;; This Source Code Form is subject to the terms of the Mozilla Public
;; License, v. 2.0. If a copy of the MPL was not distributed with this
;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
;;
;; Copyright (c) KALEIDOS INC

(ns app.rpc.doc
  "API autogenerated documentation."
  (:require
   [app.common.data :as d]
   [app.config :as cf]
   [app.rpc :as-alias rpc]
   [app.util.services :as sv]
   [app.util.template :as tmpl]
   [clojure.java.io :as io]
   [clojure.spec.alpha :as s]
   [cuerdas.core :as str]
   [integrant.core :as ig]
   [pretty-spec.core :as ps]
   [yetti.response :as yrs]))

(defn- get-spec-str
  [k]
  (with-out-str
    (ps/pprint (s/form k)
               {:ns-aliases {"clojure.spec.alpha" "s"
                             "clojure.core.specs.alpha" "score"
                             "clojure.core" nil}})))

(defn- prepare-context
  [methods]
  (letfn [(gen-doc [type [name f]]
            (let [mdata (meta f)]
              {:type (d/name type)
               :name (d/name name)
               :module (-> (:ns mdata) (str/split ".") last)
               :auth (:auth mdata true)
               :docs (::sv/docstring mdata)
               :deprecated (::deprecated mdata)
               :added (::added mdata)
               :changes (some->> (::changes mdata) (partition-all 2) (map vec))
               :spec (get-spec-str (::sv/spec mdata))}))]

    {:version (:main cf/version)
     :command-methods
     (->> (:commands methods)
          (map (partial gen-doc :command))
          (sort-by (juxt :module :name)))

     :query-methods
     (->> (:queries methods)
          (map (partial gen-doc :query))
          (sort-by (juxt :module :name)))
     :mutation-methods
     (->> (:mutations methods)
          (map (partial gen-doc :query))
          (sort-by (juxt :module :name)))}))

(defn- handler
  [methods]
  (if (contains? cf/flags :backend-api-doc)
    (let [context (prepare-context methods)]
      (fn [_ respond _]
        (respond (yrs/response 200 (-> (io/resource "app/templates/api-doc.tmpl")
                                       (tmpl/render context))))))
    (fn [_ respond _]
      (respond (yrs/response 404)))))


(defmethod ig/pre-init-spec ::routes [_]
  (s/keys :req-un [::rpc/methods]))

(defmethod ig/init-key ::routes
  [_ {:keys [methods] :as cfg}]
  ["/_doc" {:handler (handler methods)
            :allowed-methods #{:get}}])