Add issue creation and editing

crates/app/src/domain.rs

@@ -139,6 +139,20 @@ pub struct IssueDetails {
     pub comments: Vec<models::Comment>,
 }
 
+pub struct IssueEditorData {
+    pub issue: Option<models::Issue>,
+    pub labels: Vec<models::Label>,
+    pub milestones: Vec<models::Milestone>,
+}
+
+pub struct IssueDraft {
+    pub title: String,
+    pub body: String,
+    pub label_ids: Vec<i64>,
+    pub milestone_id: Option<i64>,
+    pub due_date: Option<i64>,
+}
+
 pub struct MilestoneDetails {
     pub milestone: models::Milestone,
     pub issues: Vec<models::Issue>,
@@ -155,6 +169,49 @@ pub fn open_status() -> String {
     "open".into()
 }
 
+pub fn civil_from_days(days: i64) -> (i64, i64, i64) {
+    let days = days + 719_468;
+    let era = days.div_euclid(146_097);
+    let day_of_era = days - era * 146_097;
+    let year_of_era =
+        (day_of_era - day_of_era / 1_460 + day_of_era / 36_524 - day_of_era / 146_096) / 365;
+    let mut year = year_of_era + era * 400;
+    let day_of_year = day_of_era - (365 * year_of_era + year_of_era / 4 - year_of_era / 100);
+    let month_prime = (5 * day_of_year + 2) / 153;
+    let day = day_of_year - (153 * month_prime + 2) / 5 + 1;
+    let month = month_prime + if month_prime < 10 { 3 } else { -9 };
+    year += i64::from(month <= 2);
+    (year, month, day)
+}
+
+pub fn days_from_civil(mut year: i64, month: i64, day: i64) -> i64 {
+    year -= i64::from(month <= 2);
+    let era = year.div_euclid(400);
+    let year_of_era = year - era * 400;
+    let month_prime = month + if month > 2 { -3 } else { 9 };
+    let day_of_year = (153 * month_prime + 2) / 5 + day - 1;
+    let day_of_era = year_of_era * 365 + year_of_era / 4 - year_of_era / 100 + day_of_year;
+    era * 146_097 + day_of_era - 719_468
+}
+
+pub fn api_date(timestamp: i64) -> String {
+    let (year, month, day) = civil_from_days(timestamp.div_euclid(86_400));
+    format!("{year:04}-{month:02}-{day:02}T00:00:00Z")
+}
+
+pub fn parse_api_date(value: &str) -> Option<i64> {
+    let date = value.get(..10)?;
+    let mut parts = date.split('-');
+    let year = parts.next()?.parse().ok()?;
+    let month = parts.next()?.parse().ok()?;
+    let day = parts.next()?.parse().ok()?;
+    if parts.next().is_some() || !(1..=12).contains(&month) || !(1..=31).contains(&day) {
+        return None;
+    }
+    let days = days_from_civil(year, month, day);
+    (civil_from_days(days) == (year, month, day)).then_some(days * 86_400)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -179,4 +236,12 @@ mod tests {
             .is_active("open")
         );
     }
+
+    #[test]
+    fn issue_dates_round_trip_and_reject_invalid_dates() {
+        let leap_day = parse_api_date("2024-02-29T12:34:56Z").unwrap();
+        assert_eq!(api_date(leap_day), "2024-02-29T00:00:00Z");
+        assert_eq!(parse_api_date("2023-02-29T00:00:00Z"), None);
+        assert_eq!(parse_api_date("not-a-date"), None);
+    }
 }