use std::{
  io::{self, stdout},
  sync::{
    Arc, Mutex,
    atomic::{AtomicBool, Ordering},
    mpsc,
  },
  thread,
  time::Duration,
};

use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
use crossterm::{
  ExecutableCommand,
  event::{self, Event, KeyCode, KeyModifiers},
  terminal::{EnterAlternateScreen, LeaveAlternateScreen, disable_raw_mode, enable_raw_mode},
};

use figlet_rs::Toilet;
use notify_rust::Notification;
use ratatui::{
  Frame, Terminal,
  backend::CrosstermBackend,
  layout::{Alignment, Constraint, Direction, Layout, Rect},
  style::{Color, Style},
  widgets::{Block, Borders, Clear, Paragraph},
};
use realfft::{RealFftPlanner, num_complex};

const SECONDS_PER_MIN: u32 = 60;

#[derive(Debug, PartialEq, Eq, Clone, Copy)]
enum TimerMode {
  Work,
  Break,
}

fn send_desktop_notification(title: &str, body: &str) {
  let title = title.to_string();
  let body = body.to_string();

  std::thread::spawn(move || {
    let _ = Notification::new()
      .summary(&title)
      .body(&body)
      .appname("termato")
      .show();
  });
}

struct Termato {
  work_mins: u32,
  break_mins: u32,
  mode: TimerMode,
  is_running: bool,
  duration_in_secs: u32,
  time_remaining_in_sec: u32,
  show_help: bool,
  enable_notifications: bool,
  enable_visualizer: bool,
}

impl Termato {
  fn new(work_mins: u32, break_mins: u32) -> Self {
    Termato {
      work_mins,
      break_mins,
      mode: TimerMode::Work,
      is_running: false,
      duration_in_secs: work_mins * SECONDS_PER_MIN,
      time_remaining_in_sec: work_mins * SECONDS_PER_MIN,
      show_help: false,
      enable_notifications: false,
      enable_visualizer: false,
    }
  }

  fn with_notifications(mut self, enable: bool) -> Self {
    self.enable_notifications = enable;
    self
  }

  fn with_visualizer(mut self, enable: bool) -> Self {
    self.enable_visualizer = enable;
    self
  }

  fn toggle_running(&mut self) {
    self.is_running = !self.is_running;
  }

  fn toggle_mode(&mut self) {
    self.mode = match self.mode {
      TimerMode::Work => TimerMode::Break,
      TimerMode::Break => TimerMode::Work,
    };
    self.duration_in_secs = match self.mode {
      TimerMode::Work => self.work_mins * SECONDS_PER_MIN,
      TimerMode::Break => self.break_mins * SECONDS_PER_MIN,
    };
    self.time_remaining_in_sec = self.duration_in_secs;
  }

  fn tick(&mut self) {
    if self.is_running && self.time_remaining_in_sec > 0 {
      self.time_remaining_in_sec -= 1;

      if self.time_remaining_in_sec == 0 {
        if self.enable_notifications {
          match self.mode {
            TimerMode::Work => send_desktop_notification("Work Done", "Time to take a break."),
            TimerMode::Break => send_desktop_notification("Break Over", "Time to focus."),
          }
        }

        self.toggle_mode();
      }
    }
  }

  fn reset(&mut self) {
    self.is_running = false;
    self.mode = TimerMode::Work;
    self.duration_in_secs = self.work_mins * SECONDS_PER_MIN;
    self.time_remaining_in_sec = self.duration_in_secs;
  }

  fn toggle_help(&mut self) {
    self.show_help = !self.show_help;
  }
}

struct TerminalGuard;

impl TerminalGuard {
  fn new() -> Result<Self, io::Error> {
    enable_raw_mode()?;
    stdout().execute(EnterAlternateScreen)?;
    Ok(TerminalGuard)
  }
}

impl Drop for TerminalGuard {
  fn drop(&mut self) {
    let _ = disable_raw_mode();
    let _ = stdout().execute(LeaveAlternateScreen);
  }
}

struct AudioVisualizer {
  bar_data: Arc<Mutex<Vec<u64>>>,
  stop_flag: Arc<AtomicBool>,
}

