Refractor file writing and implement delete feature.

src/habitmgr.rs

@@ -40,7 +40,6 @@ impl HabitMgr
 		 */
 		if !habits_path.is_file()
 		{
-			println!("First launch: creating files.");
 			let habits_file = OpenOptions::new()
 				.create(true)
 				.write(true)
@@ -75,9 +74,8 @@ impl HabitMgr
 		self.habits = serde_json::from_reader(habits_reader).unwrap();
 	}
 
-	pub fn add(&mut self, name:String, bad:bool, weight:u8, _days:String)
+	fn write_habits(&self)
 	{
-		self.import_habits();
 		let habits_file = OpenOptions::new()
 			.truncate(true)
 			.write(true)
@@ -85,18 +83,31 @@ impl HabitMgr
 			.unwrap_or_else(|e| {
 				panic!("Error opening file {}:\n{}", self.habits_path.display(), e);
 			});
-
-		self.habits.push(Habit::new(name.clone(), bad, weight));
 		let habits_writer = BufWriter::new(habits_file);
 		serde_json::to_writer(habits_writer, &self.habits)
 			.unwrap_or_else(|e| {
 					panic!("Error writing to file {}:\n{}",
 								 self.habits_path.display(), e);
 			});
+	}
+
+	pub fn add(&mut self, name:String, bad:bool, weight:u8, _days:String)
+	{
+		self.import_habits();
+		self.habits.push(Habit::new(name.clone(), bad, weight));
+		self.write_habits();
 
 		println!("New habit {} added.", &name);
 	}
 
+	pub fn delete(&mut self, id:usize)
+	{
+		self.import_habits();
+		let old_habit = self.habits.remove(id);
+		self.write_habits();
+		println!("Removed habit {}", old_habit.get_name());
+	}
+
 	pub fn list(&mut self, all:bool, verbose:bool)
 	{
 		self.import_habits();

src/main.rs

@@ -62,8 +62,11 @@ enum Command
 	},
 	#[structopt(alias = "mod")]
 	Modify { },
-	#[structopt(alias = "rm")]
+	#[structopt(alias = "del")]
-	Remove { },
+	Delete {
+		#[structopt(help = "ID of the habit to delete")]
+		id:usize,
+	},
 	#[structopt(alias = "stats")]
 	Statistics { },
 }
@@ -102,6 +105,8 @@ fn main()
 					hmgr.add(name, bad, weight, days),
 				Command::List { all, verbose } =>
 					hmgr.list(all, verbose),
+				Command::Delete { id } =>
+					hmgr.delete(id),
 				_ => todo!(),
 			},
 	}