;;; ein-cell-output.el --- Cell module

;; (C) 2015- John M. Miller

;; Author: John M. Miller (millejoh at mac dot com)

;; This file is NOT part of GNU Emacs.

;; ein-cell-output.el 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.

;; ein-cell-output.el 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 ein-cell-output.el.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;  Because wiriting cell outputs to nbformat v4.0 json is complicated
;;  enought that it warrants a file all to its own.

;;; Code:

(require 'ein-cell)

(defvar ein:output-type-map
  '((:svg . :image/svg+xml) (:png . :image/png) (:jpeg . :image/jpeg)
    (:text . :text/plain)
    (:html . :text/html) (:latex . :text/latex) (:javascript . :text/javascript)))

(defun ein:output-property (maybe-property)
  (cdr (assoc maybe-property ein:output-type-map)))

;;; Dealing with Code cell outputs
(defun ein:cell-stream-output-to-json (output)
  `((output_type . "stream")
    (name . ,(plist-get output :stream))
    (text . ,(plist-get output :text))))

(defun ein:cell-error-output-to-json (output)
  `((output_type . "error")
    (ename . ,(plist-get output :ename))
    (evalue . ,(plist-get output :evalue))
    (traceback . ,(plist-get output :traceback))))

(defun ein:cell-execute-result-output-to-json (output)
  (let ((data (ein:aif (plist-get output :text)
		  `("text/plain" . ,it)
		(plist-get output :data))))
    `((output_type . "execute_result")
      (metadata . ,(make-hash-table))
      (execution_count . ,(or (plist-get output :prompt_number)
			      (plist-get output :execution_count)))
      (data . (,data)))))

(defun ein:maybe-get-output-mime-data (output)
  (cl-loop for type in '(:svg :png :jpeg :html :latex  :javascript :text)
    if (plist-get output type)
    collecting (cons (ein:output-property type) (plist-get output type))))

(defun ein:cell-display-data-output-to-json (output)
  (let ((data (or (ein:maybe-get-output-mime-data output)
                  (plist-get output :data))))
    `((output_type . "display_data")
      (data . ,data)
      (metadata . ,(make-hash-table)))))

(defun ein:find-and-make-outputs (output-plist)
  (cl-loop for prop in ein:output-type-map
    when (plist-get output-plist (cdr prop))
    collect (list (cdr prop) (plist-get output-plist (cdr prop)))))

(provide 'ein-cell-output)