import argparse
import glob
import json
import os
import time

import gradio as gr
import numpy as np
import torch

import torch.nn.functional as F
import tqdm

import MIDI
from midi_model import MIDIModel
from midi_tokenizer import MIDITokenizer
from midi_synthesizer import synthesis
from huggingface_hub import hf_hub_download

MAX_SEED = np.iinfo(np.int32).max
in_space = os.getenv("SYSTEM") == "spaces"


@torch.inference_mode()
def generate(model, prompt=None, max_len=512, temp=1.0, top_p=0.98, top_k=20,
             disable_patch_change=False, disable_control_change=False, disable_channels=None, amp=True, generator=None):
    if disable_channels is not None:
        disable_channels = [tokenizer.parameter_ids["channel"][c] for c in disable_channels]
    else:
        disable_channels = []
    max_token_seq = tokenizer.max_token_seq
    if prompt is None:
        input_tensor = torch.full((1, max_token_seq), tokenizer.pad_id, dtype=torch.long, device=model.device)
        input_tensor[0, 0] = tokenizer.bos_id  # bos
    else:
        prompt = prompt[:, :max_token_seq]
        if prompt.shape[-1] < max_token_seq:
            prompt = np.pad(prompt, ((0, 0), (0, max_token_seq - prompt.shape[-1])),
                            mode="constant", constant_values=tokenizer.pad_id)
        input_tensor = torch.from_numpy(prompt).to(dtype=torch.long, device=model.device)
    input_tensor = input_tensor.unsqueeze(0)
    cur_len = input_tensor.shape[1]
    bar = tqdm.tqdm(desc="generating", total=max_len - cur_len, disable=in_space)
    with bar, torch.amp.autocast(device_type=model.device, enabled=amp):
        while cur_len < max_len:
            end = False
            hidden = model.forward(input_tensor)[0, -1].unsqueeze(0)
            next_token_seq = None
            event_name = ""
            for i in range(max_token_seq):
                mask = torch.zeros(tokenizer.vocab_size, dtype=torch.int64, device=model.device)
                if i == 0:
                    mask_ids = list(tokenizer.event_ids.values()) + [tokenizer.eos_id]
                    if disable_patch_change:
                        mask_ids.remove(tokenizer.event_ids["patch_change"])
                    if disable_control_change:
                        mask_ids.remove(tokenizer.event_ids["control_change"])
                    mask[mask_ids] = 1
                else:
                    param_name = tokenizer.events[event_name][i - 1]
                    mask_ids = tokenizer.parameter_ids[param_name]
                    if param_name == "channel":
                        mask_ids = [i for i in mask_ids if i not in disable_channels]
                    mask[mask_ids] = 1
                logits = model.forward_token(hidden, next_token_seq)[:, -1:]
                scores = torch.softmax(logits / temp, dim=-1) * mask
                sample = model.sample_top_p_k(scores, top_p, top_k, generator=generator)
                if i == 0:
                    next_token_seq = sample
                    eid = sample.item()
                    if eid == tokenizer.eos_id:
                        end = True
                        break
                    event_name = tokenizer.id_events[eid]
                else:
                    next_token_seq = torch.cat([next_token_seq, sample], dim=1)
                    if len(tokenizer.events[event_name]) == i:
                        break
            if next_token_seq.shape[1] < max_token_seq:
                next_token_seq = F.pad(next_token_seq, (0, max_token_seq - next_token_seq.shape[1]),
                                       "constant", value=tokenizer.pad_id)
            next_token_seq = next_token_seq.unsqueeze(1)
            input_tensor = torch.cat([input_tensor, next_token_seq], dim=1)
            cur_len += 1
            bar.update(1)
            yield next_token_seq.reshape(-1).cpu().numpy()
            if end:
                break


def create_msg(name, data):
    return {"name": name, "data": data}


def send_msgs(msgs):
    return json.dumps(msgs)


