;;;; Entry point for the clarence application
;; Clarence is a unix filter, meaning it consumes a stream and outputs a
;; transformed stream.

(defpackage :clarence/main
  (:use :cl :net.acdw.clarence)
  (:export #:main))

(in-package :clarence/main)

(defun clarence/command ()
  "Creates and returns the top-level command."
  (clingon:make-command
   :name "clarence"
   :description "A gemtext converter for other formats"
   :version "1780.4"
   :license "BSD 3-Clause"
   :authors '("Case Duckworth <acdw@acdw.net>")
   :usage "[-t FORMAT] [-o FILE] [FILE]"
   :options (clarence/options)
   :handler #'clarence/handler))

(defun clarence/options ()
  "The command-line options for `clarence' command."
  (list (clingon:make-option
         :string
         :description "Output format"
         :short-name #\t
         :long-name "to"
         :initial-value "gemtext"
         :key :to)
        (clingon:make-option
         :filepath
         :description "Output file"
         :short-name #\o
         :long-name "output"
         :key :output)))

(defun clarence/handler (cmd)
  "The top-level handler."
  (let ((input-file (car (clingon:command-arguments cmd)))
        (input-stream *standard-input*)
        (output-format  (clingon:getopt cmd :to))
        (output-file (clingon:getopt cmd :output))
        (output-stream *standard-output*))
    (when input-file
      (setf input-stream (open input-file :direction :input)))
    (when output-file
      (setf output-stream (open output-file :direction :output)))
    (princ (document-string (parse input-stream) :writer output-format)
           output-stream)
    (close input-stream)
    (close output-stream)))

(defun main ()
  (let ((app (clarence/command)))
    (clingon:run app)))