[cli] Centralize preconditions in CliContext

scenedetect/_cli/__init__.py

@@ -20,6 +20,8 @@
 
 import inspect
 import logging
+import os
+import os.path
 import typing as ty
 
 import click
@@ -32,10 +34,9 @@
     CONFIG_MAP,
     DEFAULT_JPG_QUALITY,
     DEFAULT_WEBP_QUALITY,
-    USER_CONFIG,
     TimecodeFormat,
 )
-from scenedetect._cli.context import CliContext, check_split_video_requirements
+from scenedetect._cli.context import USER_CONFIG, CliContext, check_split_video_requirements
 from scenedetect.backends import AVAILABLE_BACKENDS
 from scenedetect.detectors import (
     AdaptiveDetector,
@@ -315,8 +316,10 @@ def scenedetect(
 
     Global options (e.g. -i/--input, -c/--config) must be specified before any commands and their options. The order of commands is not strict, but each command must only be specified once.
     """
-    assert isinstance(ctx.obj, CliContext)
-    ctx.obj.handle_options(
+    ctx = ctx.obj
+    assert isinstance(ctx, CliContext)
+
+    ctx.handle_options(
         input_path=input,
         output=output,
         framerate=framerate,
@@ -344,7 +347,6 @@ def scenedetect(
 @click.pass_context
 def help_command(ctx: click.Context, command_name: str):
     """Print help for command (`help [command]`)."""
-    assert isinstance(ctx.obj, CliContext)
     assert isinstance(ctx.parent.command, click.MultiCommand)
     parent_command = ctx.parent.command
     all_commands = set(parent_command.list_commands(ctx))
@@ -368,7 +370,6 @@ def help_command(ctx: click.Context, command_name: str):
 @click.pass_context
 def about_command(ctx: click.Context):
     """Print license/copyright info."""
-    assert isinstance(ctx.obj, CliContext)
     click.echo("")
     click.echo(click.style(_LINE_SEPARATOR, fg="cyan"))
     click.echo(click.style(" About PySceneDetect %s" % _PROGRAM_VERSION, fg="yellow"))
@@ -381,7 +382,6 @@ def about_command(ctx: click.Context):
 @click.pass_context
 def version_command(ctx: click.Context):
     """Print PySceneDetect version."""
-    assert isinstance(ctx.obj, CliContext)
     click.echo("")
     click.echo(get_system_version_info())
     ctx.exit()
@@ -431,12 +431,23 @@ def time_command(
 
         {scenedetect_with_video} time --start 0 --end 1000
     """
-    assert isinstance(ctx.obj, CliContext)
-    ctx.obj.handle_time(
-        start=start,
-        duration=duration,
-        end=end,
-    )
+    ctx = ctx.obj
+    assert isinstance(ctx, CliContext)
+
+    if duration is not None and end is not None:
+        raise click.BadParameter(
+            "Only one of --duration/-d or --end/-e can be specified, not both.",
+            param_hint="time",
+        )
+    logger.debug("Setting video time:\n    start: %s, duration: %s, end: %s", start, duration, end)
+    # *NOTE*: The Python API uses 0-based frame indices, but the CLI uses 1-based indices to
+    # match the default start number used by `ffmpeg` when saving frames as images. As such,
+    # we must correct start time if set as frames. See the test_cli_time* tests for for details.
+    ctx.start_time = ctx.parse_timecode(start, correct_pts=True)
+    ctx.end_time = ctx.parse_timecode(end)
+    ctx.duration = ctx.parse_timecode(duration)
+    if ctx.start_time and ctx.end_time and (ctx.start_time + 1) > ctx.end_time:
+        raise click.BadParameter("-e/--end time must be greater than -s/--start")
 
 
 @click.command("detect-content", cls=_Command)
@@ -535,17 +546,17 @@ def detect_content_command(
 
         {scenedetect_with_video} detect-content --threshold 27.5
     """
-    assert isinstance(ctx.obj, CliContext)
-    detector_args = ctx.obj.get_detect_content_params(
+    ctx = ctx.obj
+    assert isinstance(ctx, CliContext)
+    detector_args = ctx.get_detect_content_params(
         threshold=threshold,
         luma_only=luma_only,
         min_scene_len=min_scene_len,
         weights=weights,
         kernel_size=kernel_size,
         filter_mode=filter_mode,
     )
-    logger.debug("Adding detector: ContentDetector(%s)", detector_args)
-    ctx.obj.add_detector(ContentDetector(**detector_args))
+    ctx.add_detector(ContentDetector, detector_args)
 
 
 @click.command("detect-adaptive", cls=_Command)
@@ -646,8 +657,9 @@ def detect_adaptive_command(
 
         {scenedetect_with_video} detect-adaptive --threshold 3.2
     """
-    assert isinstance(ctx.obj, CliContext)
-    detector_args = ctx.obj.get_detect_adaptive_params(
+    ctx = ctx.obj
+    assert isinstance(ctx, CliContext)
+    detector_args = ctx.get_detect_adaptive_params(
         threshold=threshold,
         min_content_val=min_content_val,
         min_delta_hsv=min_delta_hsv,
@@ -657,8 +669,7 @@ def detect_adaptive_command(
         weights=weights,
         kernel_size=kernel_size,
     )
-    logger.debug("Adding detector: AdaptiveDetector(%s)", detector_args)
-    ctx.obj.add_detector(AdaptiveDetector(**detector_args))
+    ctx.add_detector(AdaptiveDetector, detector_args)
 
