generate.py

from generation_utils import *
import random


class GenerateMidiText:
    """Generating music with Class

    LOGIC:

    FOR GENERATING FROM SCRATCH:
    - self.generate_one_new_track()
    it calls
        - self.generate_until_track_end()

    FOR GENERATING NEW BARS:
    - self.generate_one_more_bar()
    it calls
        - self.process_prompt_for_next_bar()
        - self.generate_until_track_end()"""

    def __init__(self, model, tokenizer, piece_by_track=[]):
        self.model = model
        self.tokenizer = tokenizer
        # default initialization
        self.initialize_default_parameters()
        self.initialize_dictionaries(piece_by_track)

    """Setters"""

    def initialize_default_parameters(self):
        self.set_device()
        self.set_attention_length()
        self.generate_until = "TRACK_END"
        self.set_force_sequence_lenth()
        self.set_nb_bars_generated()
        self.set_improvisation_level(0)

    def initialize_dictionaries(self, piece_by_track):
        self.piece_by_track = piece_by_track

    def set_device(self, device="cpu"):
        self.device = ("cpu",)

    def set_attention_length(self):
        self.max_length = self.model.config.n_positions
        print(
            f"Attention length set to {self.max_length} -> 'model.config.n_positions'"
        )

    def set_force_sequence_lenth(self, force_sequence_length=True):
        self.force_sequence_length = force_sequence_length

    def set_improvisation_level(self, improvisation_value):
        self.no_repeat_ngram_size = improvisation_value
        print("--------------------")
        print(f"no_repeat_ngram_size set to {improvisation_value}")
        print("--------------------")

    def reset_temperatures(self, track_id, temperature):
        self.piece_by_track[track_id]["temperature"] = temperature

    def set_nb_bars_generated(self, n_bars=8):  # default is a 8 bar model
        self.model_n_bar = n_bars

    """ Generation Tools - Dictionnaries """

    def initiate_track_dict(self, instr, density, temperature):
        label = len(self.piece_by_track)
        self.piece_by_track.append(
            {
                "label": f"track_{label}",
                "instrument": instr,
                "density": density,
                "temperature": temperature,
                "bars": [],
            }
        )

    def update_track_dict__add_bars(self, bars, track_id):
        """Add bars to the track dictionnary"""
        for bar in self.striping_track_ends(bars).split("BAR_START "):
            if bar == "":  # happens is there is one bar only
                continue
            else:
                if "TRACK_START" in bar:
                    self.piece_by_track[track_id]["bars"].append(bar)
                else:
                    self.piece_by_track[track_id]["bars"].append("BAR_START " + bar)

    def get_all_instr_bars(self, track_id):
        return self.piece_by_track[track_id]["bars"]

    def striping_track_ends(self, text):
        if "TRACK_END" in text:
            # first get rid of extra space if any
            # then gets rid of "TRACK_END"
            text = text.rstrip(" ").rstrip("TRACK_END")
        return text

    def get_last_generated_track(self, piece):
        """Get the last track from a piece written as a single long string"""
        track = self.get_tracks_from_a_piece(piece)[-1]
        return track

    def get_tracks_from_a_piece(self, piece):
        """Get all the tracks from a piece written as a single long string"""
        all_tracks = [
            "TRACK_START " + the_track + "TRACK_END "
            for the_track in self.striping_track_ends(piece.split("TRACK_START ")[1::])
        ]
        return all_tracks

    def get_piece_from_track_list(self, track_list):
        piece = "PIECE_START "
        for track in track_list:
            piece += track
        return piece

    def get_whole_track_from_bar_dict(self, track_id):
        text = ""
        for bar in self.piece_by_track[track_id]["bars"]:
            text += bar
        text += "TRACK_END "
        return text

    @staticmethod
    def get_newly_generated_text(input_prompt, full_piece):
        return full_piece[len(input_prompt) :]

    def get_whole_piece_from_bar_dict(self):
        text = "PIECE_START "
        for track_id, _ in enumerate(self.piece_by_track):
            text += self.get_whole_track_from_bar_dict(track_id)
        return text

    def delete_one_track(self, track):
        self.piece_by_track.pop(track)

    """Basic generation tools"""

    def tokenize_input_prompt(self, input_prompt, verbose=True):
        """Tokenizing prompt

        Args:
        - input_prompt (str): prompt to tokenize

        Returns:
        - input_prompt_ids (torch.tensor): tokenized prompt
        """
        if verbose:
            print("Tokenizing input_prompt...")

