refactor(Track): Move from OnXyz callables to Event observer

Fixes #85

devine/commands/dl.py

@@ -43,6 +43,7 @@ from devine.core.console import console
 from devine.core.constants import DOWNLOAD_LICENCE_ONLY, AnyTrack, context_settings
 from devine.core.credential import Credential
 from devine.core.drm import DRM_T, Widevine
+from devine.core.events import events
 from devine.core.proxies import Basic, Hola, NordVPN
 from devine.core.service import Service
 from devine.core.services import Services
@@ -324,6 +325,14 @@ class dl:
                 with console.status(f"Delaying by {delay} seconds..."):
                     time.sleep(delay)
 
+            with console.status("Subscribing to events...", spinner="dots"):
+                events.reset()
+                events.subscribe(events.Types.SEGMENT_DOWNLOADED, service.on_segment_downloaded)
+                events.subscribe(events.Types.TRACK_DOWNLOADED, service.on_track_downloaded)
+                events.subscribe(events.Types.TRACK_DECRYPTED, service.on_track_decrypted)
+                events.subscribe(events.Types.TRACK_REPACKED, service.on_track_repacked)
+                events.subscribe(events.Types.TRACK_MULTIPLEX, service.on_track_multiplex)
+
             with console.status("Getting tracks...", spinner="dots"):
                 title.tracks.add(service.get_tracks(title), warn_only=True)
                 title.tracks.chapters = service.get_chapters(title)
@@ -339,8 +348,13 @@ class dl:
                     non_sdh_sub = deepcopy(subtitle)
                     non_sdh_sub.id += "_stripped"
                     non_sdh_sub.sdh = False
-                    non_sdh_sub.OnMultiplex = lambda: non_sdh_sub.strip_hearing_impaired()
                     title.tracks.add(non_sdh_sub)
+                    events.subscribe(
+                        events.Types.TRACK_MULTIPLEX,
+                        lambda track: (
+                            track.strip_hearing_impaired()
+                        ) if track.id == non_sdh_sub.id else None
+                    )
 
             with console.status("Sorting tracks by language and bitrate...", spinner="dots"):
                 title.tracks.sort_videos(by_language=v_lang or lang)
@@ -636,8 +650,7 @@ class dl:
                         if track.needs_repack:
                             track.repackage()
                             has_repacked = True
-                            if callable(track.OnRepacked):
+                            events.emit(events.Types.TRACK_REPACKED, track=track)
-                                track.OnRepacked()
                     if has_repacked:
                         # we don't want to fill up the log with "Repacked x track"
                         self.log.info("Repacked one or more tracks with FFMPEG")

devine/core/manifests/dash.py

@@ -24,6 +24,7 @@ from requests import Session
 from devine.core.constants import DOWNLOAD_CANCELLED, DOWNLOAD_LICENCE_ONLY, AnyTrack
 from devine.core.downloaders import requests as requests_downloader
 from devine.core.drm import Widevine
+from devine.core.events import events
 from devine.core.tracks import Audio, Subtitle, Tracks, Video
 from devine.core.utilities import is_close_match, try_ensure_utf8
 from devine.core.utils.xml import load_xml
@@ -474,8 +475,8 @@ class DASH:
             max_workers=16
         ):
             file_downloaded = status_update.get("file_downloaded")
-            if file_downloaded and callable(track.OnSegmentDownloaded):
+            if file_downloaded:
-                track.OnSegmentDownloaded(file_downloaded)
+                events.emit(events.Types.SEGMENT_DOWNLOADED, track=track, segment=file_downloaded)
             else:
                 downloaded = status_update.get("downloaded")
                 if downloaded and downloaded.endswith("/s"):
@@ -514,15 +515,18 @@ class DASH:
                 progress(advance=1)
 
         track.path = save_path
-        if callable(track.OnDownloaded):
+        events.emit(events.Types.TRACK_DOWNLOADED, track=track)
-            track.OnDownloaded()
 
         if drm:
             progress(downloaded="Decrypting", completed=0, total=100)
             drm.decrypt(save_path)
             track.drm = None
-            if callable(track.OnDecrypted):
+            events.emit(
-                track.OnDecrypted(drm)
+                events.Types.TRACK_DECRYPTED,
+                track=track,
+                drm=drm,
+                segment=None
+            )
             progress(downloaded="Decrypting", advance=100)
 
         save_dir.rmdir()

devine/core/manifests/hls.py

@@ -22,6 +22,7 @@ from requests import Session
 from devine.core.constants import DOWNLOAD_CANCELLED, DOWNLOAD_LICENCE_ONLY, AnyTrack
 from devine.core.downloaders import requests as requests_downloader
 from devine.core.drm import DRM_T, ClearKey, Widevine
+from devine.core.events import events
 from devine.core.tracks import Audio, Subtitle, Tracks, Video
 from devine.core.utilities import get_binary_path, get_extension, is_close_match, try_ensure_utf8
 
