src/app.rs

@@ -0,0 +1,271 @@
+use crate::constants::SECONDS_PER_MIN;
+use crate::msg::Message;
+use crate::notification::send_desktop_notification;
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum TimerMode {
+  Work,
+  Break,
+}
+
+pub struct Termato {
+  pub work_mins: u32,
+  pub break_mins: u32,
+  pub mode: TimerMode,
+  pub is_running: bool,
+  pub duration_in_secs: u32,
+  pub time_remaining_in_sec: u32,
+  pub show_help: bool,
+  pub enable_notifications: bool,
+  should_quit: bool,
+}
+
+impl Termato {
+  pub 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,
+      should_quit: false,
+    }
+  }
+
+  pub fn should_quit(&self) -> bool {
+    self.should_quit
+  }
+
+  pub fn with_notifications(mut self, enable: bool) -> Self {
+    self.enable_notifications = enable;
+    self
+  }
+
+  pub fn update(&mut self, msg: Message) {
+    match msg {
+      Message::Tick => self.tick(),
+      Message::ToggleRunning => self.toggle_running(),
+      Message::ToggleMode => self.toggle_mode(),
+      Message::Reset => self.reset(),
+      Message::ToggleHelp => self.toggle_help(),
+      Message::Quit => self.should_quit = true,
+    }
+  }
+
+  pub fn toggle_running(&mut self) {
+    self.is_running = !self.is_running;
+  }
+
+  pub 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;
+  }
+
+  pub 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();
+      }
+    }
+  }
+
+  pub 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;
+  }
+
+  pub fn toggle_help(&mut self) {
+    self.show_help = !self.show_help;
+  }
+}
+
+#[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.should_quit);
+  }
+
+  #[test]
+  fn termato_update_when_called_with_messages_it_should_update_state() {
+    let mut termato = Termato::new(25, 5);
+
+    termato.update(Message::ToggleRunning);
+    assert!(termato.is_running);
+
+    termato.update(Message::ToggleHelp);
+    assert!(termato.show_help);
+
+    termato.update(Message::ToggleMode);
+    assert_eq!(termato.mode, TimerMode::Break);
+
+    termato.update(Message::Reset);
+    assert!(!termato.is_running);
+    assert_eq!(termato.mode, TimerMode::Work);
+
+    termato.update(Message::Quit);
+    assert!(termato.should_quit);
+  }
+
+  #[test]
+  fn termato_tick_when_called_and_not_running_it_should_do_nothing() {
+    let mut termato = Termato::new(1, 1);
+
+    termato.update(Message::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.update(Message::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.update(Message::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.update(Message::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.update(Message::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);
+  }
+}

