;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2012, 2013 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Jelle Licht <jlicht@fsfe.org>
;;; Copyright © 2016 David Craven <david@craven.ch>
;;; Copyright © 2017 Ricardo Wurmus <rekado@elephly.net>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix 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 Guix 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 Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (guix import utils)
  #:use-module (guix base32)
  #:use-module ((guix build download) #:prefix build:)
  #:use-module (guix hash)
  #:use-module (guix http-client)
  #:use-module ((guix licenses) #:prefix license:)
  #:use-module (guix utils)
  #:use-module (guix packages)
  #:use-module (guix discovery)
  #:use-module (guix build-system)
  #:use-module (guix gexp)
  #:use-module (guix store)
  #:use-module (guix download)
  #:use-module (gnu packages)
  #:use-module (ice-9 match)
  #:use-module (ice-9 regex)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-11)
  #:export (factorize-uri

            hash-table->alist
            flatten
            assoc-ref*

            url-fetch
            guix-hash-url

            maybe-inputs
            maybe-native-inputs
            package->definition

            spdx-string->license
            license->symbol

            snake-case
            beautify-description

            alist->package))

(define (factorize-uri uri version)
  "Factorize URI, a package tarball URI as a string, such that any occurrences
of the string VERSION is replaced by the symbol 'version."
  (let ((version-rx (make-regexp (regexp-quote version))))
    (match (regexp-exec version-rx uri)
      (#f
       uri)
      (_
       (let ((indices (fold-matches version-rx uri
                                    '((0))
                                    (lambda (m result)
                                      (match result
                                        (((start) rest ...)
                                         `((,(match:end m))
                                           (,start . ,(match:start m))
                                           ,@rest)))))))
         (fold (lambda (index result)
                 (match index
                   ((start)
                    (cons (substring uri start)
                          result))
                   ((start . end)
                    (cons* (substring uri start end)
                           'version
                           result))))
               '()
               indices))))))

(define (hash-table->alist table)
  "Return an alist represenation of TABLE."
  (map (match-lambda
        ((key . (lst ...))
         (cons key
               (map (lambda (x)
                      (if (hash-table? x)
                          (hash-table->alist x)
                          x))
                    lst)))
        ((key . (? hash-table? table))
         (cons key (hash-table->alist table)))
        (pair pair))
       (hash-map->list cons table)))

(define (flatten lst)
  "Return a list that recursively concatenates all sub-lists of LST."
  (fold-right
   (match-lambda*
    (((sub-list ...) memo)
     (append (flatten sub-list) memo))
    ((elem memo)
     (cons elem memo)))
   '() lst))

(define (assoc-ref* alist key . rest)
  "Return the value for KEY from ALIST.  For each additional key specified,
recursively apply the procedure to the sub-list."
  (if (null? rest)
      (assoc-ref alist key)
      (apply assoc-ref* (assoc-ref alist key) rest)))

(define (url-fetch url file-name)
  "Save the contents of URL to FILE-NAME.  Return #f on failure."
  (parameterize ((current-output-port (current-error-port)))
    (build:url-fetch url file-name)))

(define (guix-hash-url filename)
  "Return the hash of FILENAME in nix-base32 format."
  (bytevector->nix-base32-string (file-sha256 filename)))

