Render times in local and UTC

l10n/src/lib.rs

@@ -1,28 +1,39 @@
 use std::ops::Deref;
 
-use chrono::{Datelike, FixedOffset, NaiveDate, Timelike};
+use chrono::{Datelike, FixedOffset, NaiveDate, TimeZone, Timelike};
-use chrono_tz::Tz;
+use chrono_tz::{OffsetName, Tz};
-use icu::datetime::options::length;
+use icu::{
-use icu_locid::locale;
+    datetime::options::length,
+    timezone::{CustomTimeZone, GmtOffset},
+};
+use icu_locid::{locale, Locale};
 use icu_provider::DataLocale;
-use sys_locale::get_locales;
+use std::str::FromStr;
+use sys_locale::get_locale;
 
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Debug)]
-pub struct L10N {}
+pub struct L10N {
+    locale: Locale,
+    zone: chrono_tz::Tz,
+}
 
 impl Default for L10N {
     fn default() -> Self {
-        Self {}
+        let lc = get_locale().unwrap();
+        let locale = Locale::try_from_bytes(lc.as_bytes()).unwrap();
+        let zone = chrono_tz::UTC;
+        Self { locale, zone }
     }
 }
 
 impl L10N {
     fn set_locale(&mut self, locale: String) {
-        unimplemented!()
+        let locale = Locale::try_from_bytes(locale.as_bytes()).unwrap();
+        self.locale = locale;
     }
 
     fn set_timezone(&mut self, zone: Tz) {
-        unimplemented!()
+        self.zone = zone;
     }
 
     // Need to take a message and turn it into a string in the current language. Except I don't
@@ -39,7 +50,15 @@ impl L10N {
         date_style: length::Date,
         time_style: length::Time,
     ) -> String {
-        unimplemented!()
+        let time: DateTime = time.with_timezone(&chrono_tz::UTC).into();
+        let options = length::Bag::from_date_time_style(date_style, time_style);
+        let formatter = icu::datetime::DateTimeFormatter::try_new(
+            &DataLocale::from(&self.locale),
+            options.into(),
+        )
+        .unwrap();
+        let icu_time: icu::calendar::DateTime<icu::calendar::Gregorian> = time.into();
+        formatter.format_to_string(&icu_time.to_any()).unwrap()
     }
 
     fn format_date_time_local(
@@ -48,9 +67,23 @@ impl L10N {
         date_style: length::Date,
         time_style: length::Time,
     ) -> String {
-        unimplemented!()
+        let time: DateTime = time.with_timezone(&self.zone).into();
+        let options = length::Bag::from_date_time_style(date_style, time_style);
+        let formatter = icu::datetime::DateTimeFormatter::try_new(
+            &DataLocale::from(&self.locale),
+            options.into(),
+        )
+        .unwrap();
+        let icu_time: icu::calendar::DateTime<icu::calendar::Gregorian> = time.into();
+        formatter.format_to_string(&icu_time.to_any()).unwrap()
     }
 
+    /*
+     * I have been unable to get from a chrono_tz::Tz to an ICU timezone. I have tried a variety of
+     * parsers on the CustomTimeZone object. I have not researched the data provider to see what is
+     * available there. The ZoneID for the reference date is US/Mountain, and the abbreviation is
+     * MST. I'll want to get to a CustomTimeZone so that the formatter can render MST or Mountain
+     * Standard Time or something similar.
         fn format_date_time_tz(
             &self,
             time: DateTime,
@@ -58,16 +91,35 @@ impl L10N {
             time_style: length::Time,
         ) -> String {
             let options = length::Bag::from_date_time_style(date_style, time_style);
-        let formatter = icu::datetime::DateTimeFormatter::try_new(
+            let formatter = icu::datetime::ZonedDateTimeFormatter::try_new(
-            &DataLocale::from(locale!("en-US")),
+                &DataLocale::from(&self.locale),
                 options.into(),
+                Default::default(),
             )
             .unwrap();
             let icu_time: icu::calendar::DateTime<icu::calendar::Gregorian> = time.into();
             let any = icu_time.to_any();
 
