Add end-of-month type/calc

Adds util module

4 files changed, 116 insertions, 14 deletions

diff --git a/src/error.rs b/src/error.rs
index 00fad98..4d4a0af 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -38,6 +38,11 @@ error_chain! {
             display("Argument Error: Cannot calculate end-of-year on a {:?}", tt)
         }
 
+        CannotCalculateEndOfMonthOn(tt: TimeType) {
+            description("Argument Error: Cannot calculate end-of-month")
+            display("Argument Error: Cannot calculate end-of-month on a {:?}", tt)
+        }
+
     }
 
 }
diff --git a/src/lib.rs b/src/lib.rs
index 2f59f3f..624ce64 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,4 +6,5 @@ pub mod error;
 pub mod iter;
 pub mod result;
 pub mod timetype;
+mod util;
 
diff --git a/src/timetype.rs b/src/timetype.rs
index 67c9229..961a9b3 100644
--- a/src/timetype.rs
+++ b/src/timetype.rs
@@ -15,6 +15,7 @@ use result::Result;
 use error::KairosErrorKind as KEK;
 use error::KairosError as KE;
 use error_chain::ChainedError;
+use util::*;
 
 /// A Type of Time, currently based on chrono::NaiveDateTime
 #[derive(Debug, Clone)]
@@ -32,6 +33,7 @@ pub enum TimeType {
     Subtraction(Box<TimeType>, Box<TimeType>),
 
     EndOfYear(Box<TimeType>),
+    EndOfMonth(Box<TimeType>),
 }
 
 impl Add for TimeType {
@@ -165,6 +167,16 @@ impl TimeType {
         TimeType::EndOfYear(Box::new(self))
     }
 
+    /// Calculate the end of the month based on the current TimeType
+    ///
+    /// # Warning
+    ///
+    /// If the current TimeType does _not_ evaluate to a `TimeType::Moment`, calculating the end of
+    /// the month will fail
+    pub fn end_of_month(self) -> TimeType {
+        TimeType::EndOfMonth(Box::new(self))
+    }
+
     /// Get the number of seconds, if the TimeType is not a duration type, zero is returned
     ///
     /// # Warning
@@ -340,6 +352,7 @@ fn do_calculate(tt: TimeType) -> Result<TimeType> {
         TT::Addition(a, b)    => add(a, b),
         TT::Subtraction(a, b) => sub(a, b),
         TT::EndOfYear(inner)  => end_of_year(*inner),
+        TT::EndOfMonth(inner) => end_of_month(*inner),
         x                     => Ok(x)
     }
 }
@@ -362,6 +375,32 @@ fn end_of_year(tt: TimeType) -> Result<TimeType> {
         els @ TT::Subtraction(_, _) => Err(KE::from_kind(KEK::CannotCalculateEndOfYearOn(els))),
         TT::Moment(m)    => Ok(TT::moment(NaiveDate::from_ymd(m.year(), 12, 31).and_hms(0, 0, 0))),
         TT::EndOfYear(e) => do_calculate(*e),
+        TT::EndOfMonth(e) => do_calculate(*e),
+    }
+}
+
+/// Evaluates the passed argument and if it is a `TT::Moment` it adjust its to the end of the month
+/// else returns an error
+///
+/// Calling a end-of-month on a end-of-month yields end-of-month applied only once.
+fn end_of_month(tt: TimeType) -> Result<TimeType> {
+    use timetype::TimeType as TT;
+
+    match try!(do_calculate(tt)) {
+        els @ TT::Seconds(_)        |
+        els @ TT::Minutes(_)        |
+        els @ TT::Hours(_)          |
+        els @ TT::Days(_)           |
+        els @ TT::Months(_)         |
+        els @ TT::Years(_)          |
+        els @ TT::Addition(_, _)    |
+        els @ TT::Subtraction(_, _) => Err(KE::from_kind(KEK::CannotCalculateEndOfMonthOn(els))),
+        TT::Moment(m)    => {
+            let last_day = get_num_of_days_in_month(m.year(), m.month());
+            Ok(TT::moment(NaiveDate::from_ymd(m.year(), m.month(), last_day).and_hms(0, 0, 0)))
+        },
+        TT::EndOfYear(e) => do_calculate(*e),
+        TT::EndOfMonth(e) => do_calculate(*e),
     }
 }
 