@@ -282,8 +283,8 @@ class HLS:
             max_workers=16
         ):
             file_downloaded = status_update.get("file_downloaded")
-            if file_downloaded and callable(track.OnSegmentDownloaded):
+            if file_downloaded:
-                track.OnSegmentDownloaded(file_downloaded)
+                events.emit(events.Types.SEGMENT_DOWNLOADED, track=track, segment=file_downloaded)
             else:
                 downloaded = status_update.get("downloaded")
                 if downloaded and downloaded.endswith("/s"):
@@ -381,8 +382,12 @@ class HLS:
                 drm.decrypt(merged_path)
                 merged_path.rename(decrypted_path)
 
-                if callable(track.OnDecrypted):
+                events.emit(
-                    track.OnDecrypted(drm, decrypted_path)
+                    events.Types.TRACK_DECRYPTED,
+                    track=track,
+                    drm=drm,
+                    segment=decrypted_path
+                )
 
                 return decrypted_path
 
@@ -537,8 +542,7 @@ class HLS:
         progress(downloaded="Downloaded")
 
         track.path = save_path
-        if callable(track.OnDownloaded):
+        events.emit(events.Types.TRACK_DOWNLOADED, track=track)
-            track.OnDownloaded()
 
     @staticmethod
     def merge_segments(segments: list[Path], save_path: Path) -> int:

devine/core/service.py

@@ -3,10 +3,12 @@ import logging
 from abc import ABCMeta, abstractmethod
 from collections.abc import Generator
 from http.cookiejar import CookieJar
+from pathlib import Path
 from typing import Optional, Union
 from urllib.parse import urlparse
 
 import click
+import m3u8
 import requests
 from requests.adapters import HTTPAdapter, Retry
 from rich.padding import Padding
@@ -17,6 +19,7 @@ from devine.core.config import config
 from devine.core.console import console
 from devine.core.constants import AnyTrack
 from devine.core.credential import Credential
+from devine.core.drm import DRM_T
 from devine.core.search_result import SearchResult
 from devine.core.titles import Title_T, Titles_T
 from devine.core.tracks import Chapters, Tracks
@@ -235,5 +238,53 @@ class Service(metaclass=ABCMeta):
         option `chapter_fallback_name`. For example, `"Chapter {i:02}"` for "Chapter 01".
         """
 
+    # Optional Event methods
+
+    def on_segment_downloaded(self, track: AnyTrack, segment: Path) -> None:
+        """
+        Called when one of a Track's Segments has finished downloading.
+
+        Parameters:
+            track: The Track object that had a Segment downloaded.
+            segment: The Path to the Segment that was downloaded.
+        """
+
+    def on_track_downloaded(self, track: AnyTrack) -> None:
+        """
+        Called when a Track has finished downloading.
+
+        Parameters:
+            track: The Track object that was downloaded.
+        """
+
+    def on_track_decrypted(self, track: AnyTrack, drm: DRM_T, segment: Optional[m3u8.Segment] = None) -> None:
+        """
+        Called when a Track has finished decrypting.
+
+        Parameters:
+            track: The Track object that was decrypted.
+            drm: The DRM object it decrypted with.
+            segment: The HLS segment information that was decrypted.
+        """
+
+    def on_track_repacked(self, track: AnyTrack) -> None:
+        """
+        Called when a Track has finished repacking.
+
+        Parameters:
+            track: The Track object that was repacked.
+        """
+
+    def on_track_multiplex(self, track: AnyTrack) -> None:
+        """
+        Called when a Track is about to be Multiplexed into a Container.
+
+        Note: Right now only MKV containers are multiplexed but in the future
+        this may also be called when multiplexing to other containers like
+        MP4 via ffmpeg/mp4box.
+
+        Parameters:
+            track: The Track object that was repacked.
+        """
 
 __all__ = ("Service",)

devine/core/tracks/track.py

@@ -12,7 +12,6 @@ from typing import Any, Callable, Iterable, Optional, Union
 from uuid import UUID
 from zlib import crc32
 
