(ns myapp.component.handler
  (:require [com.stuartsierra.component :as component]
            [compojure.core :as compojure]
            [jdbc-ring-session.core :refer [jdbc-store]]))

(defn- find-routes [component]
  (keep :routes (vals component)))

(defn- middleware-fn [component middleware]
  (if (vector? middleware)
    (let [[f & keys] middleware
          arguments  (map #(get component %) keys)]
      #(apply f % arguments))
    middleware))

(defn- compose-middleware [{:keys [middleware] :as component}]
  (->> (reverse middleware)
       (map #(middleware-fn component %))
       (apply comp identity)))

(defrecord Handler [defaults db middleware]
  component/Lifecycle
  (start [component]
    (let [component (-> component
                        (assoc-in [:defaults
                                   :session
                                   :store]
                                  (jdbc-store (:spec db))))]
      (if-not (:handler component)
        (let [routes  (find-routes component)
              wrap-mw (compose-middleware component)
              handler (wrap-mw (apply compojure/routes routes))]
          (assoc component :handler handler))
        component)))
  (stop [component]
    (dissoc component :handler)))

(defn handler-component [options]
    (map->Handler options))