From bc2c363a49b185a629e2ce145c7cd94631af9ab2 Mon Sep 17 00:00:00 2001
From: Clement Tsang <34804052+ClementTsang@users.noreply.github.com>
Date: Thu, 11 Jan 2024 00:25:53 -0500
Subject: refactor: clean up arg code more (#1377)

* fix sort function

* Try macros

* Revert "Try macros"

This reverts commit 93c7306f8ae8b906e0a66d1a4d758aad51efe3eb.

* use next_help_heading instead

* test

* Revert "test"

This reverts commit 017a1702b35dd7fd87c449e27a3bdb65bc858f72.

* Reapply "test"

This reverts commit 23c09d3828594d880ecf5e753e1fcdf5fd719e42.

* use foldl instead :)

* a word

* different conditionals

* update docs, change ordering

* more formatting stuff
---
 README.md                                          |   2 +-
 docs/content/configuration/command-line-flags.md   |  47 --
 docs/content/configuration/command-line-options.md |  94 +++
 docs/content/configuration/config-file/flags.md    |   2 +-
 docs/content/index.md                              |   2 +-
 docs/content/usage/widgets/network.md              |   2 +-
 docs/mkdocs.yml                                    |   2 +-
 src/options/args.rs                                | 871 ++++++++++-----------
 8 files changed, 506 insertions(+), 516 deletions(-)
 delete mode 100644 docs/content/configuration/command-line-flags.md
 create mode 100644 docs/content/configuration/command-line-options.md

diff --git a/README.md b/README.md
index 40b8865b..071d76a4 100644
--- a/README.md
+++ b/README.md
@@ -78,7 +78,7 @@ As (yet another) process/system visualization and management application, bottom
 
 - [Cross-platform support](https://github.com/ClementTsang/bottom#support) for Linux, macOS, and Windows, with more planned in the future.
 
-- [Customizable behaviour](https://clementtsang.github.io/bottom/nightly/configuration/command-line-flags/) that can be controlled with command-line flags or a config file, such as:
+- [Customizable behaviour](https://clementtsang.github.io/bottom/nightly/configuration/command-line-options/) that can be controlled with command-line flags or a config file, such as:
 