// This is a implementation largely lifted from these
// open source implementation. I just wrote it in Rust here:
// 1. CAVA (C): https://github.com/karlstav/cava
// 2. cli-visualizer (C++): https://github.com/dpayne/cli-visualizer
impl AudioVisualizer {
  fn new(num_bars: usize) -> Self {
    let bar_data = Arc::new(Mutex::new(vec![0; num_bars]));
    let bar_data_clone = Arc::clone(&bar_data);
    let stop_flag = Arc::new(AtomicBool::new(false));
    let stop_clone = Arc::clone(&stop_flag);

    thread::spawn(move || {
      if let Err(e) = Self::run_audio_loop(bar_data_clone, num_bars, stop_clone) {
        eprintln!("Audio capture error: {:?}", e);
      }
    });

    Self {
      bar_data,
      stop_flag,
    }
  }

  // Doing best effort to support cross-platform functionality
  fn get_audio_device(
    host: &cpal::Host,
  ) -> Result<(cpal::Device, cpal::StreamConfig), Box<dyn std::error::Error>> {
    // Try windows WASAPI loopback on default output device
    #[cfg(target_os = "windows")]
    {
      if let Some(device) = host.default_output_device()
        && let Ok(config) = device.default_output_config()
      {
        return Ok((device, config.into()));
      }
    }

    // Try Linux PipeWire/PulseAudio output monitor device
    #[cfg(target_os = "linux")]
    {
      if let Ok(devices) = host.devices() {
        for dev in devices {
          if let Ok(name) = dev.name() {
            // Monitor devices mirror system output under PulseAudio/PipeWire
            if name.contains("monitor") {
              if let Ok(config) = dev.default_input_config() {
                return Ok((dev, config.into()));
              }
            }
          }
        }
      }
    }

    // Fallback to default input device
    let device = host
      .default_input_device()
      .or_else(|| host.default_output_device())
      .ok_or("No audio input or output device found")?;

    let config = device
      .default_input_config()
      .or_else(|_| device.default_output_config())?
      .into();

    Ok((device, config))
  }

  // we here in doubling octaves but fft outputs linearly spaced bins.
  // so we bundle bins on a log scale from 20 hz to 12 kHz
  // this allows bass, mids, and trembls to have equal visual
  // proportions during display
  //
  // i.e.
  // bins like this [0-500Hz] [500-1k] [1k-1.5k] [1.5k-2k] [2k-2.5k] [2.5k-3k] [3k-12kHz]
  //   vs
  // bins like this [20-60Hz] [60-250Hz] [250-500Hz] [500-2kHz] [2k-4kHz] [4k-8kHz] [8k-12kHz]
  fn build_log_bins(num_bars: usize, sample_rate: f32, chunk_size: usize) -> Vec<(usize, usize)> {
    let nyquist = sample_rate / 2.0;
    let max_hz = 12000.0f32;

    (0..num_bars)
      .map(|i| {
        let low_hz = 20.0 * (max_hz / 20.0).powf(i as f32 / num_bars as f32);
        let high_hz = 20.0 * (max_hz / 20.0).powf((i + 1) as f32 / num_bars as f32);

        let low = ((low_hz / nyquist) * (chunk_size as f32 / 2.0)) as usize;
        let high = ((high_hz / nyquist) * (chunk_size as f32 / 2.0)) as usize;

        (low.max(1), high.max(low + 1))
      })
      .collect()
  }

  // without we get sharp edges which gives noise in FFT processing
  fn apply_hann_window(samples: &[f32], input_buffer: &mut [f32]) {
    let chunk_size = samples.len();

    for (i, sample) in samples.iter().enumerate() {
      let window = 0.5 * (1.0 - (2.0 * std::f32::consts::PI * i as f32 / chunk_size as f32).cos());
      input_buffer[i] = sample * window;
    }
  }

  fn process_fft_magnitudes(
    spectrum: &[num_complex::Complex32],
    log_bins: &[(usize, usize)],
    freq_boost: &[f32],
    prev_heights: &[f32],
    autosens: f32,
    smoothing: f32,
    falloff: f32,
  ) -> Vec<f32> {
    let num_bars = log_bins.len();
    let mut current_bars = vec![0.0f32; num_bars];

    // determine magnitude
    for i in 0..num_bars {
      let (start, stop) = log_bins[i];
      let bin_slice = &spectrum[start..stop.min(spectrum.len())];
      let magnitude_sum: f32 = bin_slice.iter().map(|c| c.norm()).sum();
      let avg_mag = if !bin_slice.is_empty() {
        magnitude_sum / bin_slice.len() as f32
      } else {
        0.0
      };