        return self.tokenizer.encode(input_prompt, return_tensors="pt")

    def generate_sequence_of_token_ids(
        self,
        input_prompt_ids,
        temperature,
        verbose=True,
    ):
        """
        generate a sequence of token ids based on input_prompt_ids
        The sequence length depends on the trained model (self.model_n_bar)
        """
        generated_ids = self.model.generate(
            input_prompt_ids,
            max_length=self.max_length,
            do_sample=True,
            temperature=temperature,
            no_repeat_ngram_size=self.no_repeat_ngram_size,  # default = 0
            eos_token_id=self.tokenizer.encode(self.generate_until)[0],  # good
        )

        if verbose:
            print("Generating a token_id sequence...")

        return generated_ids

    def convert_ids_to_text(self, generated_ids, verbose=True):
        """converts the token_ids to text"""
        generated_text = self.tokenizer.decode(generated_ids[0])
        if verbose:
            print("Converting token sequence to MidiText...")
        return generated_text

    def generate_until_track_end(
        self,
        input_prompt="PIECE_START ",
        instrument=None,
        density=None,
        temperature=None,
        verbose=True,
        expected_length=None,
    ):
        """generate until the TRACK_END token is reached
        full_piece = input_prompt + generated"""
        if expected_length is None:
            expected_length = self.model_n_bar

        if instrument is not None:
            input_prompt = f"{input_prompt}TRACK_START INST={str(instrument)} "
            if density is not None:
                input_prompt = f"{input_prompt}DENSITY={str(density)} "

        if instrument is None and density is not None:
            print("Density cannot be defined without an input_prompt instrument #TOFIX")

        if temperature is None:
            ValueError("Temperature must be defined")

        if verbose:
            print("--------------------")
            print(
                f"Generating {instrument} - Density {density} - temperature {temperature}"
            )
        bar_count_checks = False
        failed = 0
        while not bar_count_checks:  # regenerate until right length
            input_prompt_ids = self.tokenize_input_prompt(input_prompt, verbose=verbose)
            generated_tokens = self.generate_sequence_of_token_ids(
                input_prompt_ids, temperature, verbose=verbose
            )
            full_piece = self.convert_ids_to_text(generated_tokens, verbose=verbose)
            generated = self.get_newly_generated_text(input_prompt, full_piece)
            # bar_count_checks
            bar_count_checks, bar_count = bar_count_check(generated, expected_length)

            if not self.force_sequence_length:
                # set bar_count_checks to true to exist the while loop
                bar_count_checks = True

            if not bar_count_checks and self.force_sequence_length:
                # if the generated sequence is not the expected length
                if failed > -1:  # deactivated for speed
                    full_piece, bar_count_checks = forcing_bar_count(
                        input_prompt,
                        generated,
                        bar_count,
                        expected_length,
                    )
                else:
                    print('"--- Wrong length - Regenerating ---')

            if not bar_count_checks:
                failed += 1

            if failed > 2:
                bar_count_checks = True  # exit the while loop if failed too much

        return full_piece

    def generate_one_new_track(
        self,
        instrument,
        density,
        temperature,
        input_prompt="PIECE_START ",
    ):
        self.initiate_track_dict(instrument, density, temperature)
        full_piece = self.generate_until_track_end(
            input_prompt=input_prompt,
            instrument=instrument,
            density=density,
            temperature=temperature,
        )

        track = self.get_last_generated_track(full_piece)
        self.update_track_dict__add_bars(track, -1)
        full_piece = self.get_whole_piece_from_bar_dict()
        return full_piece

    """ Piece generation - Basics """

    def generate_piece(self, instrument_list, density_list, temperature_list):
        """generate a sequence with mutiple tracks

        Args:
            - inst_list sets the list of instruments and the the order of generation
            - density and
            - temperature are paired with inst_list

        Each track/intrument is generated based on a prompt which contains the previously generated track/instrument

        Returns:
        'generated_piece' which keeps track of the entire piece
        """

        generated_piece = "PIECE_START "
        for instrument, density, temperature in zip(
            instrument_list, density_list, temperature_list
        ):
            generated_piece = self.generate_one_new_track(
                instrument,
                density,
                temperature,
                input_prompt=generated_piece,
            )

        # generated_piece = self.get_whole_piece_from_bar_dict()
        self.check_the_piece_for_errors()
        return generated_piece

    """ Piece generation - Extra Bars """

    def process_prompt_for_next_bar(self, track_idx, verbose=True):
        """Processing the prompt for the model to generate one more bar only.
        The prompt containts:
                if not the first bar: the previous, already processed, bars of the track
                the bar initialization (ex: "TRACK_START INST=DRUMS DENSITY=2 ")
                the last (self.model_n_bar)-1 bars of the track
        Args:
            track_idx (int): the index of the track to be processed

