;; -*-scheme-*-
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; 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 2 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, contact:
;;
;; Free Software Foundation           Voice:  +1-617-542-5942
;; 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652
;; Boston, MA  02110-1301,  USA       gnu@gnu.org
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


;; This is a sample guile report generator for GnuCash.
;; It illustrates the basic techniques used to create
;; new reports for GnuCash.

(define-module (gnucash report my-piecash-report-simple))
(use-modules (gnucash main)) ;; FIXME: delete after we finish modularizing.
(use-modules (gnucash gnc-module))
(use-modules (gnucash gettext))
(use-modules (gnucash core-utils))

;; 'debug is deprecated and unused since guile 2
(cond-expand
  (guile-2 )
  (else
    (debug-enable 'debug)))
(debug-enable 'backtrace)

(gnc:module-load "gnucash/report/report-system" 0)
(gnc:module-load "gnucash/html" 0) ;for gnc-build-url

;; This function will generate a set of options that GnuCash
;; will use to display a dialog where the user can select
;; values for your report's parameters.
(define (options-generator)    
  (let* ((options (gnc:new-options)) 
         ;; This is just a helper function for making options.
         ;; See gnucash/src/app-utils/options.scm for details.
         (add-option 
          (lambda (new-option)
            (gnc:register-option options new-option))))
    

    ;; This is a number range option. The user can enter a number
    ;; between a lower and upper bound given below. There are also
    ;; arrows the user can click to go up or down, the amount changed
    ;; by a single click is given by the step size.
    (add-option
     (gnc:make-number-range-option
      (N_ "Hello, World!") (N_ "Number Option")
      "ee" (N_ "This is a number option.")
      1500.0  ;; default
      0.0     ;; lower bound
      10000.0 ;; upper bound
      2.0     ;; number of decimals
      0.01    ;; step size
      ))

    (gnc:options-set-default-section options "Hello, World!")      
    options))

;; This is the rendering function. It accepts a database of options.
(define (python-renderer report-obj)
  ;; These are some helper functions for looking up option values.
  (define (get-op section name)
    (gnc:lookup-option (gnc:report-options report-obj) section name))
  (define (op-value section name)
    (gnc:option-value (get-op section name)))

  ;; call the python script
  ;; TODO: find a way to pipe the option to the python script (as yaml/json ?)
  ;; TODO: find a way send the URI of the book to the python script
  (let ((num-val      (op-value "Hello, World!" "Number Option"))
        )
      (gnc:run-outside-program "simple_report.py")
  )
)

(define (gnc:run-outside-program py-script)
  (let ((program '())
        (from-child #f))

    (define (start-program)
      (set! program (gnc-spawn-process-async
                     (list "python" (gnc-build-dotgnucash-path py-script))
                     #t)))

    (define (read-port port)
        (let iter ((result '()) (chr (read-char port)))
            (if (eof-object? chr)
                (list->string result)
                (iter (append result (list chr)) (read-char port)))))

    (define (get-sources)

          (let ((results #f))
            (set! from-child (fdes->inport (gnc-process-get-fd program 1)))
            (catch
             #t
             (lambda ()
               (set! results (read-port from-child))
               results)
             (lambda (key . args)
               key))))

    (define (kill-program)
      (if (not (null? program))
          (gnc-detach-process program #t)))

    (dynamic-wind
        start-program
        get-sources
        kill-program)))


;; Here we define the actual report with gnc:define-report
(gnc:define-report
 
 ;; The version of this report.
 'version 1
 
 ;; The name of this report. This will be used, among other things,
 ;; for making its menu item in the main menu. You need to use the
 ;; untranslated value here!
 'name (N_ "Piecash simple report")

 ;; The GUID for this report. This string should be unique, set once
 ;; and left alone forever after that. In theory, you could use any
 ;; unique string, even a meaningful one (!) but its probably best to
 ;; use a true uuid. Get them from `uuidgen | sed -e s/-//g` and paste
 ;; the results in here. You must make a new guid for each report!
 'report-guid "222d78ec92854403bf76e20a36d24ccc"

 ;; The name in the menu
 ;; (only necessary if it differs from the name)
 ;; 'menu-name (N_ "Sample Report with Examples")

 ;; A tip that is used to provide additional information about the
 ;; report to the user.
 'menu-tip (N_ "A simple test for a piecash report.")

 ;; A path describing where to put the report in the menu system.
 ;; In this case, it's going under the utility menu.
 'menu-path (list gnc:menuname-utility)

 ;; The options generator function defined above.
 'options-generator options-generator
 
 ;; The rendering function defined above.
 'renderer python-renderer)