Move date to its own module

1 files changed, 112 insertions, 0 deletions

diff --git a/src/date.rs b/src/date.rs
new file mode 100644
index 0000000..185a817
--- /dev/null
+++ b/src/date.rs
@@ -0,0 +1,112 @@
+use std::cmp::{Ordering, Ord, PartialEq, PartialOrd};
+use std::str::FromStr;
+
+use errors::EventError;
+
+use chrono;
+use chrono::TimeZone;
+use chrono_tz::{Tz, UTC};
+
+
+#[derive(Debug, Copy, Clone, Eq)]
+pub enum Date {
+    Time(chrono::DateTime<Tz>),
+    AllDay(chrono::Date<Tz>),
+}
+
+
+impl Date {
+    pub fn empty() -> Date {
+        Date::Time(UTC.timestamp(0, 0))
+    }
+
+    pub fn parse(date: &String, time_zone: &String) -> Result<Self, EventError> {
+        let absolute_time = date.chars().rev().next().unwrap() == 'Z';
+        let tz: Tz = if absolute_time {
+            UTC
+        } else {
+            // FIXME: this should not be UTC but local timezone
+            time_zone.parse().unwrap_or(UTC)
+        };
+
+        let date = match date.find("T") {
+            Some(_) => {
+                let date_pattern = if absolute_time {
+                    "%Y%m%dT%H%M%SZ"
+                } else {
+                    "%Y%m%dT%H%M%S"
+                };
+                let time = tz.datetime_from_str(&date, date_pattern).unwrap_or(
+                    UTC.timestamp(0, 0),
+                );
+                Date::Time(time)
+            }
+            None => {
+                Date::AllDay(tz.ymd(
+                    i32::from_str(&date[0..4])?,
+                    u32::from_str(&date[4..6])?,
+                    u32::from_str(&date[6..8])?,
+                ))
+            }
+        };
+        Ok(date)
+    }
+}
+
+impl Ord for Date {
+    fn cmp(&self, other: &Self) -> Ordering {
+        match *self {
+            Date::Time(t1) => {
+                match *other {
+                    Date::Time(t2) => t1.cmp(&t2),
+                    Date::AllDay(d) => cmp_date_time(&d, &t1).reverse(),
+                }
+            }
+            Date::AllDay(d1) => {
+                match *other {
+                    Date::Time(t) => cmp_date_time(&d1, &t),
+                    Date::AllDay(d2) => d1.cmp(&d2),
+                }
+            }
+        }
+    }
+}
+
+impl PartialOrd for Date {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl PartialEq for Date {
+    fn eq(&self, other: &Self) -> bool {
+        self.cmp(other) == Ordering::Equal
+    }
+}
+
+fn cmp_date_time<T: TimeZone>(date: &chrono::Date<T>, time: &chrono::DateTime<T>) -> Ordering {
+    let d2 = time.date();
+    if date.eq(&d2) {
+        return Ordering::Less;
+    }
+    date.cmp(&d2)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Date;
+    use chrono::Datelike;
+    use chrono::Timelike;
+
+    #[test]
+    fn date_parse_time() {
+        match Date::parse(&String::from("19361020T120000"), &String::new()).unwrap() {
+            Date::Time(time) => {
+                assert_eq!(time.year(), 1936);
+                assert_eq!(time.hour(), 12);
+                assert_eq!(time.day(), 20);
+            }
+            _ => assert!(true),
+        }
+    }
+}