#:use-module (gnu packages bash)

  #:use-module (guix build-system trivial)

;; Python wrapped with jemalloc enabled
;; (needed by pxr.Usdviewq Python module)
(define python-for-usd
  (package
   (inherit python-3.9)
   (inputs (modify-inputs (package-inputs python-3.9)
			    (prepend jemalloc-5.3)))
   (arguments
     (substitute-keyword-arguments (package-arguments python-3.9)
       ((#:phases phases)
         `(modify-phases ,phases
	  (add-after 'install 'use-jemalloc
	    (lambda* (#:key inputs outputs #:allow-other-keys)
              (wrap-program (string-append (assoc-ref outputs "out")
			    "/bin/python3.9")
                `("LD_PRELOAD" =
                  (,(search-input-file
                    inputs "/lib/libjemalloc.so.2"))))))))))))
(define* (wrap-python3 python
                       #:optional
                       (name (string-append (package-name python) "-wrapper")))
  (package/inherit python
    (name name)
    (source #f)
    (build-system trivial-build-system)
    (outputs '("out"))
    (inputs `(("bash" ,bash)))
    (propagated-inputs `(("python" ,python)))
    (arguments
     `(#:modules ((guix build utils))
       #:builder
         (begin
           (use-modules (guix build utils))
           (let ((bin (string-append (assoc-ref %outputs "out") "/bin"))
                 (python (string-append (assoc-ref %build-inputs "python") "/bin/")))
                (mkdir-p bin)
                (for-each
                  (lambda (old new)
                    (symlink (string-append python old)
                             (string-append bin "/" new)))
                  `("python3" ,"pydoc3" ,"pip3")
                  `("python"  ,"pydoc"  ,"pip"))
                ;; python-config outputs search paths based upon its location,
                ;; use a bash wrapper to avoid changing its outputs.
                (let ((bash (string-append (assoc-ref %build-inputs "bash")
                                           "/bin/bash"))
                      (old  (string-append python "python3-config"))
                      (new  (string-append bin "/python-config")))
                  (with-output-to-file new
                    (lambda ()
                      (format #t "#!~a~%" bash)
                      (format #t "exec \"~a\" \"$@\"~%" old)
                      (chmod new #o755))))))))
    (synopsis "Wrapper for the Python 3 commands")
    (description
     "This package provides wrappers for the commands of Python@tie{}3.x such
that they can also be invoked under their usual names---e.g., @command{python}
instead of @command{python3} or @command{pip} instead of @command{pip3}.
To function properly, this package should not be installed together with the
@code{python} package: this package uses the @code{python} package as a
propagated input, so installing this package already makes both the versioned
and the unversioned commands available.")))
;; "python" link pointing to "python3" command
(define-public python-wrapper-for-usd (wrap-python3 python-for-usd))

	       ;; TODO: Fix jemalloc support for USD
               ;; so far causing segfault when Python import pxr.Usdviewq

               #t)))))

		 #t))
           (add-after 'install 'fix-installed-python-modules-path
		      (lambda* (#:key outputs #:allow-other-keys)
			       (let* ((now (string-append (assoc-ref outputs "out")
							  "/lib/python"))
				      (dir (string-append now
							  ,(version-major+minor
						            (package-version python-wrapper-for-usd))))
				      (fix (string-append dir
							  "/site-packages")))
				 (mkdir-p dir)
				 (rename-file now fix)))))))

       python

       python-wrapper-for-usd