def run(model_name, tab, instruments, drum_kit, bpm, mid, midi_events, midi_opt, seed, seed_rand,
        gen_events, temp, top_p, top_k, allow_cc):
    mid_seq = []
    bpm = int(bpm)
    gen_events = int(gen_events)
    max_len = gen_events
    if seed_rand:
        seed = np.random.randint(0, MAX_SEED)
    generator = torch.Generator(device).manual_seed(seed)
    disable_patch_change = False
    disable_channels = None
    if tab == 0:
        i = 0
        mid = [[tokenizer.bos_id] + [tokenizer.pad_id] * (tokenizer.max_token_seq - 1)]
        if bpm != 0:
            mid.append(tokenizer.event2tokens(["set_tempo",0,0,0, bpm]))
        patches = {}
        if instruments is None:
            instruments = []
        for instr in instruments:
            patches[i] = patch2number[instr]
            i = (i + 1) if i != 8 else 10
        if drum_kit != "None":
            patches[9] = drum_kits2number[drum_kit]
        for i, (c, p) in enumerate(patches.items()):
            mid.append(tokenizer.event2tokens(["patch_change", 0, 0, i, c, p]))
        mid_seq = mid
        mid = np.asarray(mid, dtype=np.int64)
        if len(instruments) > 0:
            disable_patch_change = True
            disable_channels = [i for i in range(16) if i not in patches]
    elif mid is not None:
        eps = 4 if midi_opt else 0
        mid = tokenizer.tokenize(MIDI.midi2score(mid), cc_eps=eps, tempo_eps=eps)
        mid = np.asarray(mid, dtype=np.int64)
        mid = mid[:int(midi_events)]
        for token_seq in mid:
            mid_seq.append(token_seq.tolist())
    max_len += len(mid)

    events = [tokenizer.tokens2event(tokens) for tokens in mid_seq]
    init_msgs = [create_msg("visualizer_clear", None), create_msg("visualizer_append", events)]
    t = time.time() + 1
    yield mid_seq, None, None, seed, send_msgs(init_msgs)
    model = models[model_name]
    amp = device == "cuda"
    midi_generator = generate(model, mid, max_len=max_len, temp=temp, top_p=top_p, top_k=top_k,
                         disable_patch_change=disable_patch_change, disable_control_change=not allow_cc,
                         disable_channels=disable_channels, amp=amp, generator=generator)
    events = []
    for i, token_seq in enumerate(midi_generator):
        token_seq = token_seq.tolist()
        mid_seq.append(token_seq)
        events.append(tokenizer.tokens2event(token_seq))
        ct = time.time()
        if ct - t > 0.5:
            yield mid_seq, None, None, seed, send_msgs([create_msg("visualizer_append", events), create_msg("progress", [i + 1, gen_events])])
            t = ct
            events = []

    mid = tokenizer.detokenize(mid_seq)
    with open(f"output.mid", 'wb') as f:
        f.write(MIDI.score2midi(mid))
    audio = synthesis(MIDI.score2opus(mid), soundfont_path)
    events = [tokenizer.tokens2event(tokens) for tokens in mid_seq]
    yield mid_seq, "output.mid", (44100, audio), seed, send_msgs([create_msg("visualizer_end", events)])


def cancel_run(mid_seq):
    if mid_seq is None:
        return None, None, []
    mid = tokenizer.detokenize(mid_seq)
    with open(f"output.mid", 'wb') as f:
        f.write(MIDI.score2midi(mid))
    audio = synthesis(MIDI.score2opus(mid), soundfont_path)
    events = [tokenizer.tokens2event(tokens) for tokens in mid_seq]
    return "output.mid", (44100, audio), send_msgs([create_msg("visualizer_end", events)])


def load_javascript(dir="javascript"):
    scripts_list = glob.glob(f"{dir}/*.js")
    javascript = ""
    for path in scripts_list:
        with open(path, "r", encoding="utf8") as jsfile:
            javascript += f"\n<!-- {path} --><script>{jsfile.read()}</script>"
    template_response_ori = gr.routes.templates.TemplateResponse

