01/07: Add 'guix git log'.

[guix-commits]

magali pushed a commit to branch wip-guix-log
in repository guix.

commit 4cceeb52bfe4624221d5ac84cf49e82e5dd461e6
Author: Magali Lemes <magalilemes00@gmail.com>
AuthorDate: Thu Dec 3 10:56:03 2020 -0300

    Add 'guix git log'.
    
    * guix/scripts/git/log.scm: New file.
    * guix/scripts/git.scm (%sub-commands): Add "log".
---
 guix/scripts/git.scm     |  2 +-
 guix/scripts/git/log.scm | 98 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 99 insertions(+), 1 deletion(-)

diff --git a/guix/scripts/git.scm b/guix/scripts/git.scm
index 4436d8a..8fcd0cc 100644
--- a/guix/scripts/git.scm
+++ b/guix/scripts/git.scm
@@ -38,7 +38,7 @@ Operate on Git repositories.\n"))
   (newline)
   (show-bug-report-information))
 
-(define %sub-commands '("authenticate"))
+(define %sub-commands '("authenticate" "log"))
 
 (define (resolve-sub-command name)
   (let ((module (resolve-interface
diff --git a/guix/scripts/git/log.scm b/guix/scripts/git/log.scm
new file mode 100644
index 0000000..63f1913
--- /dev/null
+++ b/guix/scripts/git/log.scm
@@ -0,0 +1,98 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2020 Magali Lemes <magalilemes00@gmail.com>
+;;;
+;;; 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 scripts git log)
+  #:use-module (git)
+  #:use-module ((guix channels)
+                #:select (%default-guix-channel
+                          channel-url))
+  #:use-module ((guix git) #:select (url-cache-directory))
+  #:use-module (guix scripts)
+  #:use-module (guix ui)
+  #:use-module (ice-9 format)
+  #:use-module (ice-9 match)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-26)
+  #:use-module (srfi srfi-37)
+  #:export (guix-git-log))
+
+
+(define %options
+  (list (option '(#\h "help") #f #f
+                (lambda args
+                  (show-help)
+                  (exit 0)))
+
+        (option '("checkout-path") #f #f
+                (lambda (opt name arg result)
+                  (alist-cons 'checkout-path? #t result)))
+        (option '("oneline") #f #f
+                (lambda (opt name arg result)
+                  (alist-cons 'oneline? #t result)))))
+
+(define %default-options
+  '())
+
+(define (show-help)
+  (display (G_ "Usage: guix git log [OPTIONS...]
+Show Guix commit logs.\n"))
+  (display (G_ "
+      --checkout-path    show checkout path"))
+  (display (G_ "
+      --oneline          show short hash and summary of five first commits"))
+  (display (G_ "
+  -h, --help             display this help and exit"))
+  (newline)
+  (show-bug-report-information))
+
+(define (show-checkout-path)
+  (display (url-cache-directory (channel-url %default-guix-channel)))
+  (newline))
+
+(define commit-short-id
+  (compose (cut string-take <> 7) oid->string commit-id))
+
+(define (show-commit commit)
+    (format #t (G_ "~a ~a~%") (commit-short-id commit) (commit-summary 
commit)))
+
+;; currently showing 5 latest commits
+(define (get-commits path)
+  (let* ((repository (repository-open path))
+         (latest-commit (commit-lookup repository (reference-target 
(repository-head repository)))))
+    (for-each show-commit (take
+                           (let loop ((commit latest-commit)
+                                      (res (list latest-commit)))
+                             (match (commit-parents commit)
+                                    (() (reverse res))
+                                    ((head . tail)
+                                     (loop head (cons head res)))))
+                           5))))
+
+(define (guix-git-log . args)
+  (define options
+    (parse-command-line args %options (list %default-options)))
+
+  (let ((checkout-path? (assoc-ref options 'checkout-path?))
+        (oneline?       (assoc-ref options 'oneline?)))
+    (with-error-handling
+      (cond
+       (checkout-path?
+        (show-checkout-path))
+       (oneline?
+        (let ((cache (url-cache-directory (channel-url 
%default-guix-channel))))
+          (get-commits cache)))))))