;;;; Copyright (C) 2019, 2020 Julien Lepiller <julien@lepiller.eu>

;;;; 

;;;; This library is free software; you can redistribute it and/or

;;;; modify it under the terms of the GNU Lesser General Public

;;;; License as published by the Free Software Foundation; either

;;;; version 3 of the License, or (at your option) any later version.

;;;; 

;;;; This library 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

;;;; Lesser General Public License for more details.

;;;; 

;;;; You should have received a copy of the GNU Lesser General Public

;;;; License along with this library; if not, write to the Free Software

;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

;;;; 

(define-module (jsonld context)

  #:use-module (ice-9 match)

  #:use-module (jsonld json)

  #:use-module (srfi srfi-9)

  #:export (make-active-context

            active-context?

            active-context-definitions

            active-context-base

            active-context-original-base

            active-context-vocab

            active-context-language

            active-context-direction

            active-context-previous

            new-active-context

            update-active-context

            make-term-definition

            term-definition?

            term-definition-iri

            term-definition-base-url

            term-definition-reverse?

            term-definition-type

            term-definition-language

            term-definition-direction

            term-definition-context

            term-definition-nest

            term-definition-prefix?

            term-definition-index

            term-definition-protected?

            term-definition-container

            term-definition-equal?

            new-term-definition

            update-term-definition

            term-definition-ref))

;;; Section 4.1: definitions of an Active Context and a Term Definition

(define-record-type active-context

  (make-active-context definitions base original-base vocab language direction

                       previous)

  active-context?

  (definitions   active-context-definitions)

  (base          active-context-base)

  (original-base active-context-original-base)

  (vocab         active-context-vocab)

  (language      active-context-language)

  (direction     active-context-direction)

  (previous      active-context-previous))

(define* (update-active-context

           active-context

           #:key (definitions   (active-context-definitions   active-context))

                 (base          (active-context-base          active-context))

                 (original-base (active-context-original-base active-context))

                 (vocab         (active-context-vocab         active-context))

                 (language      (active-context-language      active-context))

                 (direction     (active-context-direction     active-context))

                 (previous      (active-context-previous      active-context)))

  (make-active-context definitions base original-base vocab language direction

                       previous))

(define* (new-active-context

           #:key (definitions   '())

                 (base          #f)

                 (original-base #f)

                 (vocab         #f)

                 (language      #f)

                 (direction     #f)

                 (previous      json-null))

  (make-active-context definitions base original-base vocab language direction

                       previous))

(define-record-type term-definition

  (make-term-definition iri prefix? protected? reverse? base-url context container

                        direction index language nest type)

  term-definition?

  (iri        term-definition-iri)

  (prefix?    term-definition-prefix?)

  (protected? term-definition-protected?)

  (reverse?   term-definition-reverse?)

  (base-url   term-definition-base-url)

  (context    term-definition-context)

  (container  term-definition-container)

  (direction  term-definition-direction)

  (index      term-definition-index)

  (language   term-definition-language)

  (nest       term-definition-nest)

  (type       term-definition-type))

(define* (update-term-definition

           term-definition

           #:key (iri        (term-definition-iri        term-definition))

                 (prefix?    (term-definition-prefix?    term-definition))

                 (protected? (term-definition-protected? term-definition))

                 (reverse?   (term-definition-reverse?   term-definition))

                 (base-url   (term-definition-base-url   term-definition))

                 (context    (term-definition-context    term-definition))

                 (container  (term-definition-container  term-definition))

                 (direction  (term-definition-direction  term-definition))

                 (index      (term-definition-index      term-definition))

                 (language   (term-definition-language   term-definition))

                 (nest       (term-definition-nest       term-definition))

                 (type       (term-definition-type       term-definition)))

  (make-term-definition iri prefix? protected? reverse? base-url context container

                        direction index language nest type))

(define* (new-term-definition

           #:key (iri        #f)

                 (prefix?    #f)

                 (protected? #f)

                 (reverse?   #f)

                 (base-url   #f)

                 (context    #f)

                 (container  #f)

                 (direction  #f)

                 (index      #f)

                 (language   #f)

                 (nest       #f)

                 (type       #f))

  (make-term-definition iri prefix? protected? reverse? base-url context container

                        direction index language nest type))

(define (term-definition-equal? a b)

  (match a

    (($ term-definition iri prefix? protected? reverse? base-url context

        container direction index language nest type)

     (and (term-definition? b)

          (equal? iri        (term-definition-iri        b))

          (equal? prefix?    (term-definition-prefix?    b))

          (equal? protected? (term-definition-protected? b))

          (equal? reverse?   (term-definition-reverse?   b))

          (equal? base-url   (term-definition-base-url   b))

          (equal? context    (term-definition-context    b))

          (equal? container  (term-definition-container  b))

          (equal? direction  (term-definition-direction  b))

          (equal? index      (term-definition-index      b))

          (equal? language   (term-definition-language   b))

          (equal? nest       (term-definition-nest       b))

          (equal? type       (term-definition-type       b))))

    (_ #f)))

(define (term-definition-ref context term)

  (let ((definitions (active-context-definitions context)))

    (assoc-ref definitions term)))