    def template_response(*args, **kwargs):
        res = template_response_ori(*args, **kwargs)
        res.body = res.body.replace(
            b'</head>', f'{javascript}</head>'.encode("utf8"))
        res.init_headers()
        return res

    gr.routes.templates.TemplateResponse = template_response


def hf_hub_download_retry(repo_id, filename):
    print(f"downloading {repo_id} {filename}")
    retry = 0
    err = None
    while retry < 30:
        try:
            return hf_hub_download(repo_id=repo_id, filename=filename)
        except Exception as e:
            err = e
            retry += 1
    if err:
        raise err

number2drum_kits = {-1: "None", 0: "Standard", 8: "Room", 16: "Power", 24: "Electric", 25: "TR-808", 32: "Jazz",
                    40: "Blush", 48: "Orchestra"}
patch2number = {v: k for k, v in MIDI.Number2patch.items()}
drum_kits2number = {v: k for k, v in number2drum_kits.items()}

if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("--share", action="store_true", default=False, help="share gradio app")
    parser.add_argument("--port", type=int, default=7860, help="gradio server port")
    parser.add_argument("--max-gen", type=int, default=1024, help="max")
    opt = parser.parse_args()
    soundfont_path = hf_hub_download_retry(repo_id="skytnt/midi-model", filename="soundfont.sf2")
    models_info = {"generic pretrain model": ["skytnt/midi-model", ""],
                   "j-pop finetune model": ["skytnt/midi-model-ft", "jpop/"],
                   "touhou finetune model": ["skytnt/midi-model-ft", "touhou/"],
                   }
    device = "cuda" if torch.cuda.is_available() else "cpu"
    if device=="cuda": # flash attn
        torch.backends.cuda.enable_mem_efficient_sdp(True)
        torch.backends.cuda.enable_flash_sdp(True)
    models = {}
    tokenizer = MIDITokenizer()
    for name, (repo_id, path) in models_info.items():

        model_path = hf_hub_download_retry(repo_id=repo_id, filename=f"{path}model.ckpt")
        model = MIDIModel(tokenizer).to(device=device)
        ckpt = torch.load(model_path, weights_only=True)
        state_dict = ckpt.get("state_dict", ckpt)
        model.load_state_dict(state_dict, strict=False)
        model.eval()
        models[name] = model