   - Custom and built-in colour themes
   - Customizing widget behaviour
diff --git a/docs/content/configuration/command-line-flags.md b/docs/content/configuration/command-line-flags.md
deleted file mode 100644
index e2ab53ae..00000000
--- a/docs/content/configuration/command-line-flags.md
+++ /dev/null
@@ -1,47 +0,0 @@
-# Command-line Flags
-
-The following flags can be provided to bottom in the command line to change the behaviour of the program. You can also
-see information on these flags by running `btm -h`, or run `btm --help` to display more detailed information on each flag:
-
-| Flag                                | Behaviour                                                             |
-| ----------------------------------- | --------------------------------------------------------------------- |
-| --autohide_time                     | Temporarily shows the time scale in graphs.                           |
-| -b, --basic                         | Hides graphs and uses a more basic look.                              |
-| --battery                           | Shows the battery widget.                                             |
-| -S, --case_sensitive                | Enables case sensitivity by default.                                  |
-| -c, --celsius                       | Sets the temperature type to Celsius.                                 |
-| --color <COLOR SCHEME>              | Use a color scheme, use --help for info.                              |
-| -C, --config <CONFIG PATH>          | Sets the location of the config file.                                 |
-| -u, --current_usage                 | Sets process CPU% to be based on current CPU%.                        |
-| -t, --default_time_value <TIME>     | Default time value for graphs.                                        |
-| --default_widget_count <INT>        | Sets the n'th selected widget type as the default.                    |
-| --default_widget_type <WIDGET TYPE> | Sets the default widget type, use --help for info.                    |
-| --disable_advanced_kill             | Hides advanced process killing.                                       |
-| --disable_click                     | Disables mouse clicks.                                                |
-| -m, --dot_marker                    | Uses a dot marker for graphs.                                         |
-| --enable_cache_memory               | Enable collecting and displaying cache and buffer memory.             |
-| --enable_gpu                        | Enable collecting and displaying GPU usage.                           |
-| -e, --expanded                      | Expand the default widget upon starting the app.                      |
-| -f, --fahrenheit                    | Sets the temperature type to Fahrenheit.                              |
-| -g, --group_processes               | Groups processes with the same name by default.                       |
-| -a, --hide_avg_cpu                  | Hides the average CPU usage.                                          |
-| --hide_table_gap                    | Hides spacing between table headers and entries.                      |
-| --hide_time                         | Hides the time scale.                                                 |
-| -k, --kelvin                        | Sets the temperature type to Kelvin.                                  |
-| -l, --left_legend                   | Puts the CPU chart legend to the left side.                           |
-| --mem_as_value                      | Defaults to showing process memory usage by value.                    |
-| --network_use_binary_prefix         | Displays the network widget with binary prefixes.                     |
-| --network_use_bytes                 | Displays the network widget using bytes.                              |
-| --network_use_log                   | Displays the network widget with a log scale.                         |
-| --process_command                   | Show processes as their commands by default.                          |
-| -r, --rate <TIME>                   | Sets the data refresh rate.                                           |
-| -R, --regex                         | Enables regex by default.                                             |
-| --retention <TIME>                  | The timespan of data stored.                                          |
-| --show_table_scroll_position        | Shows the scroll position tracker in table widgets.                   |
-| -d, --time_delta <TIME>             | The amount of time changed upon zooming.                              |
-| -T, --tree                          | Defaults the process widget be in tree mode.                          |
-| -n, --unnormalized_cpu              | Show process CPU% usage without normalizing over the number of cores. |
-| --use_old_network_legend            | DEPRECATED - uses a separate network legend.                          |
-| -V, --version                       | Prints version information.                                           |
-| -W, --whole_word                    | Enables whole-word matching by default.                               |
-| -h, --help                          | Print help (see more with '--help')                                   |
diff --git a/docs/content/configuration/command-line-options.md b/docs/content/configuration/command-line-options.md
new file mode 100644
index 00000000..2f3a2fd9
--- /dev/null
+++ b/docs/content/configuration/command-line-options.md
@@ -0,0 +1,94 @@
+# Command-line Options
+
+The following options can be provided to bottom in the command line to change the behaviour of the program. You can also
+see information on these options by running `btm -h`, or run `btm --help` to display more detailed information on each option:
+
+## General Options
+
+| Option                              | Behaviour                                           |
+| ----------------------------------- | --------------------------------------------------- |
+| --autohide_time                     | Temporarily shows the time scale in graphs.         |
+| -b, --basic                         | Hides graphs and uses a more basic look.            |
+| -C, --config <CONFIG PATH>          | Sets the location of the config file.               |
+| -t, --default_time_value <TIME>     | Default time value for graphs.                      |
+| --default_widget_count <INT>        | Sets the n'th selected widget type as the default.  |
+| --default_widget_type <WIDGET TYPE> | Sets the default widget type, use --help for info.  |
+| --disable_click                     | Disables mouse clicks.                              |
+| -m, --dot_marker                    | Uses a dot marker for graphs.                       |
+| -e, --expanded                      | Expand the default widget upon starting the app.    |
+| --hide_table_gap                    | Hides spacing between table headers and entries.    |
+| --hide_time                         | Hides the time scale.                               |
+| -l, --left_legend                   | Puts the CPU chart legend to the left side.         |
+| -r, --rate <TIME>                   | Sets the data refresh rate.                         |
+| --retention <TIME>                  | The timespan of data stored.                        |
+| --show_table_scroll_position        | Shows the scroll position tracker in table widgets. |
+| -d, --time_delta <TIME>             | The amount of time changed upon zooming.            |
+
+## Process Options
+
+| Option                  | Behaviour                                                             |
+| ----------------------- | --------------------------------------------------------------------- |
+| -S, --case_sensitive    | Enables case sensitivity by default.                                  |
+| -u, --current_usage     | Sets process CPU% to be based on current CPU%.                        |
+| --disable_advanced_kill | Hides advanced process killing.                                       |
+| -g, --group_processes   | Groups processes with the same name by default.                       |
+| --process_command       | Show processes as their commands by default.                          |
+| -R, --regex             | Enables regex by default.                                             |
+| -T, --tree              | Defaults the process widget be in tree mode.                          |
+| -n, --unnormalized_cpu  | Show process CPU% usage without normalizing over the number of cores. |
+| -W, --whole_word        | Enables whole-word matching by default.                               |
+
+## Temperature Options
+
+| Option           | Behaviour                               |
+| ---------------- | --------------------------------------- |
+| -c, --celsius    | Use Celsius as the temperature unit.    |
+| -f, --fahrenheit | Use Fahrenheit as the temperature unit. |
+| -k, --kelvin     | Use Kelvin as the temperature unit.     |
+
+## CPU Options
+
+| Option             | Behaviour                    |
+| ------------------ | ---------------------------- |
+| -a, --hide_avg_cpu | Hides the average CPU usage. |
+
+## Memory Options
+
+| Option                | Behaviour                                                 |
+| --------------------- | --------------------------------------------------------- |
+| --enable_cache_memory | Enable collecting and displaying cache and buffer memory. |
+| --mem_as_value        | Defaults to showing process memory usage by value.        |
+
+## Network Options
+
+| Option                      | Behaviour                                         |
+| --------------------------- | ------------------------------------------------- |
+| --network_use_binary_prefix | Displays the network widget with binary prefixes. |
+| --network_use_bytes         | Displays the network widget using bytes.          |
+| --network_use_log           | Displays the network widget with a log scale.     |
+| --use_old_network_legend    | DEPRECATED - uses a separate network legend.      |
+
+## Battery Options
+
+| Option    | Behaviour                 |
+| --------- | ------------------------- |
+| --battery | Shows the battery widget. |
+
+## GPU Options
+
+| Option       | Behaviour                                   |
+| ------------ | ------------------------------------------- |
+| --enable_gpu | Enable collecting and displaying GPU usage. |
+
+## Style Options
+
+| Option                 | Behaviour                                |
+| ---------------------- | ---------------------------------------- |
+| --color <COLOR SCHEME> | Use a color scheme, use --help for info. |
+
+## Other Options
+
+| Option        | Behaviour                                  |
+| ------------- | ------------------------------------------ |
+| -h, --help    | Prints help (see more info with '--help'). |
+| -V, --version | Prints version information.                |
diff --git a/docs/content/configuration/config-file/flags.md b/docs/content/configuration/config-file/flags.md
index ed9d0aef..c110af6d 100644
--- a/docs/content/configuration/config-file/flags.md
+++ b/docs/content/configuration/config-file/flags.md
@@ -4,7 +4,7 @@
 
     This section is in progress, and is just copied from the old documentation.
 
-Most of the [command line flags](../command-line-flags.md) have config file equivalents to avoid having to type them out
+Most of the [command line flags](../command-line-options.md) have config file equivalents to avoid having to type them out
 each time:
 
 | Field                        | Type                                                                                           | Functionality                                                                        |
diff --git a/docs/content/index.md b/docs/content/index.md
index 2977f67f..39969b9a 100644
--- a/docs/content/index.md
+++ b/docs/content/index.md
@@ -31,7 +31,7 @@ which contains a list of all the installation methods.
 
 You can refer to the [usage](usage/general-usage.md) pages on how to use bottom (e.g. keybinds, some features, a general overview of what each widget does).
 
-To configure bottom, refer to the [configuration](configuration/command-line-flags.md) pages (e.g. how it behaves, how it looks).
+To configure bottom, refer to the [configuration](configuration/command-line-options.md) pages (e.g. how it behaves, how it looks).
 
