#!/usr/bin/env python3

import wave
import seaborn as sns
import pandas as pd
from matplotlib import pyplot as plt
from sys import argv

CAPTURE_FILE = argv[1]


def read_wav(wav_file):
    wav = wave.open(wav_file)
    timestamps = []
    values = []  # as floats uwu

    num_frames = wav.getnframes()
    samp_rate = wav.getframerate()
    samp_width = wav.getsampwidth()

    for i in range(0, num_frames):
        timestamp_seconds = i / samp_rate
        timestamp_microseconds = 1000 * 1000 * timestamp_seconds
        timestamps.append(timestamp_microseconds)

        value = wav.readframes(1)
        value_int = int.from_bytes(value, byteorder="little", signed=True)
        value_float = value_int / 2 ** (8 * samp_width)
        values.append(value_float)

    return pd.DataFrame(
        {
            "timestamp": timestamps,
            "value": values,
        }
    )


def main():
    df = read_wav(CAPTURE_FILE)

    # eeever so slightly clean up high-frequent-ish noise
    mean = df.rolling(window=5).mean()
    df["value"] = mean["value"]

    # convert to binary signal
    df["high"] = df["value"] > 0

    # create a list of durations of high pulses
    prev_state = False
    t_last_change = 0
    t_last_high = 0
    high_durations = []
    for _, row in df.iterrows():
        state = bool(row["high"])
        if state != prev_state:
            if state:  # rising edge
                t_last_change = row["timestamp"]
            else:  # falling edge
                duration = row["timestamp"] - t_last_change
                high_durations.append(duration)
        if state:
            t_last_high = row["timestamp"]
        elif (row["timestamp"] - t_last_high) > 1200:
            if len(high_durations) > 0 and high_durations[-1] > 0:
                high_durations.append(-1)  # long silence
        prev_state = state

    # sns.histplot([d for d in high_durations if d > 50 and d < 1200], bins=100)
    # plt.show()

    short = 200  # us
    long = 800  # us
    epsilon = 50  # us

    # print decoded packets to stdout:
    #   short high pulse -> `1`
    #   long high pulse -> `0`
    #   silence in between -> `\n`
    i = 0
    for duration in high_durations:
        if duration < 0:
            print()
        if abs(duration - short) < epsilon:
            print("1", end="")
        if abs(duration - long) < epsilon:
            print("0", end="")
        i += 1


if __name__ == "__main__":
    main()