@@ -407,6 +446,9 @@ fn add(a: Box<TimeType>, b: Box<TimeType>) -> Result<TimeType> {
         (TT::EndOfYear(e), other) => Err(KE::from_kind(KEK::CannotAdd(other, TT::EndOfYear(e)))),
         (other, TT::EndOfYear(e)) => Err(KE::from_kind(KEK::CannotAdd(other, TT::EndOfYear(e)))),
 
+        (TT::EndOfMonth(e), other) => Err(KE::from_kind(KEK::CannotAdd(other, TT::EndOfMonth(e)))),
+        (other, TT::EndOfMonth(e)) => Err(KE::from_kind(KEK::CannotAdd(other, TT::EndOfMonth(e)))),
+
         others                           => unimplemented!(),
     }
 }
@@ -423,6 +465,7 @@ fn add_to_seconds(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Years(a)          => Ok(TT::Seconds(a * 60 * 60 * 24 * 30 * 12 + amount)),
         TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Seconds(amount), TT::Moment(m)))),
         TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Seconds(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotAdd(TT::Seconds(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => add_to_seconds(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => add_to_seconds(amount, try!(sub(b, c))),
     }
@@ -440,6 +483,7 @@ fn add_to_minutes(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Years(a)          => Ok(TT::Minutes(a * 60 * 24 * 30 * 12 + amount)),
         TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Minutes(amount), TT::Moment(m)))),
         TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Minutes(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotAdd(TT::Minutes(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => add_to_minutes(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => add_to_minutes(amount, try!(sub(b, c))),
     }
@@ -457,6 +501,7 @@ fn add_to_hours(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Years(a)          => Ok(TT::Hours(  a * 24 * 30 * 12 + amount)),
         TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Hours(amount), TT::Moment(m)))),
         TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Hours(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotAdd(TT::Hours(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => add_to_hours(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => add_to_hours(amount, try!(sub(b, c))),
     }
@@ -474,6 +519,7 @@ fn add_to_days(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Years(a)          => Ok(TT::Days(   a * 30 * 12 + amount)),
         TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Days(amount), TT::Moment(m)))),
         TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Days(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotAdd(TT::Days(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => add_to_days(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => add_to_days(amount, try!(sub(b, c))),
     }
@@ -491,6 +537,7 @@ fn add_to_months(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Years(a)          => Ok(TT::Months( a * 12 + amount)),
         TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Months(amount), TT::Moment(m)))),
         TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Months(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotAdd(TT::Months(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => add_to_months(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => add_to_months(amount, try!(sub(b, c))),
     }
@@ -508,6 +555,7 @@ fn add_to_years(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Years(a)          => Ok(TT::Years(  a + amount)),
         TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Years(amount), TT::Moment(m)))),
         TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Years(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotAdd(TT::Years(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => add_to_years(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => add_to_years(amount, try!(sub(b, c))),
     }
@@ -635,6 +683,7 @@ fn add_to_moment(mom: NaiveDateTime, tt: TimeType) -> Result<TimeType> {
         },
         TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Moment(mom), TT::Moment(m)))),
         TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Moment(mom), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotAdd(TT::Moment(mom), TT::EndOfMonth(e)))),
         TT::Addition(a, b)    => add_to_moment(mom, try!(add(a, b))),
         TT::Subtraction(a, b) => add_to_moment(mom, try!(sub(a, b))),
     }
@@ -694,6 +743,10 @@ fn sub(a: Box<TimeType>, b: Box<TimeType>) -> Result<TimeType> {
         (TT::EndOfYear(e), other) => Err(KE::from_kind(KEK::CannotSub(other, TT::EndOfYear(e)))),
         (other, TT::EndOfYear(e)) => Err(KE::from_kind(KEK::CannotSub(other, TT::EndOfYear(e)))),
 