 ## Contribution
 
diff --git a/docs/content/usage/widgets/network.md b/docs/content/usage/widgets/network.md
index 96369f87..9cf1e9e2 100644
--- a/docs/content/usage/widgets/network.md
+++ b/docs/content/usage/widgets/network.md
@@ -12,7 +12,7 @@ received and transmitted.
 The legend displays the current reads and writes per second in bits, as well as the total amount read/written.
 
 The y-axis automatically scales based on shown read/write values, and by default, is a linear scale based on base-10 units (e.x. kilobit, gigabit, etc.).
-Through [configuration](../../configuration/command-line-flags.md), the read/write per second unit can be changed to bytes, while the y-axis can be changed to a
+Through [configuration](../../configuration/command-line-options.md), the read/write per second unit can be changed to bytes, while the y-axis can be changed to a
 log scale and/or use base-2 units (e.x. kibibit, gibibit, etc.).
 
 One can also adjust the displayed time range through either the keyboard or mouse, with a range of 30s to 600s.
diff --git a/docs/mkdocs.yml b/docs/mkdocs.yml
index 81a484c1..f76d26cb 100644
--- a/docs/mkdocs.yml
+++ b/docs/mkdocs.yml
@@ -140,7 +140,7 @@ nav:
           - "Temperature Widget": usage/widgets/temperature.md
           - "Battery Widget": usage/widgets/battery.md
   - "Configuration":
-      - "Command-line Flags": configuration/command-line-flags.md
+      - "Command-line Flags": configuration/command-line-options.md
       - "Config File":
           - "Default Config": configuration/config-file/default-config.md
           - "Flags": configuration/config-file/flags.md
diff --git a/src/options/args.rs b/src/options/args.rs
index 30fe88c9..a2182577 100644
--- a/src/options/args.rs
+++ b/src/options/args.rs
@@ -3,6 +3,8 @@
 //! Note that you probably want to keep this as a single file so the build script doesn't
 //! trip all over itself.
 
+use std::cmp::Ordering;
+
 use clap::{builder::PossibleValuesParser, *};
 
 const DEFAULT_WIDGET_TYPE_STR: &str = {
@@ -80,132 +82,119 @@ pub fn get_matches() -> ArgMatches {
     build_app().get_matches()
 }
 
-trait CommandBuilder {
-    fn general_args(self) -> Self;
-
-    fn style_args(self) -> Self;
-
-    fn temperature_args(self) -> Self;
-
-    fn process_args(self) -> Self;
-
-    fn cpu_args(self) -> Self;
-
-    fn mem_args(self) -> Self;
-
-    fn network_args(self) -> Self;
+/// Returns an [`Ordering`] for two [`Arg`] values.
+///
+/// Note this assumes that they both have a _long_ name, and will
+/// panic if either are missing!
+fn sort_args(a: &Arg, b: &Arg) -> Ordering {
+    let a = a.get_long().unwrap();
+    let b = b.get_long().unwrap();
 
-    fn battery_args(self) -> Self;
-
-    fn gpu_args(self) -> Self;
+    a.cmp(b)
+}
 
-    fn other(self) -> Self;
+/// Create an array of [`Arg`] values. If there is more than one value, then
+/// they will be sorted by their long name. Note this sort will panic if
+/// any [`Arg`] does not have a long name!
+macro_rules! args {
+    ( $arg:expr $(,)?) => {
+        [$arg]
+    };
+    ( $( $arg:expr ),+ $(,)? ) => {
+        {
+            let mut args = [ $( $arg, )* ];
+            args.sort_unstable_by(sort_args);
+            args
+        }
+    };
 }
 
-impl CommandBuilder for Command {
-    fn general_args(self) -> Command {
-        const HEADING: &str = "General Options";
+fn general_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("General Options");
 
-        let autohide_time = Arg::new("autohide_time")
-            .long("autohide_time")
-            .action(ArgAction::SetTrue)
-            .help("Temporarily shows the time scale in graphs.")
-            .long_help(
-                "Automatically hides the time scale in graphs after being shown for \
+    let autohide_time = Arg::new("autohide_time")
+        .long("autohide_time")
+        .action(ArgAction::SetTrue)
+        .help("Temporarily shows the time scale in graphs.")
+        .long_help(
+            "Automatically hides the time scale in graphs after being shown for \
             a brief moment when zoomed in/out. If time is disabled via --hide_time \
             then this will have no effect.",
-            )
-            .help_heading(HEADING);
-
-        let basic = Arg::new("basic")
-            .short('b')
-            .long("basic")
-            .action(ArgAction::SetTrue)
-            .help("Hides graphs and uses a more basic look.")
-            .long_help(
-                "Hides graphs and uses a more basic look. Design is largely inspired by htop's.",
-            )
-            .help_heading(HEADING);
-
-        let disable_click = Arg::new("disable_click")
-            .long("disable_click")
-            .action(ArgAction::SetTrue)
-            .help("Disables mouse clicks.")
-            .long_help("Disables mouse clicks from interacting with the program.")
-            .help_heading(HEADING);
-
-        let dot_marker = Arg::new("dot_marker")
-            .short('m')
-            .long("dot_marker")
-            .action(ArgAction::SetTrue)
-            .help("Uses a dot marker for graphs.")
-            .long_help("Uses a dot marker for graphs as opposed to the default braille marker.")
-            .help_heading(HEADING);
-
-        let hide_table_gap = Arg::new("hide_table_gap")
-            .long("hide_table_gap")
-            .action(ArgAction::SetTrue)
-            .help("Hides spacing between table headers and entries.")
-            .long_help("Hides the spacing between table headers and entries.")
-            .help_heading(HEADING);
-
-        let hide_time = Arg::new("hide_time")
-            .long("hide_time")
-            .action(ArgAction::SetTrue)
-            .help("Hides the time scale.")
-            .long_help("Completely hides the time scale from being shown.")
-            .help_heading(HEADING);
+        );
 
