Reorganize spec evaluation

src/eval/command/date.rs

@@ -0,0 +1,59 @@
+use chrono::NaiveDate;
+
+use crate::files::commands::{self, Spanned, Time};
+
+use super::super::command::CommandState;
+use super::super::delta::{Delta, DeltaStep};
+use super::super::Result;
+
+pub struct DateSpec {
+    pub start: NaiveDate,
+    pub start_delta: Delta,
+    pub start_time: Option<Time>,
+    pub end_delta: Delta,
+    pub repeat: Option<Delta>,
+    pub start_at_done: bool,
+}
+
+impl From<&commands::DateSpec> for DateSpec {
+    fn from(spec: &commands::DateSpec) -> Self {
+        let start_delta: Delta = spec
+            .start_delta
+            .as_ref()
+            .map(|delta| delta.into())
+            .unwrap_or_default();
+
+        let mut end_delta: Delta = spec
+            .end_delta
+            .as_ref()
+            .map(|delta| delta.into())
+            .unwrap_or_default();
+        if let Some(time) = spec.end_time {
+            end_delta
+                .steps
+                .push(Spanned::new(time.span, DeltaStep::Time(time.value)));
+        }
+
+        let repeat: Option<Delta> = spec.repeat.as_ref().map(|repeat| (&repeat.delta).into());
+        let start_at_done = spec
+            .repeat
+            .as_ref()
+            .map(|repeat| repeat.start_at_done)
+            .unwrap_or(false);
+
+        Self {
+            start: spec.start,
+            start_delta,
+            start_time: spec.start_time,
+            end_delta,
+            repeat,
+            start_at_done,
+        }
+    }
+}
+
+impl<'a> CommandState<'a> {
+    pub fn eval_date_spec(&mut self, spec: DateSpec) -> Result<()> {
+        todo!()
+    }
+}