#!/usr/bin/env bb
#_" -*- mode: clojure; -*-"
;; Source: https://gist.github.com/holyjak/36c6284c047ffb7573e8a34399de27d8

;; Based on https://github.com/babashka/babashka/blob/master/examples/image_viewer.clj
(ns file-server
  (:require [babashka.fs :as fs]
            [clojure.java.browse :as browse]
            [clojure.string :as str]
            [clojure.tools.cli :refer [parse-opts]]
            [hiccup2.core :as html]
            [org.httpkit.server :as server])
  (:import [java.net URLDecoder URLEncoder]))

(def cli-options [["-p" "--port PORT" "Port for HTTP server" :default 8090 :parse-fn #(Integer/parseInt %)]
                  ["-d" "--dir DIR" "Directory to serve files from" :default "."]
                  ["-h" "--help" "Print usage info"]])

(def parsed-args (parse-opts *command-line-args* cli-options))
(def opts (:options parsed-args))

(cond
  (:help opts)
  (do (println "Start a http server for static files in the given dir. Usage:\n" (:summary parsed-args))
      (System/exit 0))

  (:errors parsed-args)
  (do (println "Invalid arguments:\n" (str/join "\n" (:errors parsed-args)))
      (System/exit 1))

  :else
  :continue)


(def port (:port opts))
(def dir (fs/path (:dir opts)))

(assert (fs/directory? dir) (str "The given dir `" dir "` is not a directory."))

(defn index [f]
  (let [files (map #(str (.relativize dir %))
                   (fs/list-dir f))]
    {:body (-> [:html
                [:head
                 [:meta {:charset "UTF-8"}]
                 [:title (str "Index of `" f "`")]]
                [:body
                 [:h1 "Index of " [:code (str f)]]
                 [:ul
                  (for [child files]
                    [:li [:a {:href (URLEncoder/encode (str child))} child
                          (when (fs/directory? (fs/path dir child)) "/")]])]
                 [:hr]
                 [:footer {:style {"text-aling" "center"}} "Served by http-server.clj"]]]
               html/html
               str)}))

(defn body [path]
  {:body (fs/file path)})

(server/run-server
 (fn [{:keys [:uri]}]
   (let [f (fs/path dir (str/replace-first (URLDecoder/decode uri) #"^/" ""))
         index-file (fs/path f "index.html")]
     (cond
       (and (fs/directory? f) (fs/readable? index-file))
       (body index-file)

       (fs/directory? f)
       (index f)

       (fs/readable? f)
       (body f)

       :else
       {:status 404 :body (str "Not found `" f "` in " dir)})))
 {:port port})

(println "Starting http server at " port "for" (str dir))
(browse/browse-url (format "http://localhost:%s/" port))

@(promise)