-        let left_legend = Arg::new("left_legend")
-            .short('l')
-            .long("left_legend")
-            .action(ArgAction::SetTrue)
-            .help("Puts the CPU chart legend to the left side.")
-            .long_help("Puts the CPU chart legend to the left side rather than the right side.")
-            .help_heading(HEADING);
+    let basic = Arg::new("basic")
+        .short('b')
+        .long("basic")
+        .action(ArgAction::SetTrue)
+        .help("Hides graphs and uses a more basic look.")
+        .long_help(
+            "Hides graphs and uses a more basic look. Design is largely inspired by htop's.",
+        );
 
-        let show_table_scroll_position = Arg::new("show_table_scroll_position")
-            .long("show_table_scroll_position")
-            .action(ArgAction::SetTrue)
-            .help("Shows the scroll position tracker in table widgets.")
-            .long_help(
-                "Shows the list scroll position tracker in the widget title for table widgets.",
-            )
-            .help_heading(HEADING);
-
-        let config_location = Arg::new("config_location")
-            .short('C')
-            .long("config")
-            .action(ArgAction::Set)
-            .value_name("CONFIG PATH")
-            .help("Sets the location of the config file.")
-            .long_help(
-                "Sets the location of the config file. Expects a config file in the TOML format. \
-                If it doesn't exist, one is created.",
-            )
-            .value_hint(ValueHint::AnyPath)
-            .help_heading(HEADING);
-
-        let default_time_value = Arg::new("default_time_value")
+    let disable_click = Arg::new("disable_click")
+        .long("disable_click")
+        .action(ArgAction::SetTrue)
+        .help("Disables mouse clicks.")
+        .long_help("Disables mouse clicks from interacting with the program.");
+
+    let dot_marker = Arg::new("dot_marker")
+        .short('m')
+        .long("dot_marker")
+        .action(ArgAction::SetTrue)
+        .help("Uses a dot marker for graphs.")
+        .long_help("Uses a dot marker for graphs as opposed to the default braille marker.");
+
+    let hide_table_gap = Arg::new("hide_table_gap")
+        .long("hide_table_gap")
+        .action(ArgAction::SetTrue)
+        .help("Hides spacing between table headers and entries.")
+        .long_help("Hides the spacing between table headers and entries.");
+
+    let hide_time = Arg::new("hide_time")
+        .long("hide_time")
+        .action(ArgAction::SetTrue)
+        .help("Hides the time scale.")
+        .long_help("Completely hides the time scale from being shown.");
+
+    let left_legend = Arg::new("left_legend")
+        .short('l')
+        .long("left_legend")
+        .action(ArgAction::SetTrue)
+        .help("Puts the CPU chart legend to the left side.")
+        .long_help("Puts the CPU chart legend to the left side rather than the right side.");
+
+    let show_table_scroll_position = Arg::new("show_table_scroll_position")
+        .long("show_table_scroll_position")
+        .action(ArgAction::SetTrue)
+        .help("Shows the scroll position tracker in table widgets.")
+        .long_help("Shows the list scroll position tracker in the widget title for table widgets.");
+
+    let config_location = Arg::new("config_location")
+        .short('C')
+        .long("config")
+        .action(ArgAction::Set)
+        .value_name("CONFIG PATH")
+        .help("Sets the location of the config file.")
+        .long_help("Sets the location of the config file. Expects a config file in the TOML format. If it doesn't exist, one is created.")
+        .value_hint(ValueHint::AnyPath);
+
+    let default_time_value = Arg::new("default_time_value")
             .short('t')
             .long("default_time_value")
             .action(ArgAction::Set)
             .value_name("TIME")
             .help("Default time value for graphs.")
-            .long_help(
-                "Default time value for graphs. Takes a number in milliseconds or a human duration (e.g. 60s). The minimum time is 30s, and the default is 60s.",
-            )
-            .help_heading(HEADING);
-
-        // TODO: Charts are broken in the manpage
-        let default_widget_count = Arg::new("default_widget_count")
-            .long("default_widget_count")
-            .action(ArgAction::Set)
-            .requires_all(["default_widget_type"])
-            .value_name("INT")
-            .help("Sets the n'th selected widget type as the default.")
-            .long_help(
-                "\
+            .long_help("Default time value for graphs. Takes a number in milliseconds or a human duration (e.g. 60s). The minimum time is 30s, and the default is 60s.");
+
+    // TODO: Charts are broken in the manpage
+    let default_widget_count = Arg::new("default_widget_count")
+        .long("default_widget_count")
+        .action(ArgAction::Set)
+        .requires_all(["default_widget_type"])
+        .value_name("INT")
+        .help("Sets the n'th selected widget type as the default.")
+        .long_help(
+            "\
 Sets the n'th selected widget type to use as the default widget.
 Requires 'default_widget_type' to also be set, and defaults to 1.
 
