# Copyright 2017-2018 (C) Calvin Rose

(do

  (var *should-repl* :private false)
  (var *no-file* :private true)
  (var *raw-stdin* :private false)
  (var *handleopts* :private true)
  (var *exit-on-error* :private true)

  # Flag handlers
  (def handlers :private 
    {"h" (fn [] 
           (print "usage: " (get args 0) " [options] scripts...")
           (print 
             `Options are:
  -h Show this help
  -v Print the version string
  -s Use raw stdin instead of getline like functionality
  -e Execute a string of dst
  -r Enter the repl after running all scripts
  -p Keep on executing if there is a top level error (persistent)
  -- Stop handling options`)
           (os.exit 0)
           1)
     "v" (fn @[] (print dst.version) (os.exit 0) 1)
     "s" (fn @[] (:= *raw-stdin* true) (:= *should-repl* true) 1)
     "r" (fn @[] (:= *should-repl* true) 1)
     "p" (fn @[] (:= *exit-on-error* false) 1)
     "-" (fn @[] (:= *handleopts* false) 1)
     "e" (fn @[i] 
           (:= *no-file* false)
           (eval (get args (+ i 1)))
           2)})

  (defn- dohandler @[n i]
    (def h (get handlers n))
    (if h (h i) (print "unknown flag -" n)))

  # Process arguments
  (var i 1)
  (def lenargs (length args))
  (while (< i lenargs)
    (def arg (get args i))
    (if (and *handleopts* (= "-" (string.slice arg 0 1)))
      (+= i (dohandler (string.slice arg 1 2) i))
      (do
        (:= *no-file* false)
        (import* _env arg :exit *exit-on-error*)
        (++ i))))

  (when (or *should-repl* *no-file*) 
    (if *raw-stdin*
      (repl nil identity)
      (do
        (print (string "Dst " dst.version "  Copyright (C) 2017-2018 Calvin Rose"))
        (repl (fn [buf p]
                (def [line] (parser.where p))
                (def prompt (string "dst:" line ":" (parser.state p) "> "))
                (getline prompt buf)))))))