      // ignore quiet static noise below specific amplitude
      let raw_val = if avg_mag < 0.02 {
        0.0
      } else {
        (avg_mag * freq_boost[i] * autosens + 1.0).log10() * 3.5
      };

      // rise smoothly from previous height
      let target = (raw_val * (1.0 - smoothing)) + (prev_heights[i] * smoothing);

      // prevent sudden drops
      if target < prev_heights[i] {
        current_bars[i] = (prev_heights[i] - falloff).max(0.0);
      } else {
        current_bars[i] = target;
      }
    }

    current_bars
  }

  // blend the heights between neighboring freq bins
  // so instead of sharp spikes we get more of waves
  fn apply_monstercat_smoothing(bars: &[f32]) -> Vec<f32> {
    let num_bars = bars.len();
    let mut smoothed = bars.to_vec();

    for i in 1..(num_bars - 1) {
      smoothed[i] = (bars[i - 1] * 0.25) + (bars[i] * 0.50) + (bars[i + 1] * 0.25);
    }

    smoothed
  }

  // songs can be quiet and loud so we try to adjust
  // sensitivity to avoid bars becoming flattened or
  // clipped
  fn adjust_autosens(autosens: &mut f32, bars: &[f32]) {
    let max_val = bars.iter().copied().fold(0.0f32, f32::max);

    if max_val > 8.0 {
      *autosens *= 0.98;
    } else if max_val < 3.0 && *autosens < 3.0 {
      *autosens *= 1.01;
    }
  }

  // captures output and runs through pipeline
  // system audio -> audio buffer -> windowing -> fft process -> binning -> floor/autosens -> smoothing
  fn run_audio_loop(
    bar_data: Arc<Mutex<Vec<u64>>>,
    num_bars: usize,
    stop: Arc<AtomicBool>,
  ) -> Result<(), Box<dyn std::error::Error>> {
    let host = cpal::default_host();
    let (device, config) = Self::get_audio_device(&host)?;

    let sample_rate = config.sample_rate as f32;
    let channels = config.channels as usize;

    let chunk_size = 2048;
    let mut planner = RealFftPlanner::<f32>::new();
    let fft = planner.plan_fft_forward(chunk_size);
    let mut windowed_buffer = fft.make_input_vec();
    let mut spectrum = fft.make_output_vec();

    let mut prev_heights = vec![0.0f32; num_bars];
    let smoothing = 0.70f32;
    let falloff = 0.08f32;
    let mut autosens = 1.0f32;

    let log_bins = Self::build_log_bins(num_bars, sample_rate, chunk_size);

    // high freq have less amplitude so we boost
    // more and more as we go right
    let freq_boost: Vec<f32> = (0..num_bars)
      .map(|i| 1.0 + (3.5 * (i as f32 / num_bars as f32).powf(1.2)))
      .collect();

    let audio_buffer = Arc::new(Mutex::new(Vec::<f32>::with_capacity(chunk_size * 2)));
    let buffer_clone = Arc::clone(&audio_buffer);

    let stream = device.build_input_stream(
      config,
      move |data: &[f32], _| {
        if let Ok(mut buf) = buffer_clone.lock() {
          for chunk in data.chunks(channels) {
            let mono: f32 = chunk.iter().sum::<f32>() / channels as f32;
            buf.push(mono);
          }

          if buf.len() > chunk_size * 2 {
            let drain_amt = buf.len() - chunk_size;
            buf.drain(0..drain_amt);
          }
        }
      },
      |err| eprintln!("Stream error: {}", err),
      None,
    )?;

    stream.play()?;

    while !stop.load(Ordering::Relaxed) {
      thread::sleep(std::time::Duration::from_millis(16));

      let samples = {
        let buf = match audio_buffer.lock() {
          Ok(b) => b,
          Err(_) => continue,
        };
        if buf.len() < chunk_size {
          continue;
        }
        buf[buf.len() - chunk_size..].to_vec()
      };

      Self::apply_hann_window(&samples, &mut windowed_buffer);

      if let Err(e) = fft.process(&mut windowed_buffer, &mut spectrum) {
        eprintln!("FFT error: {:?}", e);
        continue;
      }

      let raw_bars = Self::process_fft_magnitudes(
        &spectrum,
        &log_bins,
        &freq_boost,
        &prev_heights,
        autosens,
        smoothing,
        falloff,
      );

      let smoothed_bars = Self::apply_monstercat_smoothing(&raw_bars);
      prev_heights = smoothed_bars.clone();

