_last(app, user, run):
+    result_1 = run(cli.post.post, "one")
+    status_id_1 = posted_status_id(result_1.stdout)
+    assert get_last_post_id(app, user) == status_id_1
+
+    result_2 = run(cli.post.post, "two", "--reply-last")
+    status_id_2 = posted_status_id(result_2.stdout)
+    assert get_last_post_id(app, user) == status_id_2
+
+    result_3 = run(cli.post.post, "two", "--reply-last")
+    status_id_3 = posted_status_id(result_3.stdout)
+    assert get_last_post_id(app, user) == status_id_3
+
+    status_1 = api.fetch_status(app, user, status_id_1).json()
+    status_2 = api.fetch_status(app, user, status_id_2).json()
+    status_3 = api.fetch_status(app, user, status_id_3).json()
+
+    assert status_1["in_reply_to_id"] is None
+    assert status_2["in_reply_to_id"] == status_id_1
+    assert status_3["in_reply_to_id"] == status_id_2
+
+
+def test_reply_last_fails_if_no_last_id(app, user, run: Run):
+    clear_last_post_id(app, user)
+    result = run(cli.post.post, "one", "--reply-last")
+    assert result.exit_code == 1
+    assert result.stderr.strip() == f"Error: Cannot reply-last, no previous post ID found for {user.username}@{app.instance}"
+
+
+def test_reply_last_and_reply_to_are_exclusive(app, user, run: Run):
+    result = run(cli.post.post, "one", "--reply-last", "--reply-to", "123")
+    assert result.exit_code == 1
+    assert result.stderr.strip() == f"Error: --reply-last and --reply-to are mutually exclusive"

toot/cache.py

@@ -0,0 +1,61 @@
+import os
+import sys
+
+from pathlib import Path
+from typing import Optional
+
+from toot import App, User
+
+CACHE_SUBFOLDER = "toot"
+
+
+def save_last_post_id(app: App, user: User, id: str) -> None:
+    """Save ID of the last post posted to this instance"""
+    path = _last_post_id_path(app, user)
+    with open(path, "w") as f:
+        f.write(id)
+
+
+def get_last_post_id(app: App, user: User) -> Optional[str]:
+    """Retrieve ID of the last post posted to this instance"""
+    path = _last_post_id_path(app, user)
+    if path.exists():
+        with open(path, "r") as f:
+            return f.read()
+
+
+def clear_last_post_id(app: App, user: User) -> None:
+    """Delete the cached last post ID for this instance"""
+    path = _last_post_id_path(app, user)
+    path.unlink(missing_ok=True)
+
+
+def _last_post_id_path(app: App, user: User):
+    return get_cache_dir("last_post_ids") / f"{user.username}_{app.instance}"
+
+
+def get_cache_dir(subdir: Optional[str] = None) -> Path:
+    path = _cache_dir_path()
+    if subdir:
+        path = path / subdir
+    path.mkdir(parents=True, exist_ok=True)
+    return path
+
+
+def _cache_dir_path() -> Path:
+    """Returns the path to the cache directory"""
+
+    # Windows
+    if sys.platform == "win32" and "LOCALAPPDATA" in os.environ:
+        return Path(os.environ["LOCALAPPDATA"], CACHE_SUBFOLDER)
+
+    # Mac OS
+    if sys.platform == "darwin":
+        return Path.home() / "Library" / "Caches" / CACHE_SUBFOLDER
+
+    # Respect XDG_CONFIG_HOME env variable if set
+    # https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
+    if "XDG_CACHE_HOME" in os.environ:
+        return Path(os.environ["XDG_CACHE_HOME"], CACHE_SUBFOLDER)
+
+    return Path.home() / ".cache" / CACHE_SUBFOLDER

toot/cli/post.py

@@ -7,6 +7,7 @@
 from typing import BinaryIO, Optional, Tuple
 
 from toot import api, config
+from toot.cache import get_last_post_id, save_last_post_id
 from toot.cli import AccountParamType, cli, json_option, pass_context, Context
 from toot.cli import DURATION_EXAMPLES, VISIBILITY_CHOICES
 from toot.tui.constants import VISIBILITY_OPTIONS  # move to top-level ?
@@ -60,6 +61,12 @@
     "--reply-to", "-r",
     help="ID of the status being replied to, if status is a reply.",
 )
+@click.option(
+    "--reply-last", "-R",
+    help="Reply to the last posted status to continue the thread.",
+    is_flag=True,
+    default=False,
+)
 @click.option(
     "--language", "-l",
     help="ISO 639-1 language code of the toot, to skip automatic detection.",
@@ -137,7 +144,8 @@ def post(
     poll_multiple: bool,
     poll_hide_totals: bool,
     json: bool,
-    using: str
+    using: str,
+    reply_last: bool,
 ):
     """Post a new status"""
     if len(media) > 4:
@@ -153,6 +161,7 @@ def post(
     media_ids = _upload_media(app, user, media, descriptions, thumbnails)
     status_text = _get_status_text(text, editor, media)
     scheduled_at = _get_scheduled_at(scheduled_at, scheduled_in)
+    reply_to = _get_reply_to(app, user, reply_to, reply_last)
 
     if not status_text and not media_ids:
         raise click.ClickException("You must specify either text or media to post.")
@@ -186,6 +195,8 @@ def post(
         else:
             click.echo(f"Toot posted: {status['url']}")
 
+        save_last_post_id(app, user, status["id"])
+
     delete_tmp_status_file()
 
 
@@ -245,6 +256,20 @@ def _get_scheduled_at(scheduled_at, scheduled_in):
     return None
 
 
+def _get_reply_to(app, user, reply_to, reply_last):
+    if reply_last and reply_to:
+        raise click.ClickException("--reply-last and --reply-to are mutually exclusive")
+
+    if reply_last:
+        last_id = get_last_post_id(app, user)
+        if last_id:
+            return last_id
+        else:
+            raise click.ClickException(f"Cannot reply-last, no previous post ID found for {user.username}@{app.instance}")
+
+    return reply_to
+
+
 def _upload_media(app, user, media, descriptions, thumbnails):
     # Match media to corresponding descriptions and thumbnail
     media = media or []