+        (TT::EndOfMonth(e), other) => Err(KE::from_kind(KEK::CannotSub(other, TT::EndOfMonth(e)))),
+        (other, TT::EndOfMonth(e)) => Err(KE::from_kind(KEK::CannotSub(other, TT::EndOfMonth(e)))),
+
+
         others                           => unimplemented!(),
     }
 }
@@ -708,8 +761,9 @@ fn sub_from_seconds(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Days(a)           => Ok(TT::Seconds(amount - a * 60 * 60 * 24)),
         TT::Months(a)         => Ok(TT::Seconds(amount - a * 60 * 60 * 24 * 30)),
         TT::Years(a)          => Ok(TT::Seconds(amount - a * 60 * 60 * 24 * 30 * 12)),
-        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Seconds(amount), TT::Moment(m)))),
-        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Seconds(amount), TT::EndOfYear(e)))),
+        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotSub(TT::Seconds(amount), TT::Moment(m)))),
+        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Seconds(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotSub(TT::Seconds(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => sub_from_seconds(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => sub_from_seconds(amount, try!(sub(b, c))),
     }
@@ -725,8 +779,9 @@ fn sub_from_minutes(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Days(a)           => Ok(TT::Minutes(amount - a * 60 * 24)),
         TT::Months(a)         => Ok(TT::Minutes(amount - a * 60 * 24 * 30)),
         TT::Years(a)          => Ok(TT::Minutes(amount - a * 60 * 24 * 30 * 12)),
-        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Minutes(amount), TT::Moment(m)))),
-        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Minutes(amount), TT::EndOfYear(e)))),
+        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotSub(TT::Minutes(amount), TT::Moment(m)))),
+        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Minutes(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotSub(TT::Minutes(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => sub_from_minutes(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => sub_from_minutes(amount, try!(sub(b, c))),
     }
@@ -742,8 +797,9 @@ fn sub_from_hours(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Days(a)           => Ok(TT::Hours(amount -   a * 24)),
         TT::Months(a)         => Ok(TT::Hours(amount -   a * 24 * 30)),
         TT::Years(a)          => Ok(TT::Hours(amount -   a * 24 * 30 * 12)),
-        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Hours(amount), TT::Moment(m)))),
-        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Hours(amount), TT::EndOfYear(e)))),
+        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotSub(TT::Hours(amount), TT::Moment(m)))),
+        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Hours(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotSub(TT::Hours(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => sub_from_hours(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => sub_from_hours(amount, try!(sub(b, c))),
     }
@@ -759,8 +815,9 @@ fn sub_from_days(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Days(a)           => Ok(TT::Days(amount -    a)),
         TT::Months(a)         => Ok(TT::Days(amount -    a * 30)),
         TT::Years(a)          => Ok(TT::Days(amount -    a * 30 * 12)),
-        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Days(amount), TT::Moment(m)))),
-        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Days(amount), TT::EndOfYear(e)))),
+        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotSub(TT::Days(amount), TT::Moment(m)))),
+        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Days(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Days(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => sub_from_days(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => sub_from_days(amount, try!(sub(b, c))),
     }
