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todo_server.clj
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todo_server.clj
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(ns erl-like-app.todo.todo-server
(:require
[clojure.core.match :refer [match]]
[taoensso.timbre :as log]
[otplike.process :as process]
[otplike.gen-server :as gen-server]
[erl-like-app.todo.entry :as entry]
[erl-like-app.todo.db :as db]))
;;;;;;;;;;;;; private
(def ^:private SERVER_NAME
:todo)
(defn- call*
;;
([message timeout]
(gen-server/call (process/whereis SERVER_NAME) message timeout))
;;
([message]
(call* message 5000)))
(defn- cast* [message]
(gen-server/cast (process/whereis SERVER_NAME) message))
(defn get-state []
(gen-server/get SERVER_NAME))
;;;;;;;;;;;;; otp
(defn start-link [params]
(gen-server/start-ns [params] {:spawn-opt {:link true
:register SERVER_NAME
:flags {:trap-exit true}}}))
(defn init [_params]
(let [state {:counter 0,
:db {}}]
(log/info (name SERVER_NAME) "server initialized")
[:ok state]))
;;;;;;;;;;;;; API
;; -> [:ok td] | [:error reason]
(defn create-todo [params]
(call* [:create-todo params]))
;; -> [:ok td] | [:error reason]
(defn find-todo-by-id [id]
(call* [:find-todo-by-id id]))
;; -> [:ok updated_td] | [:error reason]
(defn terminate-todo [id]
(call* [:terminate-todo id]))
;; -> [:ok nil] | [:error reason]
(defn delete-todo [id]
(call* [:delete-todo id]))
;; -> [:ok tds] | [:error reason]
(defn enumerate-active-todos []
(call* :enumerate-active-todos))
;;;;;;;;;;;;; core
;; -> [id updated_state]
(defn- next-id [{:keys [counter] :as state}]
[(-> counter inc str)
(update state :counter inc)])
(defn- create-todo* [params state]
(let [[id updated_state] (next-id state)
todo_entry (entry/create id params)
updated_state (-> (db/update-todo todo_entry updated_state) second)
reply (db/find-todo-by-id id updated_state)]
[:reply reply updated_state]))
(defn- find-todo-by-id* [id state]
(let [reply (db/find-todo-by-id id state)]
[:reply reply state]))
(defn- terminate-todo* [id state]
(let [[reply updated_state] (match (db/find-todo-by-id id state)
[:ok loaded]
(let [updated_todo (entry/terminate loaded)
updated_state (-> (db/update-todo updated_todo state) second)]
[(db/find-todo-by-id id updated_state)
updated_state])
([:error reason] :as r)
[r state])]
[:reply reply updated_state]))
(defn- delete-todo* [id state]
(let [updated_state (-> (db/delete-todo id state) second)
reply [:ok nil]]
[:reply reply updated_state]))
(defn- enumerate-active-todos* [state]
(let [reply (db/enumerate-active-todos state)]
[:reply reply state]))
;;;;;;;;;;;;; otp
(defn handle-call [message _from state]
(match message
[:create-todo params]
(create-todo* params state)
[:find-todo-by-id id]
(find-todo-by-id* id state)
[:terminate-todo id]
(terminate-todo* id state)
[:delete-todo id]
(delete-todo* id state)
:enumerate-active-todos
(enumerate-active-todos* state)))
(defn handle-cast [message state]
(log/error "unknown cast:" message)
[:noreply state])
(defn handle-info [message state]
(log/error "unknown info:" message)
[:noreply state])
(defn terminate [_reason _state]
(log/info (name SERVER_NAME) "server stopped"))