;;; em-script.el --- Eshell script files  -*- lexical-binding:t -*-

;; Copyright (C) 1999-2024 Free Software Foundation, Inc.

;; Author: John Wiegley <johnw@gnu.org>

;; This file is part of GNU Emacs.

;; GNU Emacs 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.

;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;;; Code:

(require 'esh-mode)
(require 'esh-io)

;;;###esh-module-autoload
(progn
(defgroup eshell-script nil
  "This module allows for the execution of files containing Eshell
commands, as a script file."
  :tag "Running script files."
  :group 'eshell-module))

;;; User Variables:

(defcustom eshell-script-load-hook nil
  "A list of functions to call when loading `eshell-script'."
  :version "24.1"                       ; removed eshell-script-initialize
  :type 'hook
  :group 'eshell-script)

(defcustom eshell-login-script (expand-file-name "login" eshell-directory-name)
  "If non-nil, a file to invoke when starting up Eshell interactively.
This file should be a file containing Eshell commands, where comment
lines begin with `#'."
  :type 'file
  :group 'eshell-script)

(defcustom eshell-rc-script (expand-file-name "profile" eshell-directory-name)
  "If non-nil, a file to invoke whenever Eshell is started.
This includes when running `eshell-command'."
  :type 'file
  :group 'eshell-script)

;;; Functions:

(defun eshell-script-initialize ()  ;Called from `eshell-mode' via intern-soft!
  "Initialize the script parsing code."
  (setq-local eshell-interpreter-alist
              (cons (cons (lambda (file _args)
                            (and (file-regular-p file)
                                 (string= (file-name-nondirectory file)
                                          "eshell")))
                          'eshell/source)
                    eshell-interpreter-alist))
  (setq-local eshell-complex-commands
	(append '("source" ".") eshell-complex-commands))
  ;; these two variables are changed through usage, but we don't want
  ;; to ruin it for other modules
  (let (eshell-inside-quote-regexp
	eshell-outside-quote-regexp)
    (and (not (bound-and-true-p eshell-non-interactive-p))
	 eshell-login-script
	 (file-readable-p eshell-login-script)
	 (eshell-do-eval
	  `(eshell-commands ,(eshell--source-file eshell-login-script))
          t))
    (and eshell-rc-script
	 (file-readable-p eshell-rc-script)
	 (eshell-do-eval
	  `(eshell-commands ,(eshell--source-file eshell-rc-script))
          t))))

(defun eshell--source-file (file &optional args subcommand-p)
  "Return a Lisp form for executig the Eshell commands in FILE, passing ARGS.
If SUBCOMMAND-P is non-nil, execute this as a subcommand."
  (let ((cmd (eshell-parse-command `(:file . ,file))))
    (when subcommand-p
      (setq cmd `(eshell-as-subcommand ,cmd)))
    `(let ((eshell-command-name ',file)
           (eshell-command-arguments ',args)
           ;; Don't print subjob messages by default.  Otherwise, if
           ;; this function was called as a subjob, then *all* commands
           ;; in the script would print start/stop messages.
           (eshell-subjob-messages nil))
       ,cmd)))

(defun eshell-source-file (file &optional args subcommand-p)
  "Execute a series of Eshell commands in FILE, passing ARGS.
Comments begin with `#'."
  (declare (obsolete nil "30.1"))
  (throw 'eshell-replace-command
         (eshell--source-file file args subcommand-p)))

;;;###autoload
(defun eshell-execute-file (file &optional args destination)
  "Execute a series of Eshell commands in FILE, passing ARGS.
Comments begin with `#'."
  (let ((eshell-non-interactive-p t)
        (stdout (if (eq destination t) (current-buffer) destination)))
    (with-temp-buffer
      (eshell-mode)
      (eshell-do-eval
       `(let ((eshell-current-handles
               (eshell-create-handles ,stdout 'insert))
              (eshell-current-subjob-p))
          ,(eshell--source-file file args))
       t))))

(cl-defstruct (eshell-princ-target
               (:include eshell-generic-target)
               (:constructor nil)
               (:constructor eshell-princ-target-create
                             (&optional printcharfun)))
  "A virtual target calling `princ' (see `eshell-virtual-targets')."
  printcharfun)

(cl-defmethod eshell-output-object-to-target (object
                                              (target eshell-princ-target))
  "Output OBJECT to the `princ' function TARGET."
  (princ object (eshell-princ-target-printcharfun target)))

(cl-defmethod eshell-target-line-oriented-p ((_target eshell-princ-target))
  "Return non-nil to indicate that the display is line-oriented."
  t)

;;;###autoload
(defun eshell-batch-file ()
  "Execute an Eshell script as a batch script from the command line.
Inside your Eshell script file, you can add the following at the
top in order to make it into an executable script:

  #!/usr/bin/env -S emacs --batch -f eshell-batch-file"
  (let ((file (pop command-line-args-left))
        (args command-line-args-left)
        (eshell-non-interactive-p t)
        (eshell-module-loading-messages nil)
        (eshell-virtual-targets
         (append `(("/dev/stdout" ,(eshell-princ-target-create) nil)
                   ("/dev/stderr" ,(eshell-princ-target-create
                                    #'external-debugging-output)
                   nil))
                 eshell-virtual-targets)))
    (setq command-line-args-left nil)
    (with-temp-buffer
      (eshell-mode)
      (eshell-do-eval
       `(let ((eshell-current-handles
               (eshell-create-handles "/dev/stdout" 'append
                                      "/dev/stderr" 'append))
              (eshell-current-subjob-p))
          ,(eshell--source-file file args))
       t))))

(defun eshell/source (file &rest args)
  "Source a FILE in a subshell environment."
  (throw 'eshell-replace-command
         (eshell--source-file file args t)))

(put 'eshell/source 'eshell-no-numeric-conversions t)

(defun eshell/. (file &rest args)
  "Source a FILE in the current environment."
  (throw 'eshell-replace-command
         (eshell--source-file file args)))

(put 'eshell/. 'eshell-no-numeric-conversions t)

(provide 'em-script)
;;; em-script.el ends here