5 files changed, 86 insertions, 3 deletions

diff --git a/src/app/cursor.rs b/src/app/cursor.rs
new file mode 100644
index 0000000..ed6bd65
--- /dev/null
+++ b/src/app/cursor.rs
@@ -0,0 +1,51 @@
+use chrono::{Duration, Local, NaiveDate};
+use cursive::direction::Absolute;
+
+#[derive(Debug, Copy, Clone)]
+pub struct Cursor(pub NaiveDate);
+
+impl std::default::Default for Cursor {
+    fn default() -> Self {
+        Cursor::new()
+    }
+}
+
+impl Cursor {
+    pub fn new() -> Self {
+        Cursor {
+            0: Local::now().naive_local().date(),
+        }
+    }
+    pub fn do_move(&mut self, d: Absolute) {
+        let today = Local::now().naive_local().date();
+        let cursor = self.0;
+        match d {
+            Absolute::Right => {
+                // forward by 1 day
+                let next = cursor.succ_opt().unwrap_or(cursor);
+                if next <= today {
+                    self.0 = next;
+                }
+            }
+            Absolute::Left => {
+                // backward by 1 day
+                // assumes an infinite past
+                self.0 = cursor.pred_opt().unwrap_or(cursor);
+            }
+            Absolute::Down => {
+                // forward by 1 week
+                let next = cursor.checked_add_signed(Duration::weeks(1)).unwrap();
+                if next <= today {
+                    self.0 = next;
+                }
+            }
+            Absolute::Up => {
+                // backward by 1 week
+                // assumes an infinite past
+                let next = cursor.checked_sub_signed(Duration::weeks(1)).unwrap();
+                self.0 = next;
+            }
+            Absolute::None => {}
+        }
+    }
+}
diff --git a/src/app/impl_self.rs b/src/app/impl_self.rs
index 1114d50..abf5209 100644
--- a/src/app/impl_self.rs
+++ b/src/app/impl_self.rs
@@ -15,7 +15,7 @@ use crate::command::{Command, CommandLineError};
 use crate::habit::{Bit, Count, HabitWrapper, TrackEvent, ViewMode};
 use crate::utils::{self, GRID_WIDTH, VIEW_HEIGHT, VIEW_WIDTH};
 
-use crate::app::{App, MessageKind, StatusLine};
+use crate::app::{App, Cursor, Message, MessageKind, StatusLine};
 
 impl App {
     pub fn new() -> Self {
@@ -28,7 +28,8 @@ impl App {
             _file_watcher: watcher,
             file_event_recv: rx,
             view_month_offset: 0,
-            message: "Type :add <habit-name> <goal> to get started, Ctrl-L to dismiss".into(),
+            cursor: Cursor::new(),
+            message: Message::startup(),
         };
     }
 
@@ -85,6 +86,13 @@ impl App {
         }
     }
 
+    pub fn move_cursor(&mut self, d: Absolute) {
+        self.cursor.do_move(d);
+        for v in self.habits.iter_mut() {
+            v.move_cursor(d);
+        }
+    }
+
     pub fn set_focus(&mut self, d: Absolute) {
         match d {
             Absolute::Right => {
@@ -129,7 +137,7 @@ impl App {
             format!("{}", Local::now().naive_local().date().format("%d/%b/%y"),)
         } else {
             let months = self.view_month_offset;
-            format!("{}", format!("{} months ago", months),)
+            format!("{}", format!("{} month(s) ago", months),)
         };
 
         StatusLine {
diff --git a/src/app/impl_view.rs b/src/app/impl_view.rs
index 395cac4..0ec47f1 100644
--- a/src/app/impl_view.rs
+++ b/src/app/impl_view.rs
@@ -95,6 +95,24 @@ impl View for App {
                 self.set_focus(Absolute::Down);
                 return EventResult::Consumed(None);
             }
+
+            Event::Char('w') => {
+                self.move_cursor(Absolute::Up);
+                return EventResult::Consumed(None);
+            }
+            Event::Char('a') => {
+                self.move_cursor(Absolute::Left);
+                return EventResult::Consumed(None);
+            }
+            Event::Char('s') => {
+                self.move_cursor(Absolute::Down);
+                return EventResult::Consumed(None);
+            }
+            Event::Char('d') => {
+                self.move_cursor(Absolute::Right);
+                return EventResult::Consumed(None);
+            }
+
             Event::Char('v') => {
                 if self.habits.is_empty() {
                     return EventResult::Consumed(None);
diff --git a/src/app/message.rs b/src/app/message.rs
index 65f0a5c..a1d3d57 100644
--- a/src/app/message.rs
+++ b/src/app/message.rs
@@ -35,6 +35,9 @@ pub struct Message {
 }
 
 impl Message {
+    pub fn startup() -> Self {
+        "Type :add <habit-name> <goal> to get started, Ctrl-L to dismiss".into()
+    }
     pub fn contents(&self) -> &str {
         &self.msg
     }
diff --git a/src/app/mod.rs b/src/app/mod.rs
index 2aecb33..9432f0d 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -5,11 +5,13 @@ use notify::{DebouncedEvent, RecommendedWatcher};
 
 use crate::habit::HabitWrapper;
 
+mod cursor;
 mod impl_self;
 mod impl_view;
 mod message;
 
 pub struct StatusLine(String, String);
+pub use cursor::Cursor;
 pub use message::{Message, MessageKind};
 
 pub struct App {
@@ -20,6 +22,7 @@ pub struct App {
     file_event_recv: Receiver<DebouncedEvent>,
     focus: usize,
     view_month_offset: u32,
+    cursor: Cursor,
     message: Message,
 }