#! /usr/bin/env guile
!#
;;; ccwl --- Concise Common Workflow Language
;;; Copyright © 2021, 2022 Arun Isaac <arunisaac@systemreboot.net>
;;;
;;; This file is part of ccwl.
;;;
;;; ccwl 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.
;;;
;;; ccwl 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 ccwl.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; This script is the command-line interface to ccwl.

;;; Code:

(use-modules (srfi srfi-28)
             (srfi srfi-37)
             (ice-9 match)
             (ccwl ccwl)
             (ccwl cwl)
             (ccwl graphviz))

(define (invalid-option opt name arg result)
  (error "Invalid option" name))

(define (invalid-operand arg result)
  (error "Invalid argument" arg))

(define %help-option
  (option (list "help") #f #t
          (lambda (opt name arg result)
            (acons 'help #t result))))

(define main
  (match-lambda*
    ((program "compile" args ...)
     (let* ((args (args-fold args
                             (list (option (list #\t "to") #t #f
                                           (lambda (opt name arg result)
                                             (let ((supported (list "cwl" "dot")))
                                               (unless (member arg supported)
                                                 (scm-error 'misc-error
                                                            #f
                                                            "Invalid target ~A argument ~S. Supported targets are ~A."
                                                            (list (if (char? name)
                                                                      (string #\- name)
                                                                      (string-append "--" name))
                                                                  arg
                                                                  (string-join supported ", "))
                                                            #f)))
                                             (acons 'to arg result)))
                                   %help-option)
                             invalid-option
                             (lambda (arg result)
                               (acons 'source-file arg result))
                             '((to . "cwl")))))
       (when (or (assq 'help args)
                 (not (assq-ref args 'source-file)))
         (display (format "Usage: ~a compile [OPTIONS] SOURCE-FILE
Compile SOURCE-FILE.

  -t, --to=TARGET    compile SOURCE-FILE to TARGET language;
                     Supported targets are cwl (default) and dot.

"
                          program)
                  (current-error-port))
         (exit (assq 'help args)))
       ;; FIXME: Compiling ccwl files fails since the workflow macro is
       ;; unable to access command definitions.
       (set! %load-should-auto-compile #f)
       (let ((to (assq-ref args 'to)))
         ((cond
           ((string=? to "cwl") workflow->cwl)
           ((string=? to "dot") workflow->dot))
          (load (canonicalize-path (assq-ref args 'source-file))
                read-syntax)
          (current-output-port)))))
    ((program args ...)
     (let ((args (args-fold args
                            (list %help-option)
                            (lambda (opt name arg result)
                              result)
                            (lambda (arg result)
                              result)
                            '())))
       (display (format "Usage: ~a COMMAND [OPTIONS] [ARGS]

COMMAND must be one of the sub-commands listed below:

  compile   compile a workflow

To get usage information for one of these sub-commands, run
  ~a COMMAND --help

"
                        program program)
                (current-error-port))
       (exit (assq 'help args))))))

(apply main (command-line))