@@ -222,94 +211,85 @@ And we set our default widget type to 'CPU'. If we set
 the default widget. If we set '--default_widget_count 3', it would
 use CPU (3) as the default instead.
     ",
-            )
-            .help_heading(HEADING);
-
-        let default_widget_type = Arg::new("default_widget_type")
-            .long("default_widget_type")
-            .action(ArgAction::Set)
-            .value_name("WIDGET TYPE")
-            .help("Sets the default widget type, use --help for info.")
-            .long_help(DEFAULT_WIDGET_TYPE_STR)
-            .help_heading(HEADING);
-
-        let expanded_on_startup = Arg::new("expanded_on_startup")
-            .short('e')
-            .long("expanded")
-            .action(ArgAction::SetTrue)
-            .help("Expand the default widget upon starting the app.")
-            .long_help("Expand the default widget upon starting the app. Same as pressing \"e\" inside the app. Use with \"default_widget_type\" and \"default_widget_count\" to select desired expanded widget. This flag has no effect in basic mode (--basic)")
-            .help_heading(HEADING);
-
-        let rate = Arg::new("rate")
-            .short('r')
-            .long("rate")
-            .action(ArgAction::Set)
-            .value_name("TIME")
-            .help("Sets the data refresh rate.")
-            .long_help("Sets the data refresh rate. Takes a number in milliseconds or a human duration (e.g. 5s). The minimum is 250ms, and defaults to 1000ms. Smaller values may take more computer resources.")
-            .help_heading(HEADING);
-
-        let time_delta = Arg::new("time_delta")
-            .short('d')
-            .long("time_delta")
-            .action(ArgAction::Set)
-            .value_name("TIME")
-            .help("The amount of time changed upon zooming.")
-            .long_help("The amount of time changed when zooming in/out. Takes a number in milliseconds or a human duration (e.g. 30s). The minimum is 1s, and defaults to 15s.")
-            .help_heading(HEADING);
-
-        let retention = Arg::new("retention")
-            .long("retention")
-            .action(ArgAction::Set)
-            .value_name("TIME")
-            .help("The timespan of data stored.")
-            .long_help("How much data is stored at once in terms of time. Takes a number in milliseconds or a human duration (e.g. 20m), with a minimum of 1 minute. Note higher values will take up more memory. Defaults to 10 minutes.")
-            .help_heading(HEADING);
-
-        let mut args = [
-            autohide_time,
-            basic,
-            disable_click,
-            dot_marker,
-            hide_table_gap,
-            hide_time,
-            left_legend,
-            show_table_scroll_position,
-            config_location,
-            default_time_value,
-            default_widget_count,
-            default_widget_type,
-            expanded_on_startup,
-            rate,
-            time_delta,
-            retention,
-        ];
-        args.sort_unstable();
-
-        self.args(args)
-    }
+        );
 
-    fn style_args(self) -> Command {
-        const HEADING: &str = "Style Options";
+    let default_widget_type = Arg::new("default_widget_type")
+        .long("default_widget_type")
+        .action(ArgAction::Set)
+        .value_name("WIDGET TYPE")
+        .help("Sets the default widget type, use --help for info.")
+        .long_help(DEFAULT_WIDGET_TYPE_STR);
+
+    let expanded_on_startup = Arg::new("expanded_on_startup")
+        .short('e')
+        .long("expanded")
+        .action(ArgAction::SetTrue)
+        .help("Expand the default widget upon starting the app.")
+        .long_help("Expand the default widget upon starting the app. Same as pressing \"e\" inside the app. Use with \"default_widget_type\" and \"default_widget_count\" to select desired expanded widget. This flag has no effect in basic mode (--basic).");
+
+    let rate = Arg::new("rate")
+        .short('r')
+        .long("rate")
+        .action(ArgAction::Set)
+        .value_name("TIME")
+        .help("Sets the data refresh rate.")
+        .long_help("Sets the data refresh rate. Takes a number in milliseconds or a human duration (e.g. 5s). The minimum is 250ms, and defaults to 1000ms. Smaller values may take more computer resources.");
+
+    let time_delta = Arg::new("time_delta")
+        .short('d')
+        .long("time_delta")
+        .action(ArgAction::Set)
+        .value_name("TIME")
+        .help("The amount of time changed upon zooming.")
+        .long_help("The amount of time changed when zooming in/out. Takes a number in milliseconds or a human duration (e.g. 30s). The minimum is 1s, and defaults to 15s.");
+
+    let retention = Arg::new("retention")
+        .long("retention")
+        .action(ArgAction::Set)
+        .value_name("TIME")
+        .help("The timespan of data stored.")
+        .long_help("How much data is stored at once in terms of time. Takes a number in milliseconds or a human duration (e.g. 20m), with a minimum of 1 minute. Note higher values will take up more memory. Defaults to 10 minutes.");
+
+    cmd.args(args![
+        autohide_time,
+        basic,
+        disable_click,
+        dot_marker,
+        hide_table_gap,
+        hide_time,
+        left_legend,
+        show_table_scroll_position,
+        config_location,
+        default_time_value,
+        default_widget_count,
+        default_widget_type,
+        expanded_on_startup,
+        rate,
+        time_delta,
+        retention,
+    ])
+}
 
-        // TODO: File an issue with manpage, it cannot render charts correctly.
-        let color = Arg::new("color")
-            .long("color")
-            .action(ArgAction::Set)
-            .value_name("COLOR SCHEME")
-            .value_parser(PossibleValuesParser::new([
-                "default",
-                "default-light",
-                "gruvbox",
-                "gruvbox-light",
-                "nord",
-                "nord-light",
-            ]))
-            .hide_possible_values(true)
-            .help("Use a color scheme, use --help for info.")
-            .long_help(
-                "\
+fn style_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("Style Options");
+
+    // TODO: File an issue with manpage, it cannot render charts correctly.
+    let color = Arg::new("color")
+        .long("color")
+        .action(ArgAction::Set)
+        .value_name("COLOR SCHEME")
+        .value_parser(PossibleValuesParser::new([
+            "default",
+            "default-light",
+            "gruvbox",
+            "gruvbox-light",
+            "nord",
+            "nord-light",
+        ]))
+        .hide_possible_values(true)
+        .help("Use a color scheme, use --help for info.")
+        .long_help(
+            "\
 Use a pre-defined color scheme. Currently supported values are:
 +------------------------------------------------------------+
 | default                                                    |
@@ -326,285 +306,241 @@ Use a pre-defined color scheme. Currently supported values are:
 +------------------------------------------------------------+
 Defaults to \"default\".
     ",
-            )
-            .help_heading(HEADING);
-
-        self.arg(color)
-    }
-
-    fn temperature_args(self) -> Command {
-        const HEADING: &str = "Temperature Options";
-
-        let celsius = Arg::new("celsius")
-            .short('c')
-            .long("celsius")
-            .action(ArgAction::SetTrue)
-            .help("Use Celsius as the temperature unit.")
-            .long_help("Use Celsius as the temperature unit. This is the default option.")
-            .help_heading(HEADING);
-
-        let fahrenheit = Arg::new("fahrenheit")
-            .short('f')
-            .long("fahrenheit")
-            .action(ArgAction::SetTrue)
-            .help("Use Fahrenheit as the temperature unit.")
-            .help_heading(HEADING);
-
-        let kelvin = Arg::new("kelvin")
-            .short('k')
-            .long("kelvin")
-            .action(ArgAction::SetTrue)
-            .help("Use Kelvin as the temperature unit.")
-            .help_heading(HEADING);
-
-        let temperature_group = ArgGroup::new("TEMPERATURE_TYPE").args([
-            celsius.get_id(),
-            fahrenheit.get_id(),
-            kelvin.get_id(),
-        ]);
-
-        let args = [celsius, fahrenheit, kelvin];
+        );
 