    load_javascript()
    app = gr.Blocks()
    with app:
        gr.Markdown("<h1 style='text-align: center; margin-bottom: 1rem'>Midi Composer</h1>")
        gr.Markdown("![Visitors](https://api.visitorbadge.io/api/visitors?path=skytnt.midi-composer&style=flat)\n\n"
                    "Midi event transformer for music generation\n\n"
                    "Demo for [SkyTNT/midi-model](https://github.com/SkyTNT/midi-model)\n\n"
                    "[Open In Colab]"
                    "(https://colab.research.google.com/github/SkyTNT/midi-model/blob/main/demo.ipynb)"
                    " for faster running and longer generation\n\n"
                    "**Update v1.2**: Optimise the tokenizer and dataset\n\n"
                    f"Device: {device}"
                    )
        js_msg = gr.Textbox(elem_id="msg_receiver", visible=False)
        js_msg.change(None, [js_msg], [], js="""
        (msg_json) =>{
            let msgs = JSON.parse(msg_json);
            executeCallbacks(msgReceiveCallbacks, msgs);
            return [];
        }
        """)
        input_model = gr.Dropdown(label="select model", choices=list(models.keys()),
                                  type="value", value=list(models.keys())[0])
        tab_select = gr.State(value=0)
        with gr.Tabs():
            with gr.TabItem("instrument prompt") as tab1:
                input_instruments = gr.Dropdown(label="🪗instruments (auto if empty)", choices=list(patch2number.keys()),
                                                multiselect=True, max_choices=15, type="value")
                input_drum_kit = gr.Dropdown(label="🥁drum kit", choices=list(drum_kits2number.keys()), type="value",
                                             value="None")
                input_bpm = gr.Slider(label="BPM (beats per minute, auto if 0)", minimum=0, maximum=255,
                                              step=1,
                                              value=0)
                example1 = gr.Examples([
                    [[], "None"],
                    [["Acoustic Grand"], "None"],
                    [['Acoustic Grand', 'SynthStrings 2', 'SynthStrings 1', 'Pizzicato Strings',
                      'Pad 2 (warm)', 'Tremolo Strings', 'String Ensemble 1'], "Orchestra"],
                    [['Trumpet', 'Oboe', 'Trombone', 'String Ensemble 1', 'Clarinet',
                      'French Horn', 'Pad 4 (choir)', 'Bassoon', 'Flute'], "None"],
                    [['Flute', 'French Horn', 'Clarinet', 'String Ensemble 2', 'English Horn', 'Bassoon',
                      'Oboe', 'Pizzicato Strings'], "Orchestra"],
                    [['Electric Piano 2', 'Lead 5 (charang)', 'Electric Bass(pick)', 'Lead 2 (sawtooth)',
                      'Pad 1 (new age)', 'Orchestra Hit', 'Cello', 'Electric Guitar(clean)'], "Standard"],
                    [["Electric Guitar(clean)", "Electric Guitar(muted)", "Overdriven Guitar", "Distortion Guitar",
                      "Electric Bass(finger)"], "Standard"]
                ], [input_instruments, input_drum_kit])
            with gr.TabItem("midi prompt") as tab2:
                input_midi = gr.File(label="input midi", file_types=[".midi", ".mid"], type="binary")
                input_midi_events = gr.Slider(label="use first n midi events as prompt", minimum=1, maximum=512,
                                              step=1,
                                              value=128)
                input_midi_opt = gr.Checkbox(label="optimise midi (uncheck if your midi is generate from this model)", value=True)
                example2 = gr.Examples([[file, 128] for file in glob.glob("example/*.mid")],
                                       [input_midi, input_midi_events])

        tab1.select(lambda: 0, None, tab_select, queue=False)
        tab2.select(lambda: 1, None, tab_select, queue=False)
        input_seed = gr.Slider(label="seed", minimum=0, maximum=2 ** 31 - 1,
                               step=1, value=0)
        input_seed_rand = gr.Checkbox(label="random seed", value=True)
        input_gen_events = gr.Slider(label="generate max n midi events", minimum=1, maximum=opt.max_gen,
                                     step=1, value=opt.max_gen // 2)
        with gr.Accordion("options", open=False):
            input_temp = gr.Slider(label="temperature", minimum=0.1, maximum=1.2, step=0.01, value=1)
            input_top_p = gr.Slider(label="top p", minimum=0.1, maximum=1, step=0.01, value=0.98)
            input_top_k = gr.Slider(label="top k", minimum=1, maximum=128, step=1, value=10)
            input_allow_cc = gr.Checkbox(label="allow midi cc event", value=True)
            example3 = gr.Examples([[1, 0.98, 20], [1, 0.98, 12]], [input_temp, input_top_p, input_top_k])
        run_btn = gr.Button("generate", variant="primary")
        stop_btn = gr.Button("stop and output")
        output_midi_seq = gr.State()
        output_midi_visualizer = gr.HTML(elem_id="midi_visualizer_container")
        output_audio = gr.Audio(label="output audio", format="mp3", elem_id="midi_audio")
        output_midi = gr.File(label="output midi", file_types=[".mid"])
        run_event = run_btn.click(run, [input_model, tab_select, input_instruments, input_drum_kit, input_bpm,
                                        input_midi, input_midi_events, input_midi_opt, input_seed, input_seed_rand,
                                        input_gen_events, input_temp, input_top_p, input_top_k, input_allow_cc],
                                  [output_midi_seq, output_midi, output_audio, input_seed, js_msg],
                                  concurrency_limit=3)
        stop_btn.click(cancel_run, [output_midi_seq], [output_midi, output_audio, js_msg], cancels=run_event, queue=False)
    app.launch(server_port=opt.port, share=opt.share, inbrowser=True)