feat: implement timer module (#118)

Implement a timer module that takes a commandline argument, the number of seconds the last job took to complete, and displays it if appropriate.

Alters shell initialization files to compute this number using date +%s where needed.

Adds a config section to configure minimum amount of time before timer is shown (default is 2s)

src/modules/cmd_duration.rs

@@ -0,0 +1,90 @@
+use crate::config::Config;
+use ansi_term::Color;
+
+use super::{Context, Module};
+
+/// Outputs the time it took the last command to execute
+///
+/// Will only print if last command took more than a certain amount of time to
+/// execute. Default is two seconds, but can be set by config option `min_time`.
+pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
+    let mut module = context.new_module("cmd_duration")?;
+
+    let arguments = &context.arguments;
+    let elapsed = arguments
+        .value_of("cmd_duration")
+        .unwrap_or("invalid_time")
+        .parse::<u64>()
+        .ok()?;
+
+    let signed_config_min = module.config_value_i64("min_time").unwrap_or(2);
+
+    /* TODO: Once error handling is implemented, warn the user if their config
+    min time is nonsensical */
+    if signed_config_min < 0 {
+        log::debug!(
+            "[WARN]: min_time in [cmd_duration] ({}) was less than zero",
+            signed_config_min
+        );
+        return None;
+    }
+
+    let config_min = signed_config_min as u64;
+
+    let module_color = match elapsed {
+        time if time < config_min => return None,
+        _ => Color::Yellow.bold(),
+    };
+
+    module.set_style(module_color);
+    module.new_segment("cmd_duration", &format!("took {}", render_time(elapsed)));
+    module.get_prefix().set_value("");
+
+    Some(module)
+}
+
+// Render the time into a nice human-readable string
+fn render_time(raw_seconds: u64) -> String {
+    // Calculate a simple breakdown into days/hours/minutes/seconds
+    let (seconds, raw_minutes) = (raw_seconds % 60, raw_seconds / 60);
+    let (minutes, raw_hours) = (raw_minutes % 60, raw_minutes / 60);
+    let (hours, days) = (raw_hours % 24, raw_hours / 24);
+
+    let components = [days, hours, minutes, seconds];
+    let suffixes = ["d", "h", "m", "s"];
+
+    let rendered_components: Vec<String> = components
+        .iter()
+        .zip(&suffixes)
+        .map(render_time_component)
+        .collect();
+    rendered_components.join("")
+}
+
+/// Render a single component of the time string, giving an empty string if component is zero
+fn render_time_component((component, suffix): (&u64, &&str)) -> String {
+    match component {
+        0 => String::new(),
+        n => format!("{}{}", n, suffix),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_10s() {
+        assert_eq!(render_time(10 as u64), "10s")
+    }
+    fn test_90s() {
+        assert_eq!(render_time(90 as u64), "1m30s")
+    }
+    fn test_10110s() {
+        assert_eq!(render_time(10110 as u64), "1h48m30s")
+    }
+    fn test_1d() {
+        assert_eq!(render_time(86400 as u64), "1d")
+    }
+
+}

src/modules/mod.rs

@@ -1,5 +1,6 @@
 mod battery;
 mod character;
+mod cmd_duration;
 mod directory;
 mod git_branch;
 mod git_status;
@@ -28,6 +29,7 @@ pub fn handle<'a>(module: &str, context: &'a Context) -> Option<Module<'a>> {
         "git_status" => git_status::module(context),
         "username" => username::module(context),
         "battery" => battery::module(context),
+        "cmd_duration" => cmd_duration::module(context),
 
         _ => panic!("Unknown module: {}", module),
     }