      Self::adjust_autosens(&mut autosens, &smoothed_bars);

      if let Ok(mut bars) = bar_data.lock() {
        for (i, val) in smoothed_bars.iter().enumerate() {
          bars[i] = ((*val * 10.0).clamp(0.0, 100.0)) as u64;
        }
      }
    }

    Ok(())
  }
}

impl Drop for AudioVisualizer {
  fn drop(&mut self) {
    self.stop_flag.store(true, Ordering::Relaxed);
  }
}

// use unicode blocks for rendering
// Empty        -> " "
// 1/8th height -> "▂"
// 2/8th height -> "▃"
// 3/8th height -> "▄"
// 4/8th height -> "▅"
// 5/8th height -> "▆"
// 6/8th height -> "▇"
// Full Height  -> "█"
fn render_visualizer(f: &mut Frame, area: Rect, bar_values: &[u64]) {
  const BLOCKS: [&str; 8] = ["▂", "▃", "▄", "▅", "▆", "▇", "█", "█"];

  let max_bars = area.width as usize;
  let line: String = bar_values
    .iter()
    .take(max_bars)
    .map(|&val| {
      if val == 0 {
        " "
      } else {
        let idx = ((val as f32 / 100.0) * (BLOCKS.len() - 1) as f32)
          .clamp(0.0, (BLOCKS.len() - 1) as f32) as usize;

        BLOCKS[idx]
      }
    })
    .collect();

  let viz_paragraph = Paragraph::new(line)
    .style(Style::default().fg(Color::Rgb(200, 184, 224)))
    .alignment(Alignment::Center);

  f.render_widget(viz_paragraph, area);
}

// TODO: Refactor to an Elm like architecture
fn main() -> Result<(), io::Error> {
  let args: Vec<String> = std::env::args().collect();

  if args.iter().any(|arg| arg == "-h" || arg == "--help") {
    println!("Usage: termato [options] [work_minutes] [break_minutes]");
    println!();
    println!("Options:");
    println!("  -n, --notify      Enable desktop notifications");
    println!("  -h, --help        Print this help message");
    println!("  -v, --version     Print the version number");
    println!("  -z, --visualizer  Display visualizer of playing audio");
    println!();
    println!("Defaults: work_minutes = 25, break_minutes = 5");
    return Ok(());
  }

  if args.iter().any(|arg| arg == "-v" || arg == "--version") {
    println!("termato version {}", env!("CARGO_PKG_VERSION"));
    return Ok(());
  }

  let _guard = TerminalGuard::new()?;

  let backend = CrosstermBackend::new(stdout());
  let mut terminal = Terminal::new(backend)?;
  let font = Toilet::smblock().unwrap();

  let enable_visualizer = args.iter().any(|arg| arg == "-z" || arg == "--visualizer");
  let enable_notifications = args.iter().any(|arg| arg == "-n" || arg == "--notify");

  let visualizer = if enable_visualizer {
    Some(AudioVisualizer::new(64))
  } else {
    None
  };

  let is_flag = |arg: &str| {
    arg == "-n"
      || arg == "--notify"
      || arg == "-z"
      || arg == "--visualizer"
      || arg == "-h"
      || arg == "--help"
      || arg == "-v"
      || arg == "--version"
  };

  let positional_args: Vec<&String> = args.iter().skip(1).filter(|arg| !is_flag(arg)).collect();

  let work_mins = positional_args
    .first()
    .and_then(|s| s.parse().ok())
    .unwrap_or(25);

  let break_mins = positional_args
    .get(1)
    .and_then(|s| s.parse().ok())
    .unwrap_or(5);

  let mut termato = Termato::new(work_mins, break_mins)
    .with_notifications(enable_notifications)
    .with_visualizer(enable_visualizer);

  let (tx, rx) = mpsc::channel();

  thread::spawn(move || {
    loop {
      thread::sleep(Duration::from_secs(1));
      if tx.send(()).is_err() {
        break;
      }
    }
  });

  loop {
    terminal.draw(|f| {
      let size = f.area();

      let minutes = termato.time_remaining_in_sec / SECONDS_PER_MIN;
      let seconds = termato.time_remaining_in_sec % SECONDS_PER_MIN;
      let time_str = format!("{:02}:{:02}", minutes, seconds);

