import os
import sys
from math import pi, sin, tanh

from keyboard import setup_term
from pyalsa import Alsa

SAMPLE_RATE = 44_100
LATENCY = 50_000  # 50ms
INT16_MAX = 2**15 - 1
alsa = Alsa(SAMPLE_RATE, LATENCY)

keys = "azertyuiop"
gain = 0.5
base_freq = 440.0
freqs = [0.0] * len(keys)
phases = [0.0] * len(keys)
mix_mode = "voice_count"
buf_size = 512


def tanh_mix(voices, gain):
    sample = tanh(gain * sum(voices))  # apply tanh with gain (soft clipping)
    return sample


def voice_count_mix(voices, gain):
    sample = sum(voices) / len(voices)  # normalize to [0, 1] range
    sample = sample * gain
    return sample


def clamp(x, a, b):
    return max(a, min(b, x))


os.set_blocking(sys.stdin.fileno(), False)
with setup_term():
    while True:
        buf = [0] * buf_size
        for i in range(buf_size):
            voices = [0.0] * len(keys)
            for j in range(len(keys)):
                phase, freq = phases[j], freqs[j]
                if freq == 0:
                    continue
                voices[j] = sin(phase)
                phases[j] += 2 * pi * freq / SAMPLE_RATE

            if voices == []:
                continue

            # mixing
            mixfn = tanh_mix if mix_mode == "tanh" else voice_count_mix
            mix = int(mixfn(voices, gain) * INT16_MAX)
            buf[i] = clamp(
                mix, -INT16_MAX - 1, INT16_MAX
            )  # final clamp to int16 range, just in case
        alsa.write(buf)  # this is blocking

        # input handling
        key = sys.stdin.read(1)
        if key == "q":
            break
        elif key == " ":
            mix_mode = "tanh" if mix_mode == "voice_count" else "voice_count"
            print(mix_mode)
        elif key is not None and key != "" and key in keys:
            i = keys.index(key)
            if freqs[i] == 0:
                freqs[i] = base_freq * (2 ** (i / 12))
            else:
                freqs[i] = 0