src/args.rs

@@ -0,0 +1,201 @@
+use std::env;
+
+use crate::constants::{DEFAULT_BREAK_MINS, DEFAULT_WORK_MINS};
+
+pub const FLAG_HELP: &str = "-h";
+pub const FLAG_HELP_LONG: &str = "--help";
+pub const FLAG_VERSION: &str = "-v";
+pub const FLAG_VERSION_LONG: &str = "--version";
+pub const FLAG_NOTIFY: &str = "-n";
+pub const FLAG_NOTIFY_LONG: &str = "--notify";
+pub const FLAG_VISUALIZER: &str = "-z";
+pub const FLAG_VISUALIZER_LONG: &str = "--visualizer";
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct CliConfig {
+  pub work_mins: u32,
+  pub break_mins: u32,
+  pub enable_notifications: bool,
+  pub enable_visualizer: bool,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum CliAction {
+  Run(CliConfig),
+  PrintHelp,
+  PrintVersion,
+  Error(String),
+}
+
+pub struct Cli;
+
+impl Cli {
+  pub fn parse() -> CliAction {
+    Self::parse_args(env::args().collect())
+  }
+
+  pub fn parse_args(args: Vec<String>) -> CliAction {
+    let mut enable_notifications = false;
+    let mut enable_visualizer = false;
+    let mut positional = Vec::new();
+
+    for arg in args.into_iter().skip(1) {
+      match arg.as_str() {
+        FLAG_HELP | FLAG_HELP_LONG => return CliAction::PrintHelp,
+        FLAG_VERSION | FLAG_VERSION_LONG => return CliAction::PrintVersion,
+        FLAG_NOTIFY | FLAG_NOTIFY_LONG => enable_notifications = true,
+        FLAG_VISUALIZER | FLAG_VISUALIZER_LONG => enable_visualizer = true,
+        "--" => {}
+        s if s.starts_with('-') => {
+          return CliAction::Error(format!("Unknown option: '{}'", s));
+        }
+        s => positional.push(s.to_string()),
+      }
+    }
+
+    let numbers: Vec<u32> = positional
+      .iter()
+      .filter_map(|s| s.parse::<u32>().ok())
+      .collect();
+
+    let work_mins = numbers.first().copied().unwrap_or(DEFAULT_WORK_MINS);
+    let break_mins = numbers.get(1).copied().unwrap_or(DEFAULT_BREAK_MINS);
+
+    if numbers.len() > 2 {
+      return CliAction::Error(format!("Unexpected argument: '{}'", positional[2]));
+    }
+
+    CliAction::Run(CliConfig {
+      work_mins,
+      break_mins,
+      enable_notifications,
+      enable_visualizer,
+    })
+  }
+
+  pub fn print_help() {
+    println!("Usage: termato [options] [work_minutes] [break_minutes]");
+
+    println!();
+
+    println!("Options:");
+
+    println!(
+      "  {:<19} Enable desktop notifications",
+      format_args!("{}, {}", FLAG_NOTIFY, FLAG_NOTIFY_LONG)
+    );
+
+    println!(
+      "  {:<19} Display visualizer of playing audio",
+      format_args!("{}, {}", FLAG_VISUALIZER, FLAG_VISUALIZER_LONG)
+    );
+
+    println!(
+      "  {:<19} Print this help message",
+      format_args!("{}, {}", FLAG_HELP, FLAG_HELP_LONG)
+    );
+
+    println!(
+      "  {:<19} Print the version number",
+      format_args!("{}, {}", FLAG_VERSION, FLAG_VERSION_LONG)
+    );
+
+    println!();
+
+    println!(
+      "Defaults: work_minutes = {}, break_minutes = {}",
+      DEFAULT_WORK_MINS, DEFAULT_BREAK_MINS
+    );
+  }
+
+  pub fn print_version() {
+    println!("termato version {}", env!("CARGO_PKG_VERSION"));
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn test_defaults() {
+    let args = vec!["termato".to_string()];
+    assert_eq!(
+      Cli::parse_args(args),
+      CliAction::Run(CliConfig {
+        work_mins: 25,
+        break_mins: 5,
+        enable_notifications: false,
+        enable_visualizer: false,
+      })
+    );
+  }
+
+  #[test]
+  fn test_cargo_run_syntax_with_dot_and_dash_dash() {
+    let args = vec![
+      "target/debug/termato.exe".to_string(),
+      ".".to_string(),
+      "--".to_string(),
+      "-z".to_string(),
+    ];
+    assert_eq!(
+      Cli::parse_args(args),
+      CliAction::Run(CliConfig {
+        work_mins: 25,
+        break_mins: 5,
+        enable_notifications: false,
+        enable_visualizer: true,
+      })
+    );
+  }
+
+  #[test]
+  fn test_custom_time_and_flags() {
+    let args = vec![
+      "termato".to_string(),
+      "-n".to_string(),
+      "-z".to_string(),
+      "50".to_string(),
+      "10".to_string(),
+    ];
+    assert_eq!(
+      Cli::parse_args(args),
+      CliAction::Run(CliConfig {
+        work_mins: 50,
+        break_mins: 10,
+        enable_notifications: true,
+        enable_visualizer: true,
+      })
+    );
+  }
+
+  #[test]
+  fn test_help_flag() {
+    let args = vec!["termato".to_string(), "--help".to_string()];
+    assert_eq!(Cli::parse_args(args), CliAction::PrintHelp);
+  }
+
+  #[test]
+  fn test_unknown_flag() {
+    let args = vec!["termato".to_string(), "--foo".to_string()];
+    assert_eq!(
+      Cli::parse_args(args),
+      CliAction::Error("Unknown option: '--foo'".to_string())
+    );
+  }
+
+  #[test]
+  fn test_non_numeric_positional_defaults() {
+    let args = vec!["termato".to_string(), "abc".to_string()];
+    assert_eq!(
+      Cli::parse_args(args),
+      CliAction::Run(CliConfig {
+        work_mins: 25,
+        break_mins: 5,
+        enable_notifications: false,
+        enable_visualizer: false,
+      })
+    );
+  }
+}