-import m3u8
 from langcodes import Language
 from requests import Session
 
@@ -20,6 +19,7 @@ from devine.core.config import config
 from devine.core.constants import DOWNLOAD_CANCELLED, DOWNLOAD_LICENCE_ONLY
 from devine.core.downloaders import aria2c, curl_impersonate, requests
 from devine.core.drm import DRM_T, Widevine
+from devine.core.events import events
 from devine.core.utilities import get_binary_path, get_boxes, try_ensure_utf8
 from devine.core.utils.subprocess import ffprobe
 
@@ -122,17 +122,6 @@ class Track:
         # TODO: Currently using OnFoo event naming, change to just segment_filter
         self.OnSegmentFilter: Optional[Callable] = None
 
-        # Called after one of the Track's segments have downloaded
-        self.OnSegmentDownloaded: Optional[Callable[[Path], None]] = None
-        # Called after the Track has downloaded
-        self.OnDownloaded: Optional[Callable] = None
-        # Called after the Track or one of its segments have been decrypted
-        self.OnDecrypted: Optional[Callable[[DRM_T, Optional[m3u8.Segment]], None]] = None
-        # Called after the Track has been repackaged
-        self.OnRepacked: Optional[Callable] = None
-        # Called before the Track is multiplexed
-        self.OnMultiplex: Optional[Callable] = None
-
     def __repr__(self) -> str:
         return "{name}({items})".format(
             name=self.__class__.__name__,
@@ -257,15 +246,18 @@ class Track:
                         save_path.with_suffix(f"{save_path.suffix}.aria2__temp").unlink(missing_ok=True)
 
                         self.path = save_path
-                        if callable(self.OnDownloaded):
+                        events.emit(events.Types.TRACK_DOWNLOADED, track=self)
-                            self.OnDownloaded()
 
                         if drm:
                             progress(downloaded="Decrypting", completed=0, total=100)
                             drm.decrypt(save_path)
                             self.drm = None
-                            if callable(self.OnDecrypted):
+                            events.emit(
-                                self.OnDecrypted(drm)
+                                events.Types.TRACK_DECRYPTED,
+                                track=self,
+                                drm=drm,
+                                segment=None
+                            )
                             progress(downloaded="Decrypted", completed=100)
 
                         if track_type == "Subtitle" and self.codec.name not in ("fVTT", "fTTML"):
@@ -299,8 +291,7 @@ class Track:
             if self.path.stat().st_size <= 3:  # Empty UTF-8 BOM == 3 bytes
                 raise IOError("Download failed, the downloaded file is empty.")
 
-        if callable(self.OnDownloaded):
+        events.emit(events.Types.TRACK_DOWNLOADED, track=self)
-            self.OnDownloaded(self)
 
     def delete(self) -> None:
         if self.path:

devine/core/tracks/tracks.py

@@ -14,6 +14,7 @@ from rich.tree import Tree
 from devine.core.config import config
 from devine.core.console import console
 from devine.core.constants import LANGUAGE_MAX_DISTANCE, AnyTrack, TrackT
+from devine.core.events import events
 from devine.core.tracks.attachment import Attachment
 from devine.core.tracks.audio import Audio
 from devine.core.tracks.chapters import Chapter, Chapters
@@ -337,8 +338,7 @@ class Tracks:
         for i, vt in enumerate(self.videos):
             if not vt.path or not vt.path.exists():
                 raise ValueError("Video Track must be downloaded before muxing...")
-            if callable(vt.OnMultiplex):
+            events.emit(events.Types.TRACK_MULTIPLEX, track=vt)
-                vt.OnMultiplex()
             cl.extend([
                 "--language", f"0:{vt.language}",
                 "--default-track", f"0:{i == 0}",
@@ -350,8 +350,7 @@ class Tracks:
         for i, at in enumerate(self.audio):
             if not at.path or not at.path.exists():
                 raise ValueError("Audio Track must be downloaded before muxing...")
-            if callable(at.OnMultiplex):
+            events.emit(events.Types.TRACK_MULTIPLEX, track=at)
-                at.OnMultiplex()
             cl.extend([
                 "--track-name", f"0:{at.get_track_name() or ''}",
                 "--language", f"0:{at.language}",
@@ -365,8 +364,7 @@ class Tracks:
         for st in self.subtitles:
             if not st.path or not st.path.exists():
                 raise ValueError("Text Track must be downloaded before muxing...")
-            if callable(st.OnMultiplex):
+            events.emit(events.Types.TRACK_MULTIPLEX, track=st)
-                st.OnMultiplex()
             default = bool(self.audio and is_close_match(st.language, [self.audio[0].language]) and st.forced)
             cl.extend([
                 "--track-name", f"0:{st.get_track_name() or ''}",