-        self.args(args).group(temperature_group)
-    }
+    cmd.arg(color)
+}
 
-    fn process_args(self) -> Command {
-        const HEADING: &str = "Process Options";
+fn temperature_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("Temperature Options");
+
+    let celsius = Arg::new("celsius")
+        .short('c')
+        .long("celsius")
+        .action(ArgAction::SetTrue)
+        .help("Use Celsius as the temperature unit.")
+        .long_help("Use Celsius as the temperature unit. This is the default option.");
+
+    let fahrenheit = Arg::new("fahrenheit")
+        .short('f')
+        .long("fahrenheit")
+        .action(ArgAction::SetTrue)
+        .help("Use Fahrenheit as the temperature unit.");
+
+    let kelvin = Arg::new("kelvin")
+        .short('k')
+        .long("kelvin")
+        .action(ArgAction::SetTrue)
+        .help("Use Kelvin as the temperature unit.");
+
+    let temperature_group = ArgGroup::new("TEMPERATURE_TYPE").args([
+        celsius.get_id(),
+        fahrenheit.get_id(),
+        kelvin.get_id(),
+    ]);
+
+    cmd.args(args![celsius, fahrenheit, kelvin])
+        .group(temperature_group)
+}
 
-        let case_sensitive = Arg::new("case_sensitive")
-            .short('S')
-            .long("case_sensitive")
-            .action(ArgAction::SetTrue)
-            .help("Enables case sensitivity by default.")
-            .long_help("When searching for a process, enables case sensitivity by default.")
-            .help_heading(HEADING);
+fn process_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("Process Options");
+
+    let case_sensitive = Arg::new("case_sensitive")
+        .short('S')
+        .long("case_sensitive")
+        .action(ArgAction::SetTrue)
+        .help("Enables case sensitivity by default.")
+        .long_help("When searching for a process, enables case sensitivity by default.");
+
+    let current_usage = Arg::new("current_usage")
+        .short('u')
+        .long("current_usage")
+        .action(ArgAction::SetTrue)
+        .help("Sets process CPU% to be based on current CPU%.")
+        .long_help("Sets process CPU% usage to be based on the current system CPU% usage rather than total CPU usage.");
+
+    let unnormalized_cpu = Arg::new("unnormalized_cpu")
+        .short('n')
+        .long("unnormalized_cpu")
+        .action(ArgAction::SetTrue)
+        .help("Show process CPU% usage without normalizing over the number of cores.")
+        .long_help("Shows all process CPU% usage without averaging over the number of CPU cores in the system.");
+
+    let group_processes = Arg::new("group_processes")
+        .short('g')
+        .long("group_processes")
+        .action(ArgAction::SetTrue)
+        .help("Groups processes with the same name by default.")
+        .long_help("Groups processes with the same name by default.");
+
+    let process_command = Arg::new("process_command")
+        .long("process_command")
+        .action(ArgAction::SetTrue)
+        .help("Show processes as their commands by default.")
+        .long_help("Show processes as their commands by default in the process widget.");
+
+    let regex = Arg::new("regex")
+        .short('R')
+        .long("regex")
+        .action(ArgAction::SetTrue)
+        .help("Enables regex by default.")
+        .long_help("When searching for a process, enables regex by default.");
+
+    let disable_advanced_kill = Arg::new("disable_advanced_kill")
+        .long("disable_advanced_kill")
+        .action(ArgAction::SetTrue)
+        .help("Hides advanced process killing.")
+        .long_help("Hides advanced options to stop a process on Unix-like systems. The only option shown is 15 (TERM).");
+
+    let whole_word = Arg::new("whole_word")
+        .short('W')
+        .long("whole_word")
+        .action(ArgAction::SetTrue)
+        .help("Enables whole-word matching by default.")
+        .long_help(
+            "When searching for a process, return results that match the entire query by default.",
+        );
 
-        let current_usage = Arg::new("current_usage")
-            .short('u')
-            .long("current_usage")
-            .action(ArgAction::SetTrue)
-            .help("Sets process CPU% to be based on current CPU%.")
-            .long_help("Sets process CPU% usage to be based on the current system CPU% usage rather than total CPU usage.")
-            .help_heading(HEADING);
+    let tree = Arg::new("tree")
+        .short('T')
+        .long("tree")
+        .action(ArgAction::SetTrue)
+        .help("Defaults the process widget be in tree mode.")
+        .long_help("Defaults to showing the process widget in tree mode.");
+
+    let args = args![
+        case_sensitive,
+        current_usage,
+        unnormalized_cpu,
+        group_processes,
+        process_command,
+        regex,
+        whole_word,
+        disable_advanced_kill,
+        tree,
+    ];
+
+    cmd.args(args)
+}
 
-        let unnormalized_cpu = Arg::new("unnormalized_cpu")
-            .short('n')
-            .long("unnormalized_cpu")
-            .action(ArgAction::SetTrue)
-            .help("Show process CPU% usage without normalizing over the number of cores.")
-            .long_help(
-                "Shows all process CPU% usage without averaging over the number of CPU cores in the system.",
-            )
-            .help_heading(HEADING);
-
-        let group_processes = Arg::new("group_processes")
-            .short('g')
-            .long("group_processes")
-            .action(ArgAction::SetTrue)
-            .help("Groups processes with the same name by default.")
-            .long_help("Groups processes with the same name by default.")
-            .help_heading(HEADING);
+fn cpu_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("CPU Options");
 
