Let "today" command list upcoming habits

bin/domain/imag-habit/src/main.rs

@@ -125,6 +125,9 @@ fn delete(rt: &Runtime) {
 // Almost the same as `list()` but with other lister functions and an additional filter for only
 // listing entries which are due today.
 fn today(rt: &Runtime) {
+    use libimaghabit::error::ResultExt;
+    use libimaghabit::error::HabitErrorKind as HEK;
+
     fn lister_fn(h: &FileLockEntry) -> Vec<String> {
         debug!("Listing: {:?}", h);
         let name     = h.habit_name().map_err_trace_exit_unwrap(1);
@@ -143,7 +146,8 @@ fn today(rt: &Runtime) {
 
     let today = ::chrono::offset::Local::today().naive_local();
 
-    let today_relevant : Vec<_> = rt
+    let relevant : Vec<_> = { // scope, to have variable non-mutable in outer scope
+        let mut relevant : Vec<_> = rt
             .store()
             .all_habit_templates()
             .map_err_trace_exit_unwrap(1)
@@ -160,17 +164,49 @@ fn today(rt: &Runtime) {
             })
             .filter(|h| {
                 let due = h.next_instance_date().map_err_trace_exit_unwrap(1);
-            due == today
+                due == today || due > today // today or in future
             })
             .collect();
 
-    if today_relevant.is_empty() {
+        relevant.sort_by_key(|h| h.next_instance_date().map_err_trace_exit_unwrap(1));
+        relevant
+    };
+
+    let any_today_relevant = relevant
+        .iter()
+        .filter(|h| {
+            let due = h.next_instance_date().map_err_trace_exit_unwrap(1);
+            due == today // relevant today
+        })
+        .count() == 0;
+
+    if any_today_relevant {
+        let n = rt
+            .cli()
+            .subcommand_matches("today")
+            .and_then(|am| {
+                am.value_of("today-show-next-n")
+                    .map(|x| {
+                        x.parse::<usize>()
+                            .chain_err(|| HEK::from(format!("Cannot parse String '{}' to integer", x)))
+                            .map_err_trace_exit_unwrap(1)
+                    })
+            }).unwrap_or(5);
+
         info!("No Habits due today.");
+        info!("Upcoming:");
+        // list `n` which are relevant in the future.
+        for element in relevant.iter().take(n) {
+            let date = element.next_instance_date().map_err_trace_exit_unwrap(1);
+            let name = element.habit_name().map_err_trace_exit_unwrap(1);
+
+            info!(" * {date}: {name}", date = date, name = name);
+        }
     } else {
         TableLister::new(lister_fn)
             .with_header(lister_header())
             .with_idx(true)
-            .list(today_relevant.into_iter())
+            .list(relevant.into_iter())
             .map_err_trace_exit_unwrap(1);
     }
 }

bin/domain/imag-habit/src/ui.rs

@@ -111,5 +111,13 @@ pub fn build_ui<'a>(app: App<'a, 'a>) -> App<'a, 'a> {
         .subcommand(SubCommand::with_name("today")
                    .about("List habits which are due today")
                    .version("0.1")
+                   .arg(Arg::with_name("today-show-next-n")
+                        .long("show")
+                        .short("s")
+                        .multiple(false)
+                        .required(false)
+                        .takes_value(true)
+                        .value_name("N")
+                        .help("Show the N next relevant entries. Default = 5"))
                    )
 }