routes.knot

with {
data Priority = Low {} | Medium {} | High {} | Critical {}

type Todo = {title: Text, owner: Text, priority: Priority}

*todos : [Todo]

api Api where
  GetTodos get /todos/{owner: Text} @{xForwardedFor: Maybe Text} -> [Todo]
  CreateTodo post /todos ={title: Text, owner: Text, priority: Text} -> Todo
  GetCount get /admin/count -> Int 1

addTodo (\title owner priority -> do
  todos <- full *todos
  *todos = base.union todos [{title title owner owner priority (Priority.Low {})}])

getTodos (\owner -> do
  todos <- full *todos
  with {result (do t <- todos; where t.owner == owner; yield t)} yield result)

srv (serve Api where
  GetTodos = \{owner owner xForwardedFor xForwardedFor} -> do
    case xForwardedFor of
      Maybe.Just {value ip} -> base.logInfo ("GetTodos from " ++ ip)
      Maybe.Nothing {} -> base.logInfo "GetTodos (no proxy header)"
    todos <- getTodos owner
    case base.count todos == 0 of
      Bool.True {} -> yield (Result.Err {error {status 404 message "no todos found for owner"}})
      Bool.False {} -> yield (Result.Ok {value todos})
  CreateTodo = \{title title owner owner priority priority} -> do
    addTodo title owner priority
    yield (Result.Ok {value {title title owner owner priority (Priority.Low {})}})
  GetCount = \{} -> do
    todos <- full *todos
    yield (Result.Ok {value (base.count todos)}))
}
(base.listen 8080 srv)