Add a CLI app that does the same as the GTK app

Cargo.toml

@@ -5,10 +5,13 @@ edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[features]
+gui = ["gtk", "adw", "gio"]
+
 [dependencies]
-adw = { version = "0.4", package = "libadwaita", features = ["v1_2"] }
-gio = "0.18.3"
-gtk = { version = "0.6", package = "gtk4" }
+adw = { version = "0.4", package = "libadwaita", features = ["v1_2"], optional = true }
+gio = { version = "0.18.3", optional = true }
+gtk = { version = "0.6", package = "gtk4", optional = true }
 icu = { version = "1.4.0", features = ["experimental"] }
 icu_provider = "1.4.0"
 icu_locid = "1.4.0"

src/bin/cli-app.rs

@@ -0,0 +1,96 @@
+use chrono::{Datelike, Local, Timelike};
+use icu::{
+    calendar::{
+        types::{IsoHour, IsoMinute, IsoSecond, NanoSecond, Time},
+        Date, DateTime,
+    },
+    datetime::{
+        options::length::{self, Bag},
+        DateTimeFormatter,
+    },
+};
+use icu_locid::Locale;
+use icu_provider::DataLocale;
+use libc::{self, LC_MESSAGES, LC_TIME};
+
+fn main() {
+    let now = chrono::Utc::now();
+    let now: icu::calendar::DateTime<icu::calendar::Gregorian> = icu::calendar::DateTime::new(
+        Date::try_new_gregorian_date(now.year() as i32, now.month() as u8, now.day() as u8)
+            .unwrap(),
+        Time::new(
+            IsoHour::try_from(now.hour() as u8).unwrap(),
+            IsoMinute::try_from(now.minute() as u8).unwrap(),
+            IsoSecond::try_from(now.second() as u8).unwrap(),
+            NanoSecond::try_from(0 as u32).unwrap(),
+        ),
+    );
+
+    let locales = ["en-US", "eo", "de-DE", "fr-FR", "es-ES", "zh-CN", "ja-JA"];
+    let styles: Vec<(String, Locale, Bag)> = locales
+        .into_iter()
+        .map(|locale| {
+            let lc = locale.parse::<Locale>().unwrap();
+            vec![
+                (
+                    format!("{}, full date", locale),
+                    lc.clone(),
+                    length::Bag::from_date_style(length::Date::Full).into(),
+                ),
+                (
+                    format!("{}, long date", locale),
+                    lc.clone(),
+                    length::Bag::from_date_style(length::Date::Long).into(),
+                ),
+                (
+                    format!("{}, medium date", locale),
+                    lc.clone(),
+                    length::Bag::from_date_style(length::Date::Medium).into(),
+                ),
+                (
+                    format!("{}, short date", locale),
+                    lc.clone(),
+                    length::Bag::from_date_style(length::Date::Short).into(),
+                ),
+                (
+                    format!("{}, full time", locale),
+                    lc.clone(),
+                    length::Bag::from_time_style(length::Time::Full).into(),
+                ),
+                (
+                    format!("{}, long time", locale),
+                    lc.clone(),
+                    length::Bag::from_time_style(length::Time::Long).into(),
+                ),
+                (
+                    format!("{}, medium time", locale),
+                    lc.clone(),
+                    length::Bag::from_time_style(length::Time::Medium).into(),
+                ),
+                (
+                    format!("{}, short time", locale),
+                    lc.clone(),
+                    length::Bag::from_time_style(length::Time::Short).into(),
+                ),
+            ]
+        })
+        .flatten()
+        .collect();
+
+    for (descriptor, locale, bag) in styles {
+        let formatter = DateTimeFormatter::try_new(&DataLocale::from(locale), bag.into());
+
+        match formatter {
+            Ok(formatter) => println!(
+                "[{:20}] {}",
+                descriptor,
+                &formatter.format_to_string(&now.to_any()).unwrap()
+            ),
+            Err(formatter_err) => println!(
+                "[{:20}] {}",
+                &descriptor,
+                &format!("unhandled formatter: {:?}", formatter_err),
+            ),
+        }
+    }
+}