@@ -776,8 +833,9 @@ fn sub_from_months(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Days(a)           => Ok(TT::Days(amount * 30 -    a)),
         TT::Months(a)         => Ok(TT::Months(amount -  a)),
         TT::Years(a)          => Ok(TT::Months(amount -  a * 12)),
-        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Months(amount), TT::Moment(m)))),
-        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Months(amount), TT::EndOfYear(e)))),
+        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotSub(TT::Months(amount), TT::Moment(m)))),
+        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Months(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Months(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => sub_from_months(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => sub_from_months(amount, try!(sub(b, c))),
     }
@@ -793,8 +851,9 @@ fn sub_from_years(amount: i64, tt: TimeType) -> Result<TimeType> {
         TT::Days(a)           => Ok(TT::Days(amount * 12 * 30 -    a)),
         TT::Months(a)         => Ok(TT::Months(amount * 12 -  a)),
         TT::Years(a)          => Ok(TT::Years(amount -   a)),
-        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Years(amount), TT::Moment(m)))),
-        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Years(amount), TT::EndOfYear(e)))),
+        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotSub(TT::Years(amount), TT::Moment(m)))),
+        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Years(amount), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Months(amount), TT::EndOfMonth(e)))),
         TT::Addition(b, c)    => sub_from_years(amount, try!(add(b, c))),
         TT::Subtraction(b, c) => sub_from_years(amount, try!(sub(b, c))),
     }
@@ -945,8 +1004,9 @@ fn sub_from_moment(mom: NaiveDateTime, tt: TimeType) -> Result<TimeType> {
                   .and_hms(h as u32, mi as u32, s as u32);
             Ok(TimeType::moment(tt))
         },
-        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotAdd(TT::Moment(mom), TT::Moment(m)))),
-        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotAdd(TT::Moment(mom), TT::EndOfYear(e)))),
+        TT::Moment(m)         => Err(KE::from_kind(KEK::CannotSub(TT::Moment(mom), TT::Moment(m)))),
+        TT::EndOfYear(e)      => Err(KE::from_kind(KEK::CannotSub(TT::Moment(mom), TT::EndOfYear(e)))),
+        TT::EndOfMonth(e)     => Err(KE::from_kind(KEK::CannotSub(TT::Moment(mom), TT::EndOfMonth(e)))),
         TT::Addition(a, b)    => sub_from_moment(mom, try!(add(a, b))),
         TT::Subtraction(a, b) => sub_from_moment(mom, try!(sub(a, b))),
     }
diff --git a/src/util.rs b/src/util.rs
new file mode 100644
index 0000000..3062c84
--- /dev/null
+++ b/src/util.rs
@@ -0,0 +1,36 @@
+
+#[inline]
+pub fn get_num_of_days_in_month(y: i32, m: u32) -> u32 {
+    if m == 1 || m == 3 || m == 5 || m == 7 || m == 8 || m == 10 || m == 12 {
+        31
+    } else if m == 2 {
+        if is_leap_year(y) {
+            29
+        } else {
+            28
+        }
+    } else {
+        30
+    }
+}
+
+#[inline]
+pub fn is_leap_year(y: i32) -> bool {
+    (y % 4 == 0) && (y % 100 != 0 || y % 400 == 0)
+}
+
+#[test]
+fn test_is_leap_year() {
+    let leaps = [ 1880, 1884, 1888, 1892, 1896, 1904, 1908, 1912, 1916, 1920, 1924, 1928, 1932,
+        1936, 1940, 1944, 1948, 1952, 1956, 1960, 1964, 1968, 1972, 1976, 1980, 1984, 1988, 1992,
+        1996, 2000, 2004, 2008, 2012, 2020, 2024, 2028, 2032, 2036, 2040, 2044, 2048, 2052, 2056,
+        2060, 2064, 2068, 2072, 2076, 2080, 2084, 2088, 2092, 2096, 2104, 2108, 2112, 2116, 2120,
+        2124, 2128, 2132, 2136, 2140, 2144, 2148, 2152, 2156, 2160, 2164, 2168, 2172, 2176, 2180,
+        2184, 2188, 2192, 2196, 2204, 2208 ];
+
+    for i in leaps.iter() {
+        assert!(is_leap_year(*i), "Is no leap year: {}", i);
+        assert!(!is_leap_year(*i + 1), "Seems to be leap year: {}, but should not be", i + 1);
+    }
+
+}