#!/usr/bin/env bash

# Check if SoX is installed; exit if it is not found
if ! command -v play &> /dev/null; then
    echo "Error: SoX is not installed. Please install it first (e.g., sudo apt install sox)."
    exit 1
fi

# Set default playback duration
DURATION="15:00"

while true; do
    clear
    echo "========================================================="
    echo "       Advanced Therapeutic Frequency Generator          "
    echo "========================================================="
    echo "--- Standard Pure Tones ---"
    echo "1) 40 Hz Gamma Tone"
    echo "   Benefit: Promotes advanced cognitive processing and focus."
    echo ""
    echo "2) 8 Hz Alpha Binaural Beat (Requires Headphones)"
    echo "   Benefit: Reduces anxiety (200Hz Left / 208Hz Right)."
    echo ""
    echo "3) 5 Hz Theta Binaural Beat (Requires Headphones)"
    echo "   Benefit: Encourages deep meditative states and sleep"
    echo "            preparation (200Hz Left / 205Hz Right)."
    echo ""
    echo "--- Complex Modulations & Variable Beats ---"
    echo "4) Ascending Binaural Sweep: Theta to Beta (Requires Headphones)"
    echo "   Benefit: Gently shifts the brain from a relaxed meditative"
    echo "            state (5 Hz difference) into a sharp, focused state"
    echo "            (15 Hz difference) over the full duration."
    echo ""
    echo "5) 174 Hz Isochronic Healing Pulse (No Headphones Needed)"
    echo "   Benefit: Uses an aggressive 7 Hz volume modulation (tremolo)"
    echo "            over a 174 Hz base tone. Often used for physical"
    echo "            tension reduction and pain relief."
    echo ""
    echo "6) 432 Hz Atmospheric Modulated Drone"
    echo "   Benefit: Combines slow amplitude modulation, phase shifting,"
    echo "            and heavy reverb. Prevents auditory fatigue and"
    echo "            creates a dynamic, evolving soundscape for deep work."
    echo ""
    echo "7) Slow-Rolling Brown Noise 'Ocean' Modulations"
    echo "   Benefit: Filters brown noise with a slow amplitude sweep."
    echo "            Acts as an acoustic blanket to mask background"
    echo "            distractions or tinnitus."
    echo ""
    echo "0) Exit"
    echo "========================================================="
    
    read -p "Select an option [0-7]: " choice
    
    echo ""
    
    case $choice in
        1)
            echo "Playing 40 Hz Gamma Tone for $DURATION. Press Ctrl+C to stop."
            play -n synth $DURATION sine 40
            ;;
        2)
            echo "Playing 8 Hz Alpha Binaural Beat for $DURATION. Press Ctrl+C to stop."
            play -n synth $DURATION sine 200 sine 208 remix 1 2
            ;;
        3)
            echo "Playing 5 Hz Theta Binaural Beat for $DURATION. Press Ctrl+C to stop early."
            play -n synth $DURATION sine 200 sine 205 remix 1 2
            ;;  
        4)
            echo "Playing Ascending Binaural Sweep for $DURATION. Press Ctrl+C to stop."
            # Left stays at 200. Right sweeps linearly from 205 to 215.
            play -n synth $DURATION sine 200 sine 205-215 remix 1 2
            ;;
        5)
            echo "Playing 174 Hz Isochronic Pulse for $DURATION. Press Ctrl+C to stop."
            # tremolo speed=7Hz, depth=100% (creates the hard pulse effect)
            play -n synth $DURATION sine 174 tremolo 7 100
            ;;
        6)
            echo "Playing Modulated 432 Hz Drone for $DURATION. Press Ctrl+C to stop."
            # Adds slow tremolo (0.15Hz), a phaser for movement, and 50% reverb
            play -n synth $DURATION sine 432 tremolo 0.15 40 phaser 0.9 0.85 4 0.23 1 -s reverb 50
            ;;
        7)
            echo "Playing Brown Noise Ocean Modulations for $DURATION. Press Ctrl+C to stop."
            # bandpass filter around 400Hz, slow tremolo (0.1Hz at 60% depth), and reverb
            play -n synth $DURATION brownnoise band -n 400 400 tremolo 0.1 60 reverb 50
            ;;
        0)
            echo "Exiting..."
            exit 0
            ;;
        *)
            echo "Invalid selection. Please press Enter to try again."
            read -r
            ;;
    esac
    
    echo ""
    read -p "Playback finished or stopped. Press Enter to return to the menu..."
done