From 191b5354795e869f9dd88bc83e1a728cfb570e6e Mon Sep 17 00:00:00 2001
From: Matthias Beyer <mail@beyermatthias.de>
Date: Sun, 30 Jun 2019 11:24:06 +0200
Subject: [PATCH] Change HabitInstance implementation to not contain comment in
 instance

This patch changes the HabitInstance implementation so that the comment
is not expected to exist in the instance object itself.

This is done for less data duplication.

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>
---
 lib/domain/libimaghabit/src/instance.rs | 49 +++++++++++++++++++------
 1 file changed, 37 insertions(+), 12 deletions(-)

diff --git a/lib/domain/libimaghabit/src/instance.rs b/lib/domain/libimaghabit/src/instance.rs
index 2255afdf..b5a0443b 100644
--- a/lib/domain/libimaghabit/src/instance.rs
+++ b/lib/domain/libimaghabit/src/instance.rs
@@ -17,16 +17,21 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 //
 
+use std::ops::Deref;
+
 use chrono::NaiveDate;
 use toml::Value;
 use toml_query::set::TomlValueSetExt;
 use failure::Fallible as Result;
 
 use crate::util::*;
+use crate::habit::HabitTemplate;
 
 use libimagstore::store::Entry;
+use libimagstore::store::Store;
 use libimagentryutil::isa::Is;
 use libimagentryutil::isa::IsKindHeaderPathProvider;
+use libimagentrylink::linkable::Linkable;
 
 /// An instance of a habit is created for each time a habit is done.
 ///
@@ -41,8 +46,7 @@ pub trait HabitInstance {
 
     fn get_date(&self) -> Result<NaiveDate>;
     fn set_date(&mut self, n: &NaiveDate) -> Result<()>;
-    fn get_comment(&self) -> Result<String>;
-    fn set_comment(&mut self, c: String) -> Result<()>;
+    fn get_comment(&self, store: &Store) -> Result<String>;
     fn get_template_name(&self) -> Result<String>;
 }
 
@@ -68,16 +72,37 @@ impl HabitInstance for Entry {
             .map(|_| ())
     }
 
-    fn get_comment(&self) -> Result<String> {
-        get_string_header_from_entry(self, "habit.instance.comment")
-    }
-
-    fn set_comment(&mut self, c: String) -> Result<()> {
-        // Using `set` here because when creating the entry, these headers should be made present.
-        self.get_header_mut()
-            .set("habit.instance.comment", Value::String(c))
-            .map_err(From::from)
-            .map(|_| ())
+    /// Iterates all internal links, finds the template for this instance and gets the comment from
+    /// it
+    ///
+    ///
+    /// # Warning
+    ///
+    /// Internally tries to `Store::get()` the template entry. If this entry is borrowed outside of
+    /// this function, this fails.
+    ///
+    /// If multiple templates are linked to this entry, this returns the comment of the first
+    ///
+    ///
+    /// # Return
+    ///
+    /// Returns the Comment string from the first template that is linked to this instance.
+    /// If this is not an instance, this might misbehave.
+    /// If there is no template linked, this returns an error.
+    ///
+    fn get_comment(&self, store: &Store) -> Result<String> {
+        let templ_name = self.get_template_name()?;
+        for link in self.links()? {
+            let template = store.get(link.get_store_id().clone())?.ok_or_else(|| {
+                format_err!("Entry {} is linked to {}, but that entry does not exist",
+                            self.get_location(),
+                            link.get_store_id())
+            })?;
+            if HabitTemplate::is_habit_template(template.deref())? && template.habit_name()? == templ_name {
+                return template.habit_comment()
+            }
+        }
+        Err(format_err!("Cannot find template entry for {}", self.get_location()))
     }
 
     fn get_template_name(&self) -> Result<String> {