src/audio.rs

@@ -0,0 +1,298 @@
+use std::{
+  sync::{
+    Arc, Mutex,
+    atomic::{AtomicBool, Ordering},
+  },
+  thread,
+};
+
+use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
+use realfft::{RealFftPlanner, num_complex};
+
+pub struct AudioVisualizer {
+  pub bar_data: Arc<Mutex<Vec<u64>>>,
+  pub 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 {
+  pub 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(desc) = dev.description() {
+            let name = desc.to_string();
+
+            // 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);
+
+    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);
+  }
+}

src/constants.rs

@@ -0,0 +1,4 @@
+pub const SECONDS_PER_MIN: u32 = 60;
+pub const DEFAULT_WORK_MINS: u32 = 25;
+pub const DEFAULT_BREAK_MINS: u32 = 5;
+pub const VIZ_NUM_BARS: u16 = 64;

src/events.rs

@@ -0,0 +1,38 @@
+use crossterm::event::{self, Event, KeyCode, KeyModifiers};
+use crate::msg::Message;
+
+pub fn handle_event(event: Event) -> Option<Message> {
+  if let Event::Key(key) = event
+    && key.kind == event::KeyEventKind::Press
+  {
+    match key.code {
+      KeyCode::Char('q') | KeyCode::Char('Q') => Some(Message::Quit),
+      KeyCode::Char('c') if key.modifiers.contains(KeyModifiers::CONTROL) => Some(Message::Quit),
+      KeyCode::Char(' ') => Some(Message::ToggleRunning),
+      KeyCode::Char('s') | KeyCode::Char('S') => Some(Message::ToggleMode),
+      KeyCode::Char('r') | KeyCode::Char('R') => Some(Message::Reset),
+      KeyCode::Char('?') => Some(Message::ToggleHelp),
+      _ => None,
+    }
+  } else {
+    None
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use crossterm::event::KeyEvent;
+
+  #[test]
+  fn handle_event_when_called_maps_key_presses_to_messages() {
+    let key_event = Event::Key(KeyEvent::new(KeyCode::Char(' '), KeyModifiers::NONE));
+    assert_eq!(handle_event(key_event), Some(Message::ToggleRunning));
+
+    let key_event_q = Event::Key(KeyEvent::new(KeyCode::Char('q'), KeyModifiers::NONE));
+    assert_eq!(handle_event(key_event_q), Some(Message::Quit));
+
+    let key_event_unknown = Event::Key(KeyEvent::new(KeyCode::Char('z'), KeyModifiers::NONE));
+    assert_eq!(handle_event(key_event_unknown), None);
+  }
+}

src/main.rs

@@ -1,498 +1,52 @@
+mod app;
+mod args;
+mod audio;
+mod constants;
+mod events;
+mod msg;
+mod notification;
+mod terminal;
+mod ui;
+
 use std::{
   io::{self, stdout},
-  sync::{
-    Arc, Mutex,
-    atomic::{AtomicBool, Ordering},
-    mpsc,
-  },
+  sync::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 crossterm::event;
 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};
+use ratatui::{Terminal, backend::CrosstermBackend};
 
-const SECONDS_PER_MIN: u32 = 60;
+use app::Termato;
+use audio::AudioVisualizer;
+use events::handle_event;
+use msg::Message;
+use terminal::TerminalGuard;
+use ui::render_app;
 
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-enum TimerMode {
-  Work,
-  Break,
-}
+use args::{Cli, CliAction};
 