-        let process_command = Arg::new("process_command")
-            .long("process_command")
-            .action(ArgAction::SetTrue)
-            .help("Show processes as their commands by default.")
-            .long_help("Show processes as their commands by default in the process widget.")
-            .help_heading(HEADING);
+    let hide_avg_cpu = Arg::new("hide_avg_cpu")
+        .short('a')
+        .long("hide_avg_cpu")
+        .action(ArgAction::SetTrue)
+        .help("Hides the average CPU usage.")
+        .long_help("Hides the average CPU usage from being shown.");
 
-        let regex = Arg::new("regex")
-            .short('R')
-            .long("regex")
-            .action(ArgAction::SetTrue)
-            .help("Enables regex by default.")
-            .long_help("When searching for a process, enables regex by default.")
-            .help_heading(HEADING);
+    // let default_avg_cpu = Arg::new("");
 
-        let disable_advanced_kill = Arg::new("disable_advanced_kill")
-            .long("disable_advanced_kill")
-            .action(ArgAction::SetTrue)
-            .help("Hides advanced process killing.")
-            .long_help("Hides advanced options to stop a process on Unix-like systems. The only option shown is 15 (TERM).")
-            .help_heading(HEADING);
+    cmd.args(args![hide_avg_cpu])
+}
 
-        let whole_word = Arg::new("whole_word")
-            .short('W')
-            .long("whole_word")
-            .action(ArgAction::SetTrue)
-            .help("Enables whole-word matching by default.")
-            .long_help(
-                "When searching for a process, return results that match the entire query by default.",
-            )
-            .help_heading(HEADING);
-
-        let tree = Arg::new("tree")
-            .short('T')
-            .long("tree")
-            .action(ArgAction::SetTrue)
-            .help("Defaults the process widget be in tree mode.")
-            .long_help("Defaults to showing the process widget in tree mode.")
-            .help_heading(HEADING);
-
-        let mut args = [
-            case_sensitive,
-            current_usage,
-            unnormalized_cpu,
-            group_processes,
-            process_command,
-            regex,
-            whole_word,
-            disable_advanced_kill,
-            tree,
-        ];
-        args.sort_unstable();
-
-        self.args(args)
-    }
+fn mem_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("Memory Options");
 
-    fn cpu_args(self) -> Command {
-        const HEADING: &str = "CPU Options";
+    let mem_as_value = Arg::new("mem_as_value")
+        .long("mem_as_value")
+        .action(ArgAction::SetTrue)
+        .help("Defaults to showing process memory usage by value.")
+        .long_help("Defaults to showing process memory usage by value. Otherwise, it defaults to showing it by percentage.");
 
-        let hide_avg_cpu = Arg::new("hide_avg_cpu")
-            .short('a')
-            .long("hide_avg_cpu")
+    #[cfg(not(target_os = "windows"))]
+    {
+        let enable_cache_memory = Arg::new("enable_cache_memory")
+            .long("enable_cache_memory")
             .action(ArgAction::SetTrue)
-            .help("Hides the average CPU usage.")
-            .long_help("Hides the average CPU usage from being shown.")
-            .help_heading(HEADING);
+            .help("Enable collecting and displaying cache and buffer memory.");
 
-        self.arg(hide_avg_cpu)
+        cmd.args(args![mem_as_value, enable_cache_memory])
     }
-
-    fn mem_args(self) -> Command {
-        const HEADING: &str = "Memory Options";
-
-        let mem_as_value = Arg::new("mem_as_value")
-            .long("mem_as_value")
-            .action(ArgAction::SetTrue)
-            .help("Defaults to showing process memory usage by value.")
-            .long_help("Defaults to showing process memory usage by value. Otherwise, it defaults to showing it by percentage.")
-            .help_heading(HEADING);
-
-        #[cfg(not(target_os = "windows"))]
-        {
-            let enable_cache_memory = Arg::new("enable_cache_memory")
-                .long("enable_cache_memory")
-                .action(ArgAction::SetTrue)
-                .help("Enable collecting and displaying cache and buffer memory.")
-                .help_heading(HEADING);
-
-            self.args([mem_as_value, enable_cache_memory])
-        }
-        #[cfg(target_os = "windows")]
-        {
-            self.arg(mem_as_value)
-        }
+    #[cfg(target_os = "windows")]
+    {
+        cmd.arg(mem_as_value)
     }
+}
 
-    fn network_args(self) -> Command {
-        const HEADING: &str = "Network Options";
+fn network_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("Network Options");
+
+    let use_old_network_legend = Arg::new("use_old_network_legend")
+        .long("use_old_network_legend")
+        .action(ArgAction::SetTrue)
+        .help("DEPRECATED - uses a separate network legend.")
+        .long_help("DEPRECATED - uses an older (pre-0.4), separate network widget legend. This display is not tested anymore and may be broken.");
+
+    let network_use_bytes = Arg::new("network_use_bytes")
+        .long("network_use_bytes")
+        .action(ArgAction::SetTrue)
+        .help("Displays the network widget using bytes.")
+        .long_help("Displays the network widget using bytes. Defaults to bits.");
+
+    let network_use_log = Arg::new("network_use_log")
+        .long("network_use_log")
+        .action(ArgAction::SetTrue)
+        .help("Displays the network widget with a log scale.")
+        .long_help("Displays the network widget with a log scale. Defaults to a non-log scale.");
+
+    let network_use_binary_prefix = Arg::new("network_use_binary_prefix")
+        .long("network_use_binary_prefix")
+        .action(ArgAction::SetTrue)
+        .help("Displays the network widget with binary prefixes.")
+        .long_help("Displays the network widget with binary prefixes (i.e. kibibits, mebibits) rather than a decimal prefix (i.e. kilobits, megabits). Defaults to decimal prefixes.");
+
+    cmd.args(args![
+        use_old_network_legend,
+        network_use_bytes,
+        network_use_log,
+        network_use_binary_prefix,
+    ])
+}
 
