48 lines
1.3 KiB
Elixir
48 lines
1.3 KiB
Elixir
|
defmodule TodoList do
|
||
|
|
defstruct auto_id: 1, entries: %{}
|
||
|
|
|
||
|
|
def new(), do: %TodoList{}
|
||
|
|
|
||
|
|
def add_entry(todo_list, entry) do
|
||
|
|
entry = Map.put(entry, :id, todo_list.auto_id)
|
||
|
|
|
||
|
|
new_entries =
|
||
|
|
Map.put(
|
||
|
|
todo_list.entries,
|
||
|
|
todo_list.auto_id,
|
||
|
|
entry
|
||
|
|
)
|
||
|
|
|
||
|
|
%TodoList{todo_list | entries: new_entries, auto_id: todo_list.auto_id + 1}
|
||
|
|
end
|
||
|
|
|
||
|
|
def entries(todo_list, date) do
|
||
|
|
todo_list.entries
|
||
|
|
|> Stream.filter(fn {_, entry} -> entry.date == date end)
|
||
|
|
|> Enum.map(fn {_, entry} -> entry end)
|
||
|
|
end
|
||
|
|
|
||
|
|
def update_entry(todo_list, %{} = new_entry) do
|
||
|
|
update_entry(todo_list, new_entry.id, fn _ -> new_entry end)
|
||
|
|
end
|
||
|
|
|
||
|
|
def update_entry(todo_list, entry_id, updater_fun) do
|
||
|
|
case Map.fetch(todo_list.entries, entry_id) do
|
||
|
|
:error ->
|
||
|
|
todo_list
|
||
|
|
|
||
|
|
{:ok, old_entry} ->
|
||
|
|
old_entry_id = old_entry.id
|
||
|
|
# Make sure that the result of the updater is a map and the
|
||
|
|
# id remains unchanged.
|
||
|
|
new_entry = %{id: ^old_entry_id} = updater_fun.(old_entry)
|
||
|
|
new_entries = Map.put(todo_list.entries, new_entry.id, new_entry)
|
||
|
|
%TodoList{todo_list | entries: new_entries}
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
def delete_entry(todo_list, entry_id) do
|
||
|
|
%TodoList{todo_list | entries: Map.delete(todo_list.entries, entry_id)}
|
||
|
|
end
|
||
|
|
end
|