 
 @click.command("detect-threshold", cls=_Command)
@@ -725,15 +736,15 @@ def detect_threshold_command(
 
         {scenedetect_with_video} detect-threshold --threshold 15
     """
-    assert isinstance(ctx.obj, CliContext)
-    detector_args = ctx.obj.get_detect_threshold_params(
+    ctx = ctx.obj
+    assert isinstance(ctx, CliContext)
+    detector_args = ctx.get_detect_threshold_params(
         threshold=threshold,
         fade_bias=fade_bias,
         add_last_scene=add_last_scene,
         min_scene_len=min_scene_len,
     )
-    logger.debug("Adding detector: ThresholdDetector(%s)", detector_args)
-    ctx.obj.add_detector(ThresholdDetector(**detector_args))
+    ctx.add_detector(ThresholdDetector, detector_args)
 
 
 @click.command("detect-hist", cls=_Command)
@@ -795,14 +806,12 @@ def detect_hist_command(
 
         {scenedetect_with_video} detect-hist --threshold 0.1 --bins 240
     """
-    assert isinstance(ctx.obj, CliContext)
-
-    assert isinstance(ctx.obj, CliContext)
-    detector_args = ctx.obj.get_detect_hist_params(
+    ctx = ctx.obj
+    assert isinstance(ctx, CliContext)
+    detector_args = ctx.get_detect_hist_params(
         threshold=threshold, bins=bins, min_scene_len=min_scene_len
     )
-    logger.debug("Adding detector: HistogramDetector(%s)", detector_args)
-    ctx.obj.add_detector(HistogramDetector(**detector_args))
+    ctx.add_detector(HistogramDetector, detector_args)
 
 
 @click.command("detect-hash", cls=_Command)
@@ -880,14 +889,12 @@ def detect_hash_command(
 
         {scenedetect_with_video} detect-hash --size 32 --lowpass 3
     """
-    assert isinstance(ctx.obj, CliContext)
-
-    assert isinstance(ctx.obj, CliContext)
-    detector_args = ctx.obj.get_detect_hash_params(
+    ctx = ctx.obj
+    assert isinstance(ctx, CliContext)
+    detector_args = ctx.get_detect_hash_params(
         threshold=threshold, size=size, lowpass=lowpass, min_scene_len=min_scene_len
     )
-    logger.debug("Adding detector: HashDetector(%s)", detector_args)
-    ctx.obj.add_detector(HashDetector(**detector_args))
+    ctx.add_detector(HashDetector, detector_args)
 
 
 @click.command("load-scenes", cls=_Command)
@@ -921,9 +928,23 @@ def load_scenes_command(
 
         {scenedetect_with_video} load-scenes -i scenes.csv --start-col-name "Start Timecode"
     """
-    assert isinstance(ctx.obj, CliContext)
-    logger.debug("Loading scenes from %s (start_col_name = %s)", input, start_col_name)
-    ctx.obj.handle_load_scenes(input=input, start_col_name=start_col_name)
+    ctx = ctx.obj
+    assert isinstance(ctx, CliContext)
+
+    logger.debug("Will load scenes from %s (start_col_name = %s)", input, start_col_name)
+    if ctx.scene_manager.get_num_detectors() > 0:
+        raise click.ClickException("The load-scenes command cannot be used with detectors.")
+    if ctx.load_scenes_input:
+        raise click.ClickException("The load-scenes command must only be specified once.")
+    input = os.path.abspath(input)
+    if not os.path.exists(input):
+        raise click.BadParameter(
+            f"Could not load scenes, file does not exist: {input}", param_hint="-i/--input"
+        )
+    ctx.load_scenes_input = input
+    ctx.load_scenes_column_name = ctx.config.get_value(
+        "load-scenes", "start-col-name", start_col_name
+    )
 
 
 @click.command("export-html", cls=_Command)
@@ -970,7 +991,7 @@ def export_html_command(
     """Export scene list to HTML file. Requires save-images unless --no-images is specified."""
     ctx = ctx.obj
     assert isinstance(ctx, CliContext)
-    ctx.ensure_input_open()
+
     no_images = no_images or ctx.config.get_value("export-html", "no-images")
     if not ctx.save_images and not no_images:
         raise click.BadArgumentUsage(
@@ -1037,7 +1058,7 @@ def list_scenes_command(
     """Create scene list CSV file (will be named $VIDEO_NAME-Scenes.csv by default)."""
     ctx = ctx.obj
     assert isinstance(ctx, CliContext)
-    ctx.ensure_input_open()
+
     no_output_file = no_output_file or ctx.config.get_value("list-scenes", "no-output-file")
     scene_list_dir = ctx.config.get_value("list-scenes", "output", output, ignore_default=True)
     scene_list_name_format = ctx.config.get_value("list-scenes", "filename", filename)
@@ -1162,7 +1183,7 @@ def split_video_command(
     """
     ctx = ctx.obj
     assert isinstance(ctx, CliContext)
-    ctx.ensure_input_open()
+
     check_split_video_requirements(use_mkvmerge=mkvmerge)
     if "%" in ctx.video_stream.path or "://" in ctx.video_stream.path:
         error = "The split-video command is incompatible with image sequences/URLs."
@@ -1362,7 +1383,7 @@ def save_images_command(
     """
     ctx = ctx.obj
     assert isinstance(ctx, CliContext)
-    ctx.ensure_input_open()
+
     if "://" in ctx.video_stream.path:
         error_str = "\nThe save-images command is incompatible with URLs."
         logger.error(error_str)