        Returns:
            the processed prompt for generating the next bar
        """
        track = self.piece_by_track[track_idx]
        # for bars which are not the bar to prolong
        pre_promt = "PIECE_START "
        for i, othertrack in enumerate(self.piece_by_track):
            if i != track_idx:
                len_diff = len(othertrack["bars"]) - len(track["bars"])
                if len_diff > 0:
                    if verbose:
                        print(
                            f"Adding bars - {len(track['bars'][-self.model_n_bar :])} selected from SIDE track: {i} for prompt"
                        )
                    # if other bars are longer, it mean that this one should catch up
                    pre_promt += othertrack["bars"][0]
                    for bar in track["bars"][-self.model_n_bar :]:
                        pre_promt += bar
                    pre_promt += "TRACK_END "
                elif (
                    False
                ):  # len_diff <= 0: # THIS DOES NOT WORK - It just adds empty bars
                    # adding an empty bars at the end of the other tracks if they have not been processed yet
                    pre_promt += othertracks["bars"][0]
                    for bar in track["bars"][-(self.model_n_bar - 1) :]:
                        pre_promt += bar
                    for _ in range(abs(len_diff) + 1):
                        pre_promt += "BAR_START BAR_END "
                    pre_promt += "TRACK_END "

        # for the bar to prolong
        # initialization e.g TRACK_START INST=DRUMS DENSITY=2
        processed_prompt = track["bars"][0]
        if verbose:
            print(
                f"Adding bars - {len(track['bars'][-(self.model_n_bar - 1) :])} selected from MAIN track: {track_idx} for prompt"
            )
        for bar in track["bars"][-(self.model_n_bar - 1) :]:
            # adding the "last" bars of the track
            processed_prompt += bar

        processed_prompt += "BAR_START "

        # making the preprompt short enought to avoid bug due to length of the prompt (model limitation)
        pre_promt = self.force_prompt_length(pre_promt, 1500)

        print(
            f"--- prompt length = {len((pre_promt + processed_prompt).split(' '))} ---"
        )

        return pre_promt + processed_prompt

    def force_prompt_length(self, prompt, expected_length):
        """remove one instrument/track from the prompt it too long
        Args:
            prompt (str): the prompt to be processed
            expected_length (int): the expected length of the prompt
        Returns:
            the truncated prompt"""
        if len(prompt.split(" ")) < expected_length:
            truncated_prompt = prompt
        else:
            tracks = self.get_tracks_from_a_piece(prompt)
            selected_tracks = random.sample(tracks, len(tracks) - 1)
            truncated_prompt = self.get_piece_from_track_list(selected_tracks)
            print(f"Prompt too long - deleting one track")

        return truncated_prompt

    def generate_one_more_bar(self, track_index):
        """Generate one more bar from the input_prompt"""
        processed_prompt = self.process_prompt_for_next_bar(track_index)

        prompt_plus_bar = self.generate_until_track_end(
            input_prompt=processed_prompt,
            temperature=self.piece_by_track[track_index]["temperature"],
            expected_length=1,
            verbose=False,
        )
        added_bar = self.get_newly_generated_bar(prompt_plus_bar)
        self.update_track_dict__add_bars(added_bar, track_index)

    def get_newly_generated_bar(self, prompt_plus_bar):
        return "BAR_START " + self.striping_track_ends(
            prompt_plus_bar.split("BAR_START ")[-1]
        )

    def generate_n_more_bars(self, n_bars, only_this_track=None, verbose=True):
        """Generate n more bars from the input_prompt"""
        if only_this_track is None:
            only_this_track

        print(f"================== ")
        print(f"Adding {n_bars} more bars to the piece ")
        for bar_id in range(n_bars):
            print(f"----- added bar #{bar_id+1} --")
            for i, track in enumerate(self.piece_by_track):
                if only_this_track is None or i == only_this_track:
                    print(f"--------- {track['label']}")
                    self.generate_one_more_bar(i)
        self.check_the_piece_for_errors()

    def check_the_piece_for_errors(self, piece: str = None):
        if piece is None:
            piece = self.get_whole_piece_from_bar_dict()
        errors = []
        errors.append(
            [
                (token, id)
                for id, token in enumerate(piece.split(" "))
                if token not in self.tokenizer.vocab or token == "UNK"
            ]
        )
        if len(errors) > 0:
            # print(piece)
            for er in errors:
                er
                print(f"Token not found in the piece at {er[0][1]}: {er[0][0]}")
                print(piece.split(" ")[er[0][1] - 5 : er[0][1] + 5])


if __name__ == "__main__":
    pass