From 0aa3d941004acaade4d1d54d47c7c218272628e3 Mon Sep 17 00:00:00 2001
From: Liz <liz@adafruit.com>
Date: Tue, 13 May 2025 13:56:40 -0400
Subject: [PATCH] update parser api

Update parser API so that a MIDI file is passed to parse() rather than during the init. This way you can dynamically pass a midi file to the parser in user code
---
 README.rst                             |  5 +++--
 adafruit_midi_parser.py                | 22 +++++++++++++++++++---
 examples/midi_parser_player_example.py |  4 ++--
 examples/midi_parser_simpletest.py     |  4 ++--
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/README.rst b/README.rst
index 26b3f04..36da81b 100644
--- a/README.rst
+++ b/README.rst
@@ -94,6 +94,8 @@ Usage Example
 
     import adafruit_midi_parser
 
+    parser = adafruit_midi_parser.MIDIParser()
+
     midi_file = "/song.mid"
 
     print("MIDI File Analyzer")
@@ -102,9 +104,8 @@ Usage Example
     file_list = os.listdir("/")
     if midi_file[1:] in file_list:
         print(f"\nFound MIDI file {midi_file}")
-        parser = adafruit_midi_parser.MIDIParser(midi_file)
         print("\nParsing MIDI file...")
-        parser.parse()
+        parser.parse(midi_file)
         print("\nMIDI File Information:")
         print("=====================")
         print(f"Format Type: {parser.format_type}")
diff --git a/adafruit_midi_parser.py b/adafruit_midi_parser.py
index fc0eea6..4e7e1bd 100644
--- a/adafruit_midi_parser.py
+++ b/adafruit_midi_parser.py
@@ -46,13 +46,13 @@ class MIDIParser:
     :param str filename: Path to the MIDI file
     """
 
-    def __init__(self, filename: str) -> None:
+    def __init__(self) -> None:
         """
         Initialize the MIDI parser.
 
         :param str filename: Path to the MIDI file
         """
-        self._filename: str = filename
+        self._filename: Optional[str] = None
         self._events: List[Dict[str, Any]] = []
         self._tempo: int = 500000  # Default tempo (microseconds per quarter note)
         self._ticks_per_beat: int = 480  # Default time division
@@ -188,7 +188,21 @@ def _read_variable_length(data: bytes, offset: int) -> Tuple[int, int]:
                 break
         return value, offset
 
-    def parse(self, debug: bool = False) -> bool:  # noqa: PLR0912 PLR0915 PLR0914
+    def clear(self) -> None:
+        """
+        Clear all parsed data and reset the parser state.
+        """
+        self._filename = None
+        self._events = []
+        self._tempo = 500000  # Default tempo
+        self._ticks_per_beat = 480  # Default division
+        self._current_event_index = 0
+        self._format_type = 0
+        self._num_tracks = 0
+        self._parsed = False
+        self._last_absolute_time = 0
+
+    def parse(self, filename: str, debug: bool = False) -> bool:  # noqa: PLR0912 PLR0915 PLR0914
         """
         Parse the MIDI file and extract events.
 
@@ -197,6 +211,8 @@ def parse(self, debug: bool = False) -> bool:  # noqa: PLR0912 PLR0915 PLR0914
         :rtype: bool
         :raises MIDIParseError: If the file doesn't exist or is not a valid MIDI file
         """
+        self.clear()
+        self._filename = filename
         try:  # noqa: PLR1702
             with open(self._filename, "rb") as file:
                 data = file.read()
diff --git a/examples/midi_parser_player_example.py b/examples/midi_parser_player_example.py
index 14a7290..e6a91f5 100644
--- a/examples/midi_parser_player_example.py
+++ b/examples/midi_parser_player_example.py
@@ -54,10 +54,10 @@ def on_playback_complete(self):  # noqa: PLR6301
     print(f"Found MIDI file {midi_file}")
 
     # Create a MIDIParser instance
-    parser = adafruit_midi_parser.MIDIParser(midi_file)
+    parser = adafruit_midi_parser.MIDIParser()
 
     # Parse the file
-    parser.parse()
+    parser.parse(midi_file)
     print(f"Successfully parsed! Found {len(parser.events)} events.")
     print(f"BPM: {parser.bpm:.1f}")
     print(f"Note Count: {parser.note_count}")
diff --git a/examples/midi_parser_simpletest.py b/examples/midi_parser_simpletest.py
index 919c6b7..64736b0 100644
--- a/examples/midi_parser_simpletest.py
+++ b/examples/midi_parser_simpletest.py
@@ -21,9 +21,9 @@
 # Check if the file exists
 if midi_file[1:] in file_list:
     print(f"\nFound MIDI file {midi_file}")
-    parser = adafruit_midi_parser.MIDIParser(midi_file)
+    parser = adafruit_midi_parser.MIDIParser()
     print("\nParsing MIDI file...")
-    parser.parse()
+    parser.parse(midi_file)
     print("\nMIDI File Information:")
     print("=====================")
     print(f"Format Type: {parser.format_type}")