      let time_color = if !termato.is_running {
        Color::Rgb(212, 200, 122)
      } else {
        match termato.mode {
          TimerMode::Work => Color::Rgb(212, 115, 115),
          TimerMode::Break => Color::Rgb(126, 200, 192),
        }
      };

      let raw_time_text = if let Some(fig) = font.convert(&time_str) {
        fig.to_string()
      } else {
        time_str
      };

      let trimmed_time_text = raw_time_text.trim_matches('\n');
      let text_lines: Vec<&str> = trimmed_time_text.lines().collect();
      let text_height = text_lines.len() as u16;

      let viz_height = if visualizer.is_some() { 1 } else { 0 };
      let viz_width = 64;

      let content_height = text_height + viz_height;

      let outer_vertical = Layout::default()
        .direction(Direction::Vertical)
        .constraints([
          Constraint::Min(0),
          Constraint::Length(content_height),
          Constraint::Min(0),
        ])
        .split(size);

      let inner_vertical = Layout::default()
        .direction(Direction::Vertical)
        .constraints([
          Constraint::Length(text_height),
          Constraint::Length(viz_height),
        ])
        .split(outer_vertical[1]);

      let viz_horizontal = Layout::default()
        .direction(Direction::Horizontal)
        .constraints([
          Constraint::Min(0),
          Constraint::Length(viz_width.min(size.width)),
          Constraint::Min(0),
        ])
        .split(inner_vertical[1]);

      let timer_paragraph = Paragraph::new(trimmed_time_text)
        .style(Style::default().fg(time_color))
        .alignment(Alignment::Center);

      f.render_widget(timer_paragraph, inner_vertical[0]);

      if let Some(ref viz) = visualizer
        && let Ok(bar_data) = viz.bar_data.lock()
      {
        render_visualizer(f, viz_horizontal[1], &bar_data);
      }

      if termato.show_help {
        let popup_width = 44;
        let popup_height = 7;

        if size.width >= popup_width && size.height >= popup_height {
          let popup_vertical = Layout::default()
            .direction(Direction::Vertical)
            .constraints([
              Constraint::Length((size.height.saturating_sub(popup_height)) / 2),
              Constraint::Length(popup_height),
              Constraint::Min(1),
            ])
            .split(size);

          let popup_horizontal = Layout::default()
            .direction(Direction::Horizontal)
            .constraints([
              Constraint::Length((size.width.saturating_sub(popup_width)) / 2),
              Constraint::Length(popup_width),
              Constraint::Min(1),
            ])
            .split(popup_vertical[1]);

          let popup_area = popup_horizontal[1];

          let help_block = Block::default()
            .title(" Controls ")
            .borders(Borders::ALL)
            .border_style(Style::default().fg(Color::Rgb(58, 62, 70)));

          let help_content = Paragraph::new(
            "[Space] Pause / Resume\n\
             [S]     Switch Mode\n\
             [R]     Reset Timer\n\
             [?]     Toggle Help\n\
             [Q]     Quit",
          )
          .block(help_block)
          .style(Style::default().fg(Color::Rgb(224, 228, 232)))
          .alignment(Alignment::Left);

          f.render_widget(Clear, popup_area);
          f.render_widget(help_content, popup_area);
        }
      }
    })?;

    if event::poll(Duration::from_millis(16))?
      && let Event::Key(key) = event::read()?
      && key.kind == event::KeyEventKind::Press
    {
      match key.code {
        KeyCode::Char('q') | KeyCode::Char('Q') => break,
        KeyCode::Char('c') if key.modifiers.contains(KeyModifiers::CONTROL) => break,
        KeyCode::Char(' ') => termato.toggle_running(),
        KeyCode::Char('s') | KeyCode::Char('S') => termato.toggle_mode(),
        KeyCode::Char('r') | KeyCode::Char('R') => termato.reset(),
        KeyCode::Char('?') => termato.toggle_help(),
        _ => {}
      }
    }

    if rx.try_recv().is_ok() {
      termato.tick();
    }
  }

  Ok(())
}

#[cfg(test)]
mod tests {
  use super::*;

  #[test]
  fn termato_new_when_called_it_should_return_expected_starting_state() {
    let result = Termato::new(25, 5);

    assert_eq!(result.work_mins, 25);
    assert_eq!(result.break_mins, 5);
    assert_eq!(result.mode, TimerMode::Work);
    assert!(!result.is_running);
    assert_eq!(result.duration_in_secs, 1500);
    assert_eq!(result.time_remaining_in_sec, 1500);
    assert!(!result.show_help);
    assert!(!result.enable_notifications);
    assert!(!result.enable_visualizer);
  }

