backport src/compojure/api/help.clj

src/compojure/api/help.clj

@@ -0,0 +1,71 @@
+(ns compojure.api.help
+  (:require [schema.core :as s]
+            [clojure.string :as str]))
+
+(def Topic (s/maybe s/Keyword))
+(def Subject (s/maybe (s/cond-pre s/Str s/Keyword s/Symbol)))
+
+;;
+;; content formatting
+;;
+
+(defn text [& s]
+  (->> s
+       (map #(if (seq? %) (apply text %) %))
+       (str/join "\n")))
+
+(defn title [& s]
+  (str "\u001B[32m" (text s) "\u001B[0m"))
+
+(defn code [& s]
+  (str "\u001B[33m" (text s) "\u001B[0m"))
+
+(defmulti help-for (fn [topic subject] [topic subject]) :default ::default)
+
+(defn- subject-text [topic subject]
+  (text
+    ""
+    (title subject)
+    ""
+    (help-for topic subject)
+    ""))
+
+(defn- topic-text [topic]
+  (let [subjects (-> (methods help-for)
+                     (dissoc ::default)
+                     (keys)
+                     (->> (filter #(-> % first (= topic)))))]
+    (text
+      "Topic:\n"
+      (title topic)
+      "\nSubjects:"
+      (->> subjects
+           (map (partial apply subject-text))
+           (map (partial str "\n"))))))
+
+(defn- help-text []
+  (let [methods (dissoc (methods help-for) ::default)]
+    (text
+      "Usage:"
+      ""
+      (code
+        "(help)"
+        "(help topic)"
+        "(help topic subject)")
+      "\nTopics:\n"
+      (title (->> methods keys (map first) (distinct) (sort)))
+      "\nTopics & subjects:\n"
+      (title (->> methods keys (map (partial str/join " ")) (sort))))))
+
+(defmethod help-for ::default [_ _] (help-text))
+
+(s/defn ^:always-validate help
+  ([]
+    (println "------------------------------------------------------------")
+    (println (help-text)))
+  ([topic :- Topic]
+    (println "------------------------------------------------------------")
+    (println (topic-text topic)))
+  ([topic :- Topic, subject :- Subject]
+    (println "------------------------------------------------------------")
+    (println (subject-text topic subject))))