(define (spdx-string->license str)
  "Convert STR, a SPDX formatted license identifier, to a license object.
   Return #f if STR does not match any known identifiers."
  ;; https://spdx.org/licenses/
  ;; The psfl, gfl1.0, nmap, repoze
  ;; licenses doesn't have SPDX identifiers
  (match str
    ("AGPL-1.0"                    'license:agpl-1.0)
    ("AGPL-3.0"                    'license:agpl-3.0)
    ("Apache-1.1"                  'license:asl1.1)
    ("Apache-2.0"                  'license:asl2.0)
    ("BSL-1.0"                     'license:boost1.0)
    ("BSD-2-Clause-FreeBSD"        'license:bsd-2)
    ("BSD-3-Clause"                'license:bsd-3)
    ("BSD-4-Clause"                'license:bsd-4)
    ("CC0-1.0"                     'license:cc0)
    ("CC-BY-2.0"                   'license:cc-by2.0)
    ("CC-BY-3.0"                   'license:cc-by3.0)
    ("CC-BY-SA-2.0"                'license:cc-by-sa2.0)
    ("CC-BY-SA-3.0"                'license:cc-by-sa3.0)
    ("CC-BY-SA-4.0"                'license:cc-by-sa4.0)
    ("CDDL-1.0"                    'license:cddl1.0)
    ("CECILL-C"                    'license:cecill-c)
    ("Artistic-2.0"                'license:artistic2.0)
    ("ClArtistic"                  'license:clarified-artistic)
    ("CPL-1.0"                     'license:cpl1.0)
    ("EPL-1.0"                     'license:epl1.0)
    ("MIT"                         'license:expat)
    ("FTL"                         'license:freetype)
    ("GFDL-1.1"                    'license:fdl1.1+)
    ("GFDL-1.2"                    'license:fdl1.2+)
    ("GFDL-1.3"                    'license:fdl1.3+)
    ("Giftware"                    'license:giftware)
    ("GPL-1.0"                     'license:gpl1)
    ("GPL-1.0+"                    'license:gpl1+)
    ("GPL-2.0"                     'license:gpl2)
    ("GPL-2.0+"                    'license:gpl2+)
    ("GPL-3.0"                     'license:gpl3)
    ("GPL-3.0+"                    'license:gpl3+)
    ("ISC"                         'license:isc)
    ("IJG"                         'license:ijg)
    ("Imlib2"                      'license:imlib2)
    ("IPA"                         'license:ipa)
    ("IPL-1.0"                     'license:ibmpl1.0)
    ("LGPL-2.0"                    'license:lgpl2.0)
    ("LGPL-2.0+"                   'license:lgpl2.0+)
    ("LGPL-2.1"                    'license:lgpl2.1)
    ("LGPL-2.1+"                   'license:lgpl2.1+)
    ("LGPL-3.0"                    'license:lgpl3.0)
    ("LGPL-3.0+"                   'license:lgpl3.0+)
    ("MPL-1.0"                     'license:mpl1.0)
    ("MPL-1.1"                     'license:mpl1.1)
    ("MPL-2.0"                     'license:mpl2.0)
    ("MS-PL"                       'license:ms-pl)
    ("NCSA"                        'license:ncsa)
    ("OpenSSL"                     'license:openssl)
    ("OLDAP-2.8"                   'license:openldap2.8)
    ("CUA-OPL-1.0"                 'license:opl1.0)
    ("QPL-1.0"                     'license:qpl)
    ("Ruby"                        'license:ruby)
    ("SGI-B-2.0"                   'license:sgifreeb2.0)
    ("OFL-1.1"                     'license:silofl1.1)
    ("Sleepycat"                   'license:sleepycat)
    ("TCL"                         'license:tcl/tk)
    ("Unlicense"                   'license:unlicense)
    ("Vim"                         'license:vim)
    ("X11"                         'license:x11)
    ("ZPL-2.1"                     'license:zpl2.1)
    ("Zlib"                        'license:zlib)
    (_ #f)))

(define (license->symbol license)
  "Convert license to a symbol representing the variable the object is bound
to in the (guix licenses) module, or #f if there is no such known license."
  (define licenses
    (module-map (lambda (sym var) `(,(variable-ref var) . ,sym))
                (resolve-interface '(guix licenses) #:prefix 'license:)))
  (assoc-ref licenses license))

(define (snake-case str)
  "Return a downcased version of the string STR where underscores are replaced
with dashes."
  (string-join (string-split (string-downcase str) #\_) "-"))

(define (beautify-description description)
  "Improve the package DESCRIPTION by turning a beginning sentence fragment
into a proper sentence and by using two spaces between sentences."
  (let ((cleaned (if (string-prefix? "A " description)
                     (string-append "This package provides a"
                                    (substring description 1))
                     description)))
    ;; Use double spacing between sentences
    (regexp-substitute/global #f "\\. \\b"
                              cleaned 'pre ".  " 'post)))