  #[test]
  fn termato_tick_when_called_and_not_running_it_should_do_nothing() {
    let mut termato = Termato::new(1, 1);

    termato.tick();

    assert_eq!(termato.time_remaining_in_sec, 60);
  }

  #[test]
  fn termato_tick_when_called_and_no_time_remaining_it_should_do_nothing() {
    let mut termato = Termato::new(1, 1);
    termato.is_running = true;
    termato.time_remaining_in_sec = 0;

    termato.tick();

    assert_eq!(termato.time_remaining_in_sec, 0);
  }

  #[test]
  fn termato_tick_when_running_and_time_reamining_it_should_reduce_remaining_by_one() {
    let mut termato = Termato::new(1, 1);
    termato.is_running = true;

    termato.tick();

    assert_eq!(termato.time_remaining_in_sec, 59);
  }

  #[test]
  fn termato_tick_when_running_on_work_and_time_remaining_reaches_zero_it_should_toggle_to_break() {
    let mut termato = Termato::new(1, 2);
    termato.is_running = true;
    termato.time_remaining_in_sec = 1;

    termato.tick();

    assert_eq!(termato.mode, TimerMode::Break);
    assert_eq!(termato.duration_in_secs, 120);
    assert_eq!(termato.time_remaining_in_sec, 120);
  }

  #[test]
  fn termato_tick_when_running_on_break_and_time_remaining_reaches_zero_it_should_toggle_to_work() {
    let mut termato = Termato::new(2, 1);
    termato.mode = TimerMode::Break;
    termato.is_running = true;
    termato.time_remaining_in_sec = 1;

    termato.tick();

    assert_eq!(termato.mode, TimerMode::Work);
    assert_eq!(termato.duration_in_secs, 120);
    assert_eq!(termato.time_remaining_in_sec, 120);
  }

  #[test]
  fn termato_toggle_mode_when_called_it_should_toggle_the_mode() {
    let mut termato = Termato::new(2, 1);

    termato.toggle_mode();
    assert_eq!(termato.mode, TimerMode::Break);
    assert_eq!(termato.duration_in_secs, 60);
    assert_eq!(termato.time_remaining_in_sec, 60);

    termato.toggle_mode();
    assert_eq!(termato.mode, TimerMode::Work);
    assert_eq!(termato.duration_in_secs, 120);
    assert_eq!(termato.time_remaining_in_sec, 120);
  }

  #[test]
  fn termato_toggle_running_when_called_and_already_running_it_should_pause() {
    let mut termato = Termato::new(1, 1);
    termato.is_running = true;

    termato.toggle_running();

    assert!(!termato.is_running)
  }

  #[test]
  fn termato_toggle_running_when_called_and_already_paused_it_should_run() {
    let mut termato = Termato::new(1, 1);

    termato.toggle_running();

    assert!(termato.is_running)
  }

  #[test]
  fn termato_rest_when_called_it_should_reset_the_apps_state() {
    let mut termato = Termato::new(1, 1);
    termato.is_running = true;
    termato.mode = TimerMode::Break;
    termato.duration_in_secs = 1;
    termato.time_remaining_in_sec = 1;

    termato.reset();

    assert!(!termato.is_running);
    assert_eq!(termato.mode, TimerMode::Work);
    assert_eq!(termato.duration_in_secs, 60);
    assert_eq!(termato.time_remaining_in_sec, 60);
  }

  #[test]
  fn termato_toggle_help_when_called_it_should_toggle_help() {
    let mut termato = Termato::new(1, 1);

    termato.toggle_help();

    assert!(termato.show_help);

    termato.toggle_help();

    assert!(!termato.show_help);
  }

  #[test]
  fn termato_notifications_when_called_it_should_verify_opt_in_behavior() {
    let result = Termato::new(25, 5);
    assert!(!result.enable_notifications);

    let result = result.with_notifications(true);
    assert!(result.enable_notifications);
  }

  #[test]
  fn termato_visualizer_when_called_it_should_verify_opt_in_behavior() {
    let result = Termato::new(25, 5);
    assert!(!result.enable_visualizer);

    let result = result.with_visualizer(true);
    assert!(result.enable_visualizer);
  }
}