-        let use_old_network_legend = Arg::new("use_old_network_legend")
-            .long("use_old_network_legend")
-            .action(ArgAction::SetTrue)
-            .help("DEPRECATED - uses a separate network legend.")
-            .long_help(
-                "DEPRECATED - uses an older (pre-0.4), separate network widget legend. This display is not \
-                tested anymore and could be broken.",
-            )
-            .help_heading(HEADING);
-
-        let network_use_bytes = Arg::new("network_use_bytes")
-            .long("network_use_bytes")
-            .action(ArgAction::SetTrue)
-            .help("Displays the network widget using bytes.")
-            .long_help("Displays the network widget using bytes. Defaults to bits.")
-            .help_heading(HEADING);
+#[cfg(feature = "battery")]
+fn battery_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("Battery Options");
 
-        let network_use_log = Arg::new("network_use_log")
-            .long("network_use_log")
-            .action(ArgAction::SetTrue)
-            .help("Displays the network widget with a log scale.")
-            .long_help("Displays the network widget with a log scale. Defaults to a non-log scale.")
-            .help_heading(HEADING);
+    let battery = Arg::new("battery")
+        .long("battery")
+        .action(ArgAction::SetTrue)
+        .help("Shows the battery widget.")
+        .long_help(
+            "Shows the battery widget in default or basic mode. No effect on custom layouts.",
+        );
 
-        let network_use_binary_prefix = Arg::new("network_use_binary_prefix")
-            .long("network_use_binary_prefix")
-            .action(ArgAction::SetTrue)
-            .help("Displays the network widget with binary prefixes.")
-            .long_help(
-                "Displays the network widget with binary prefixes (i.e. kibibits, mebibits) rather than a decimal prefix (i.e. kilobits, megabits). Defaults to decimal prefixes.",
-            )
-            .help_heading(HEADING);
-
-        let mut args = [
-            use_old_network_legend,
-            network_use_bytes,
-            network_use_log,
-            network_use_binary_prefix,
-        ];
-
-        args.sort_unstable();
-
-        self.args(args)
-    }
+    cmd.arg(battery)
+}
 
-    fn battery_args(self) -> Command {
-        #[cfg(feature = "battery")]
-        {
-            let battery = Arg::new("battery")
-            .long("battery")
-            .action(ArgAction::SetTrue)
-            .help("Shows the battery widget.")
-            .long_help(
-                "Shows the battery widget in default or basic mode. No effect on custom layouts.",
-            )
-            .help_heading("Battery Options");
+#[cfg(feature = "gpu")]
+fn gpu_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("GPU Options");
 
-            self.arg(battery)
-        }
-        #[cfg(not(feature = "battery"))]
-        {
-            self
-        }
-    }
+    let enable_gpu = Arg::new("enable_gpu")
+        .long("enable_gpu")
+        .action(ArgAction::SetTrue)
+        .help("Enable collecting and displaying GPU usage.");
 
-    fn gpu_args(self) -> Command {
-        #[cfg(feature = "gpu")]
-        {
-            let enable_gpu = Arg::new("enable_gpu")
-                .long("enable_gpu")
-                .action(ArgAction::SetTrue)
-                .help("Enable collecting and displaying GPU usage.")
-                .help_heading("GPU Options");
-
-            self.arg(enable_gpu)
-        }
-        #[cfg(not(feature = "gpu"))]
-        {
-            self
-        }
-    }
+    cmd.arg(enable_gpu)
+}
 
-    fn other(self) -> Command {
-        const HEADING: &str = "Other Options";
+fn other_args(cmd: Command) -> Command {
+    let cmd = cmd.next_help_heading("Other Options");
 
-        let version = Arg::new("version")
-            .short('V')
-            .long("version")
-            .action(ArgAction::Version)
-            .help("Prints version information.")
-            .help_heading(HEADING);
+    let help = Arg::new("help")
+        .short('h')
+        .long("help")
+        .action(ArgAction::Help)
+        .help("Prints help (see more info with '--help').");
 
-        let help = Arg::new("help")
-            .short('h')
-            .long("help")
-            .action(ArgAction::Help)
-            .help("Prints help (see more with '--help').")
-            .help_heading(HEADING);
+    let version = Arg::new("version")
+        .short('V')
+        .long("version")
+        .action(ArgAction::Version)
+        .help("Prints version information.");
 
-        self.args([version, help])
-    }
+    cmd.args([help, version])
 }
 
 pub fn build_app() -> Command {
@@ -615,7 +551,7 @@ pub fn build_app() -> Command {
         None => crate_version!(),
     };
 
-    Command::new(crate_name!())
+    let cmd = Command::new(crate_name!())
         .author(crate_authors!())
         .about(crate_description!())
         .disable_help_flag(true)
@@ -623,17 +559,24 @@ pub fn build_app() -> Command {
         .color(ColorChoice::Auto)
         .help_template(TEMPLATE)
         .override_usage(USAGE)
-        .version(VERSION)
-        .general_args()
-        .style_args()
-        .temperature_args()
-        .process_args()
-        .cpu_args()
-        .mem_args()
-        .network_args()
-        .battery_args()
-        .gpu_args()
-        .other()
+        .version(VERSION);
+
+    [
+        general_args,
+        process_args,
+        temperature_args,
+        cpu_args,
+        mem_args,
+        network_args,
+        #[cfg(feature = "battery")]
+        battery_args,
+        #[cfg(feature = "gpu")]
+        gpu_args,
+        style_args,
+        other_args,
+    ]
+    .into_iter()
+    .fold(cmd, |c, f| f(c))
 }
 
 #[cfg(test)]
@@ -646,7 +589,7 @@ mod test {
     }
 
     #[test]
-    fn help_heading_no_default() {
+    fn no_default_help_heading() {
         let mut app = build_app();
         let help_str = app.render_help();
 
-- 
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