import numpy as np
import soundfile as sf
from scipy.signal import lfilter, fftconvolve

# Global Parameters
sample_rate = 44100
duration_seconds = 30
samples = duration_seconds * sample_rate
t = np.linspace(0, duration_seconds, samples, endpoint=False)

# === 1. Aggressive White Noise + Reverb ===
def aggressive_white_noise():
    noise = np.random.normal(0, 0.07, samples)

    # High-pass filter
    b = [0.95, -0.95]
    a = [1, -0.85]
    filtered_noise = lfilter(b, a, noise)

    # Reverb via impulse response (short decaying tail)
    impulse_response = np.exp(-np.linspace(0, 1.5, int(0.3 * sample_rate)))
    impulse_response = impulse_response * np.random.uniform(0.8, 1.2, impulse_response.shape)
    reverb_noise = fftconvolve(filtered_noise, impulse_response, mode='full')[:samples]

    return reverb_noise

white_noise = aggressive_white_noise()

# === 3. Metallic Sonar Ping with Echo ===
def generate_sonar_ping(start_time, freq=5000, ping_duration=0.82):
    ping_t = np.linspace(0, ping_duration, int(sample_rate * ping_duration), endpoint=False)

    # FM modulation for metallic texture
    mod_freq = 1000 # Modulating frequency
    fm_wave = np.sin(2 * np.pi * freq * ping_t + 5 * np.sin(2 * np.pi * mod_freq * ping_t))

    envelope = np.exp(-8 * ping_t)
    ping = fm_wave * envelope * 0.6

    mod_freq = 4000 # Modulating frequency
    fm_wave = np.sin(2 * np.pi * freq * ping_t + 5 * np.sin(2 * np.pi * mod_freq * ping_t))

    envelope = np.exp(-8 * ping_t)
    ping = fm_wave * envelope * 0.9

    mod_freq = 7000 # Modulating frequency
    fm_wave = np.sin(2 * np.pi * freq * ping_t + 5 * np.sin(2 * np.pi * mod_freq * ping_t))

    envelope = np.exp(-8 * ping_t)
    ping = fm_wave * envelope * 0.5

    # Add echo (delay)
    echo_delay = int(0.01 * sample_rate)
    echo = np.pad(ping * 0.1, (echo_delay, 0), 'constant')[:len(ping)]
    ping = ping + echo
    echo_delay = int(0.06 * sample_rate)
    echo = np.pad(ping * 0.1, (echo_delay, 0), 'constant')[:len(ping)]
    ping = ping + echo
    echo_delay = int(0.06 * sample_rate)
    echo = np.pad(ping * 0.1, (echo_delay, 0), 'constant')[:len(ping)]
    ping = ping + echo
    echo_delay = int(0.1 * sample_rate)
    echo = np.pad(ping * 0.1, (echo_delay, 0), 'constant')[:len(ping)]
    ping = ping + echo
    echo_delay = int(0.2 * sample_rate)
    echo = np.pad(ping * 0.1, (echo_delay, 0), 'constant')[:len(ping)]
    ping = ping + echo




    sonar = np.zeros(samples)
    start_sample = int(start_time * sample_rate)
    end_sample = start_sample + len(ping)
    if end_sample <= samples:
        sonar[start_sample:end_sample] = ping
    return sonar

sonar_total = np.zeros(samples)
np.random.seed(42)
ping_times = np.cumsum(np.random.uniform(0.5, 3.0, size=12))
ping_times = ping_times[ping_times < duration_seconds]
for pt in ping_times:
    sonar_total += generate_sonar_ping(pt)

# === 4. Combine & Normalize ===
final_mix = 0.2*white_noise  + 3.0*sonar_total
final_mix = final_mix / np.max(np.abs(final_mix))

# === 5. Export ===
file_path = 'test.wav'
sf.write(file_path, final_mix, sample_rate)
print(f"✅ Saved to: {file_path}")