(define* (package-names->package-inputs names #:optional (output #f))
  (map (lambda (input)
         (cons* input (list 'unquote (string->symbol input))
                            (or (and output (list output))
                                '())))
       names))

(define* (maybe-inputs package-names #:optional (output #f))
  "Given a list of PACKAGE-NAMES, tries to generate the 'inputs' field of a
package definition."
  (match (package-names->package-inputs package-names output)
    (()
     '())
    ((package-inputs ...)
     `((inputs (,'quasiquote ,package-inputs))))))

(define* (maybe-native-inputs package-names #:optional (output #f))
  "Given a list of PACKAGE-NAMES, tries to generate the 'inputs' field of a
package definition."
  (match (package-names->package-inputs package-names output)
    (()
     '())
    ((package-inputs ...)
     `((native-inputs (,'quasiquote ,package-inputs))))))

(define (package->definition guix-package)
  (match guix-package
    (('package ('name (? string? name)) _ ...)
     `(define-public ,(string->symbol name)
        ,guix-package))))

(define (build-system-modules)
  (all-modules (map (lambda (entry)
                      `(,entry . "guix/build-system"))
                    %load-path)))

(define (lookup-build-system-by-name name)
  "Return a <build-system> value for the symbol NAME, representing the name of
the build system."
  (fold-module-public-variables (lambda (obj result)
                                  (if (and (build-system? obj)
                                           (eq? name (build-system-name obj)))
                                      obj result))
                                #f
                                (build-system-modules)))

(define (specs->package-lists specs)
  "Convert each string in the SPECS list to a list of a package label and a
package value."
  (map (lambda (spec)
         (let-values (((pkg out) (specification->package+output spec)))
           (match out
             (("out") (list (package-name pkg) pkg))
             (_ (list (package-name pkg) pkg out)))))
       specs))

(define (source-spec->object source)
  "Generate an <origin> object from a SOURCE specification.  The SOURCE can
either be a simple URL string, #F, or an alist containing entries for each of
the expected fields of an <origin> object."
  (match source
    ((? string? source-url)
     (let ((tarball (with-store store (download-to-store store source-url))))
       (origin
         (method url-fetch)
         (uri source-url)
         (sha256 (base32 (guix-hash-url tarball))))))
    (#f #f)
    (orig (let ((sha (match (assoc-ref orig "sha256")
                       ((("base32" . value))
                        (base32 value))
                       (_ #f))))
            (origin
              (method (match (assoc-ref orig "method")
                        ("url-fetch" (@ (guix download) url-fetch))
                        ("git-fetch" (@ (guix git-download) git-fetch))
                        ("svn-fetch" (@ (guix svn-download) svn-fetch))
                        ("hg-fetch"  (@ (guix hg-download) hg-fetch))
                        (_ #f)))
              (uri (assoc-ref orig "uri"))
              (sha256 sha))))))

(define (alist->package meta)
  (package
    (name (assoc-ref meta "name"))
    (version (assoc-ref meta "version"))
    (source (source-spec->object (assoc-ref meta "source")))
    (build-system
      (lookup-build-system-by-name
       (string->symbol (assoc-ref meta "build-system"))))
    (native-inputs
     (specs->package-lists (or (assoc-ref meta "native-inputs") '())))
    (inputs
     (specs->package-lists (or (assoc-ref meta "inputs") '())))
    (propagated-inputs
     (specs->package-lists (or (assoc-ref meta "propagated-inputs") '())))
    (home-page
     (assoc-ref meta "home-page"))
    (synopsis
     (assoc-ref meta "synopsis"))
    (description
     (assoc-ref meta "description"))
    (license
     (let ((l (assoc-ref meta "license")))
       (or (module-ref (resolve-interface '(guix licenses) #:prefix 'license:)
                       (spdx-string->license l))
           (license:fsdg-compatible l))))))