-        formatter.format_to_string(&any).unwrap()
+            println!("{:?}", time.offset());
+
+            let zone_id: String = time.offset().abbreviation().to_owned();
+            println!("{:?}", zone_id);
+            let zone_id = icu::timezone::TimeZoneBcp47Id::from_str(&zone_id).unwrap();
+
+            let zone: CustomTimeZone = CustomTimeZone {
+                gmt_offset: None,
+                time_zone_id: Some(zone_id),
+                /*
+                icu::timezone::TimeZoneBcp47Id::from_str(time.offset().tz_id().parse().unwrap())
+                    .unwrap(),
+                    */
+                metazone_id: None,
+                zone_variant: None,
+            };
+
+            formatter.format_to_string(&any, &zone).unwrap()
         }
+    */
 
     fn format_date(
         &self,
@@ -83,6 +135,7 @@ impl L10N {
     }
 }
 
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
 struct DateTime(chrono::DateTime<Tz>);
 
 impl Deref for DateTime {
@@ -119,23 +172,59 @@ impl From<DateTime> for icu::calendar::DateTime<icu::calendar::Gregorian> {
 mod tests {
     use super::*;
 
-    #[test]
+    fn reftime() -> DateTime {
-    fn it_formats_a_time_according_to_locale() {
+        NaiveDate::from_ymd_opt(2006, 1, 2)
-        let l10n = L10N::default();
-
-        let now = NaiveDate::from_ymd_opt(2006, 1, 2)
             .unwrap()
             .and_hms_opt(3, 4, 5)
             .unwrap()
-            .and_local_timezone(Tz::UTC)
+            .and_local_timezone(Tz::US__Mountain)
             .unwrap()
-            .into();
+            .into()
+    }
+
+    #[test]
+    fn it_formats_a_time_in_utc() {
+        let mut l10n = L10N::default();
+        // Make sure we know the locale before the test begins. Some systems, such as my own, are
+        // not actually in English.
+        l10n.set_locale("en-US".to_owned());
+        l10n.set_timezone(chrono_tz::US::Eastern);
+        let now = reftime();
 
         // 202f is the code-point for a narrow non-breaking space. Presumably this is used in
         // particular to ensure that the am/pm marker doesn't get split off from the time
         assert_eq!(
-            l10n.format_date_time_tz(now, length::Date::Long, length::Time::Medium),
+            l10n.format_date_time_utc(now.clone(), length::Date::Long, length::Time::Medium),
-            "January 2, 2006, 3:04:05\u{202f}AM"
+            "January 2, 2006, 10:04:05\u{202f}AM"
+        );
+
+        l10n.set_locale("eo-EO".to_owned());
+        assert_eq!(
+            l10n.format_date_time_utc(now.clone(), length::Date::Long, length::Time::Medium),
+            "2006-Januaro-02 10:04:05"
+        );
+    }
+
+    #[test]
+    fn it_formats_a_time_in_the_current_zone() {
+        let mut l10n = L10N::default();
+        // Make sure we know the locale before the test begins. Some systems, such as my own, are
+        // not actually in English.
+        l10n.set_locale("en-US".to_owned());
+        l10n.set_timezone(chrono_tz::US::Eastern);
+        let now = reftime();
+
+        // 202f is the code-point for a narrow non-breaking space. Presumably this is used in
+        // particular to ensure that the am/pm marker doesn't get split off from the time
+        assert_eq!(
+            l10n.format_date_time_local(now.clone(), length::Date::Long, length::Time::Medium),
+            "January 2, 2006, 5:04:05\u{202f}AM"
+        );
+
+        l10n.set_locale("eo-EO".to_owned());
+        assert_eq!(
+            l10n.format_date_time_local(now.clone(), length::Date::Long, length::Time::Medium),
+            "2006-Januaro-02 05:04:05"
         );
     }