-fn send_desktop_notification(title: &str, body: &str) {
-  let title = title.to_string();
-  let body = body.to_string();
+use crate::constants::VIZ_NUM_BARS;
 
-  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(desc) = dev.description() {
-            let name = desc.to_string();
-
-            if name.contains("monitor") {
-              // Monitor devices mirror system output under PulseAudio/PipeWire
-              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 config = match Cli::parse() {
+    CliAction::PrintHelp => {
+      Cli::print_help();
+      return Ok(());
+    }
+    CliAction::PrintVersion => {
+      Cli::print_version();
+      return Ok(());
+    }
+    CliAction::Error(err) => {
+      eprintln!("Error: {}", err);
+      eprintln!("Run 'termato --help' for usage instructions.");
+      std::process::exit(1);
+    }
+    CliAction::Run(cfg) => cfg,
+  };
 
   let _guard = TerminalGuard::new()?;
 
@@ -500,41 +54,14 @@ fn main() -> Result<(), io::Error> {
   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))
+  let visualizer = if config.enable_visualizer {
+    Some(AudioVisualizer::new(VIZ_NUM_BARS as usize))
   } 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 mut termato = Termato::new(config.work_mins, config.break_mins)
+    .with_notifications(config.enable_notifications);
 
   let (tx, rx) = mpsc::channel();
 
@@ -547,300 +74,20 @@ fn main() -> Result<(), io::Error> {
     }
   });
 
-  loop {
-    terminal.draw(|f| {
-      let size = f.area();
+  while !termato.should_quit() {
+    terminal.draw(|f| render_app(&termato, f, &font, visualizer.as_ref()))?;
 
-      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 event::poll(Duration::from_millis(16))? {
+      let raw_event = event::read()?;
+      if let Some(msg) = handle_event(raw_event) {
+        termato.update(msg);
       }
     }
 
     if rx.try_recv().is_ok() {
-      termato.tick();
+      termato.update(Message::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);
-  }
-}

src/msg.rs

@@ -0,0 +1,9 @@
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum Message {
+  Tick,
+  ToggleRunning,
+  ToggleMode,
+  Reset,
+  ToggleHelp,
+  Quit,
+}

src/notification.rs

@@ -0,0 +1,14 @@
+use notify_rust::Notification;
+
+pub 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();
+  });
+}

src/terminal.rs

@@ -0,0 +1,22 @@
+use crossterm::{
+  ExecutableCommand,
+  terminal::{EnterAlternateScreen, LeaveAlternateScreen, disable_raw_mode, enable_raw_mode},
+};
+use std::io::{self, stdout};
+
+pub struct TerminalGuard;
+
+impl TerminalGuard {
+  pub 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);
+  }
+}

src/ui.rs

@@ -0,0 +1,169 @@
+use figlet_rs::Toilet;
+use ratatui::{
+  Frame,
+  layout::{Alignment, Constraint, Direction, Layout, Rect},
+  style::{Color, Style},
+  widgets::{Block, Borders, Clear, Paragraph},
+};
+
+use crate::{audio::AudioVisualizer, constants::VIZ_NUM_BARS};
+use crate::{
+  app::{Termato, TimerMode},
+  constants::SECONDS_PER_MIN,
+};
+
+// 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  -> "█"
+pub 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);
+}
+
+pub fn render_app(
+  app: &Termato,
+  f: &mut Frame,
+  font: &Toilet,
+  visualizer: Option<&AudioVisualizer>,
+) {
+  let size = f.area();
+
+  let minutes = app.time_remaining_in_sec / SECONDS_PER_MIN;
+  let seconds = app.time_remaining_in_sec % SECONDS_PER_MIN;
+  let time_str = format!("{:02}:{:02}", minutes, seconds);
+
+  let time_color = if !app.is_running {
+    Color::Rgb(212, 200, 122)
+  } else {
+    match app.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 = VIZ_NUM_BARS;
+
+  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(viz) = visualizer
+    && let Ok(bar_data) = viz.bar_data.lock()
+  {
+    render_visualizer(f, viz_horizontal[1], &bar_data);
+  }
+
+  if app.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);
+    }
+  }
+}