;; cli.lisp -- Command line interface entry point and option parsing
;; Copyright (C) 2024  Alexander Rosenberg
;;
;; This program is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
(defpackage #:truth-table/cli
  (:use #:common-lisp #:truth-table/base
        #:truth-table/args)
  (:export #:toplevel #:main))

(in-package :truth-table/cli)

(defun eval-and-typeset-propositions (prop-strs &key (format "unicode")
                                                  (implicit-and t)
                                                  multi-char-names
                                                  include-intermediate
                                                  (include-vars t))
  "Evaluate and then typeset PROP-STRS as a table, which is a list of
proposition strings. For a description of the key parameters, see each of the
functions involved in evaluating and typesetting."
  (loop with vars = '()
        for prop-str in prop-strs
        for (parsed-exp parsed-vars)
          = (multiple-value-list
             (parse-proposition-string prop-str
                                       :implicit-and implicit-and
                                       :multi-char-names multi-char-names))
        collect parsed-exp into exps
        do (dolist (var parsed-vars)
             (unless (member var vars :test 'equal)
               (setq vars (nconc vars (list var)))))
        finally
           (let ((table (create-combined-truth-table
                         exps vars
                         :include-intermediate include-intermediate
                         :include-vars include-vars)))
             (return (typeset-table-to-format table format)))))

(defparameter *command-line-spec*
  '((#\h "help" help nil "print this message, then exit")
    (#\f "format" format t
     "specify the output format (*unicode*, ascii, latex, or html)")
    (#\s "subexps" subexps nil "include sub-expressions in the output table")
    (#\n "no-vars" no-vars nil "do not include variables in the output table")
    (#\m "multi-char" multi-char nil "allow multi-character variable names")
    (#\i "no-implicit" no-implicit nil "do not use implicit 'and' operations"))
  "Specification for `parse-command-line'. This is of the format:
(short long symbol has-arg-p desc).")

(defun main (argv)
  "The main entry point to the program. ARGV is the list of command line
arguments."
  (let ((cmdline-error nil))
    (handler-bind
        (((or proposition-parse-error proposition-eval-error
              table-format-error)
           (lambda (c)
             (format *error-output* "error: ~a~%" c)
             (uiop:quit 1)))
         (command-line-error
           (lambda (c) ;; finish parsing command line before exiting
             (format *error-output* "error: ~a~%" c)
             (setq cmdline-error t)
             (continue))))
      (destructuring-bind ((&rest prop-strs) &rest opts)
          (parse-command-line *command-line-spec* argv)
        (cond
          ((option-value 'help opts)
           (print-usage t *command-line-spec* "truth-table"
                        :general-args "<propositions...>")
           (uiop:quit (if cmdline-error 1 0)))
          ((null prop-strs)
           (cerror *cli-parse-continue-string* 'no-input-error))
          (cmdline-error
           (format *error-output* "Try -h or --help for more information.~%")
           (uiop:quit 1))
          (t
           (let ((format (option-value 'format opts)))
             (when (or (not format) (zerop (length format)))
               (setq format "unicode"))
             (princ (eval-and-typeset-propositions
                     prop-strs :format format
                               :implicit-and (not (option-value 'no-implicit opts))
                               :multi-char-names (option-value 'multi-char opts)
                               :include-vars (not (option-value 'no-vars opts))
                               :include-intermediate (option-value 'subexps opts)))
             (terpri))))))))

(defun toplevel ()
  "Top-level function to be passed to `save-lisp-and-die'."
  (handler-case
      (with-user-abort:with-user-abort
        (main (uiop:command-line-arguments)))
    (with-user-abort:user-abort ()
      (format *error-output* "Keyboard interrupt~%")
      (uiop:quit 1))))