2 files changed, 66 insertions, 1 deletions

diff --git a/rust/schist_models/src/budget_drip.rs b/rust/schist_models/src/budget_drip.rs
index f467ecd..2cc2c63 100644
--- a/rust/schist_models/src/budget_drip.rs
+++ b/rust/schist_models/src/budget_drip.rs
@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::date_utc::DateUtc;
 
-#[derive(Builder, Queryable, Identifiable, Selectable, Debug, PartialEq, Serialize, Deserialize, Insertable)]
+#[derive(Builder, Clone, Copy, Queryable, Identifiable, Selectable, Debug, PartialEq, Serialize, Deserialize, Insertable)]
 #[diesel(table_name = crate::schema::budget_drips)]
 pub struct BudgetDrip {
     pub id: i32,
diff --git a/rust/schist_models/src/date_utc.rs b/rust/schist_models/src/date_utc.rs
index 3f5391c..c801585 100644
--- a/rust/schist_models/src/date_utc.rs
+++ b/rust/schist_models/src/date_utc.rs
@@ -24,6 +24,7 @@ use crate::datetime_utc::DatetimeUtc;
     Serialize,
     Deserialize,
     Clone,
+    Copy,
     Debug,
     AsExpression,
     FromSqlRow,
@@ -55,6 +56,19 @@ impl DateUtc {
             .abs_diff(other.chrono_datetime_utc.num_days_from_ce())
     }
 
+    pub fn days_in_month(&self) -> u32 {
+        self.first_day_in_next_month().day_diff(&self.first_day_in_month())
+    }
+
+    pub fn add_days(&self, days: u64) -> Result<Self> {
+        let chrono_datetime_utc = self
+            .chrono_datetime_utc
+            .checked_add_days(chrono::Days::new(days))
+            .with_context(|| format!("failed to add {} days to {}", days, self))
+            .unwrap();
+        Ok(Self { chrono_datetime_utc })
+    }
+
     fn is_day_str(str: &str) -> bool {
         if str.len() != 10 {
             return false;
@@ -72,6 +86,42 @@ impl DateUtc {
         }
         return true;
     }
+
+    fn first_day_in_next_month(&self) -> Self {
+        let month = self.month();
+        let mut curr_guess: Option<DateTime<Utc>> = None;
+        let mut curr_add = 1;
+        while curr_guess.is_none() || curr_guess.unwrap().month() == month {
+            curr_guess = self.chrono_datetime_utc.checked_add_days(chrono::Days::new(curr_add));
+            curr_add = curr_add + 1;
+        };
+        return Self { chrono_datetime_utc: curr_guess.unwrap() };
+    }
+
+    fn first_day_in_month(&self) -> Self {
+        let month = self.month();
+        let mut prev_guess = self.clone();
+        let mut curr_guess = self.clone();
+        let mut curr_subtractor = 1;
+        while curr_guess.month() == month {
+            prev_guess = curr_guess.clone();
+
+            let mut next: Option<DateTime<Utc>> = None;
+            while next.is_none() {
+                if curr_subtractor > 31 {
+                    return prev_guess;
+                }
+                next = self.chrono_datetime_utc.checked_sub_days(chrono::Days::new(curr_subtractor));
+                curr_subtractor = curr_subtractor + 1;
+            }
+            let next = next.unwrap();
+
+            curr_guess = Self {
+                chrono_datetime_utc: next,
+            };
+        };
+        return prev_guess;
+    }
 }
 
 impl Nowlike for DateUtc {
@@ -306,4 +356,19 @@ mod test {
         assert_eq!(day_diff, 1);
         assert_eq!(day_diff, neg_day_diff);
     }
+
+    #[test]
+    fn test_first_day_in_month() {
+        todo!();
+    }
+
+    #[test]
+    fn test_first_day_in_next_month() {
+        todo!();
+    }
+
+    #[test]
+    fn test_days_in_month() {
+        todo!();
+    }
 }