app/helpers.py

import json
import os
import random
from base64 import b64encode
from io import BytesIO
from pathlib import Path

import matplotlib.pyplot as plt
import numpy as np
import streamlit as st
from PIL import Image
from pydub import AudioSegment
from streamlit.runtime.scriptrunner import RerunData, RerunException
from streamlit.source_util import get_pages
from streamlit_player import st_player

extensions = ["mp3", "wav", "ogg", "flac"]  # we will look for all those file types.


def check_file_availability(url):
    exit_status = os.system(f"wget -o --spider {url}")
    return exit_status == 0


@st.cache_data(show_spinner=False)
def url_is_valid(url):
    if url.startswith("http") is False:
        st.error("URL should start with http or https.")
        return False
    elif url.split(".")[-1] not in extensions:
        st.error("Extension not supported.")
        return False
    try:
        return check_file_availability(url)
    except Exception:
        st.error("URL is not valid.")
        return False


@st.cache_data(show_spinner=False)
def load_audio_segment(path: str, format: str) -> AudioSegment:
    return AudioSegment.from_file(path, format=format)


@st.cache_data(show_spinner=False)
def plot_audio(_audio_segment: AudioSegment, max_y: float, *args, **kwargs) -> Image.Image:
    samples = _audio_segment.get_array_of_samples()
    arr = np.array(samples)

    fig, ax = plt.subplots(figsize=(10, 2))
    ax.plot(arr, linewidth=0.04)
    ax.set_axis_off()

    # Scale the plot based on max Y value
    ax.set_ylim(bottom=-max_y, top=max_y)

    # Set the background color to transparent
    fig.patch.set_alpha(0)
    ax.patch.set_alpha(0)

    buf = BytesIO()
    plt.savefig(buf, format="png", dpi=100, bbox_inches="tight")
    buf.seek(0)
    image = Image.open(buf)

    plt.close(fig)
    return image


@st.cache_data(show_spinner=False)
def load_list_of_songs(path="sample_songs.json"):
    if os.environ.get("PREPARE_SAMPLES"):
        return json.load(open(path))
    else:
        st.error(
            "No examples available. You need to set the environment variable `PREPARE_SAMPLES=true`"
        )


def get_random_song():
    sample_songs = load_list_of_songs()
    if sample_songs is None:
        return None, None
    name, url = random.choice(list(sample_songs.items()))
    return name, url


def streamlit_player(
    player,
    url,
    height,
    is_active,
    muted,
    start,
    key,
    playback_rate=1,
    events=None,
    play_inline=False,
    light=False,
):
    with player:
        options = {
            "progress_interval": 1000,
            "playing": is_active,  # st.checkbox("Playing", False),
            "muted": muted,
            "light": light,
            "play_inline": play_inline,
            "playback_rate": playback_rate,
            "height": height,
            "config": {"start": start},
            "events": events,
        }
        if url != "":
            events = st_player(url, **options, key=key)
    return events


@st.cache_data(show_spinner=False)
def local_audio(path, mime="audio/mp3"):
    data = b64encode(Path(path).read_bytes()).decode()
    return [{"type": mime, "src": f"data:{mime};base64,{data}"}]


def _standardize_name(name: str) -> str:
    return name.lower().replace("_", " ").strip()


@st.cache_data(show_spinner=False)
def switch_page(page_name: str):
    st.session_state.page = page_name

    page_name = _standardize_name(page_name)

    pages = get_pages("header.py")  # OR whatever your main page is called

    for page_hash, config in pages.items():
        if _standardize_name(config["page_name"]) == page_name:
            raise RerunException(
                RerunData(
                    page_script_hash=page_hash,
                    page_name=page_name,
                )
            )

    page_names = [_standardize_name(config["page_name"]) for config in pages.values()]
    raise ValueError(f"Could not find page {page_name}. Must be one of {page_names}")


def st_local_audio(pathname, key):
    st_player(
        local_audio(pathname),
        **{
            "progress_interval": 1000,
            "playing": False,
            "muted": False,
            "light": False,
            "play_inline": True,
            "playback_rate": 1,
            "height": 40,
            "config": {"start": 0, "forceAudio": True, "forceHLS": True, "forceSafariHLS": True},
        },
        key=key,
    )