;;; ob-sh.el --- org-babel functions for shell evaluation

;; Copyright (C) 2009, 2010  Free Software Foundation, Inc.

;; Author: Eric Schulte
;; Keywords: literate programming, reproducible research
;; Homepage: http://orgmode.org
;; Version: 0.01

;; 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 <http://www.gnu.org/licenses/>.

;;; Commentary:

;; Org-Babel support for evaluating shell source code.

;;; Code:
(require 'ob)
(require 'ob-comint)
(require 'ob-eval)
(require 'shell)
(eval-when-compile (require 'cl))

(declare-function org-babel-ref-variables "ob-ref" (params))
(declare-function org-babel-comint-in-buffer "ob-comint" (buffer &rest body))
(declare-function org-babel-comint-wait-for-output "ob-comint" (buffer))
(declare-function org-babel-comint-buffer-livep "ob-comint" (buffer))
(declare-function org-babel-comint-with-output "ob-comint" (meta &rest body))
(declare-function orgtbl-to-generic "org-table" (table params))

(defvar org-babel-default-header-args:sh '())

(defvar org-babel-sh-command "sh"
  "Command used to invoke a shell.
This will be passed to  `shell-command-on-region'")

(defun org-babel-expand-body:sh (body params &optional processed-params)
  "Expand BODY according to PARAMS, return the expanded body."
  (let ((vars (nth 1 (or processed-params (org-babel-process-params params))))
        (sep (cdr (assoc :separator params))))
    (concat
   (mapconcat ;; define any variables
    (lambda (pair)
      (format "%s=%s"
              (car pair)
              (org-babel-sh-var-to-sh (cdr pair) sep)))
    vars "\n") "\n" body "\n\n")))

(defun org-babel-execute:sh (body params)
  "Execute a block of Shell commands with Babel.
This function is called by `org-babel-execute-src-block'."
  (let* ((processed-params (org-babel-process-params params))
         (session (org-babel-sh-initiate-session (nth 0 processed-params)))
         (result-params (nth 2 processed-params)) 
         (full-body (org-babel-expand-body:sh
                     body params processed-params)))
    (org-babel-reassemble-table
     (org-babel-sh-evaluate session full-body result-params)
     (org-babel-pick-name
      (nth 4 processed-params) (cdr (assoc :colnames params)))
     (org-babel-pick-name
      (nth 5 processed-params) (cdr (assoc :rownames params))))))

(defun org-babel-prep-session:sh (session params)
  "Prepare SESSION according to the header arguments specified in PARAMS."
  (let* ((session (org-babel-sh-initiate-session session))
         (vars (org-babel-ref-variables params))
         (sep (cdr (assoc :separator params)))
         (var-lines (mapcar ;; define any variables
                     (lambda (pair)
                       (format "%s=%s"
                               (car pair)
                               (org-babel-sh-var-to-sh (cdr pair) sep)))
                     vars)))
    (org-babel-comint-in-buffer session
      (mapc (lambda (var)
              (insert var) (comint-send-input nil t)
              (org-babel-comint-wait-for-output session)) var-lines))
    session))

(defun org-babel-load-session:sh (session body params)
  "Load BODY into SESSION."
  (save-window-excursion
    (let ((buffer (org-babel-prep-session:sh session params)))
      (with-current-buffer buffer
        (goto-char (process-mark (get-buffer-process (current-buffer))))
        (insert (org-babel-chomp body)))
      buffer)))

;; helper functions

(defun org-babel-sh-var-to-sh (var &optional sep)
  "Convert an elisp value to a shell variable.
Convert an elisp var into a string of shell commands specifying a
var of the same value."
  (if (listp var)
      (flet ((deep-string (el)
                          (if (listp el)
                              (mapcar #'deep-string el)
			    (org-babel-sh-var-to-sh el sep))))
	(format "$(cat <<BABEL_TABLE\n%s\nBABEL_TABLE\n)"
		(orgtbl-to-generic
		 (deep-string var) (list :sep (or sep "\t")))))
    (if (stringp var)
	(if (string-match "[\n\r]" var)
	    (format "$(cat <<BABEL_STRING\n%s\nBABEL_STRING\n)" var)
	  (format "%s" var))
      (format "%S" var))))

(defun org-babel-sh-table-or-results (results)
  "Convert RESULTS to an appropriate elisp value.
If the results look like a table, then convert them into an
Emacs-lisp table, otherwise return the results as a string."
  (org-babel-read
   (if (string-match "^\\[.+\\]$" results)
       (org-babel-read
        (concat "'"
                (replace-regexp-in-string
                 "\\[" "(" (replace-regexp-in-string
                            "\\]" ")" (replace-regexp-in-string
                                       ", " " " (replace-regexp-in-string
                                                 "'" "\"" results))))))
     results)))

(defun org-babel-sh-initiate-session (&optional session params)
  "Initiate a session named SESSION according to PARAMS."
  (when (and session (not (string= session "none")))
    (save-window-excursion
      (or (org-babel-comint-buffer-livep session)
          (progn (shell session) (get-buffer (current-buffer)))))))

(defvar org-babel-sh-eoe-indicator "echo 'org_babel_sh_eoe'"
  "String to indicate that evaluation has completed.")
(defvar org-babel-sh-eoe-output "org_babel_sh_eoe"
  "String to indicate that evaluation has completed.")

(defun org-babel-sh-evaluate (session body &optional result-params)
  "Pass BODY to the Shell process in BUFFER.
If RESULT-TYPE equals 'output then return a list of the outputs
of the statements in BODY, if RESULT-TYPE equals 'value then
return the value of the last statement in BODY."
  ((lambda (results)
     (if (or (member "scalar" result-params)
	     (member "output" result-params))
	 results
       (let ((tmp-file (make-temp-file "org-babel-sh")))
	 (with-temp-file tmp-file (insert results))
	 (org-babel-import-elisp-from-file tmp-file))))
   (if (not session)
       (org-babel-eval org-babel-sh-command (org-babel-trim body))
     (let ((tmp-file (make-temp-file "org-babel-sh")))
       (mapconcat
	#'org-babel-sh-strip-weird-long-prompt
	(mapcar
	 #'org-babel-trim
	 (butlast
	  (org-babel-comint-with-output
	      (session org-babel-sh-eoe-output t body)
	    (mapc
	     (lambda (line)
	       (insert line) (comint-send-input nil t) (sleep-for 0.25))
	     (append
	      (split-string (org-babel-trim body) "\n")
	      (list org-babel-sh-eoe-indicator))))
	  2)) "\n")))))

(defun org-babel-sh-strip-weird-long-prompt (string)
  "Remove prompt cruft from a string of shell output."
  (while (string-match "^% +[\r\n$]+ *" string)
    (setq string (substring string (match-end 0))))
  string)

(provide 'ob-sh)

;; arch-tag: 416dd531-c230-4b0a-a5bf-8d948f990f2d

;;; ob-sh.el ends here