Archiver script improvements.

Relating to #235.

* Rolled back to using deflate for zip files, as some Windows versions
don't support LZMA, which could confuse users into thinking the archive
is broken.
* Added support for using 7-zip if it is installed.
* Added archive filename versioning using `git describe --tags --long`
if git.exe is found in the PATH or in a GitHub for Windows install.

src/archive.py

@@ -30,21 +30,65 @@ import sys
 import os
 import shutil
 import zipfile
+import subprocess
 
 temp_path = os.path.join('..', 'build', 'archive.tmp')
 archive_name = 'LOOT Archive.zip'
 
-# Set archive name if alternative is given.
-if (len(sys.argv) > 1):
-    archive_name = sys.argv[1]
+# Some initial setup.
+#
+# There are two compression methods available:
+#
+#  * Zip (Deflate)
+#  * 7-zip (LZMA)
+#
+# Python 3.3+ can also do BZIP2 and LZMA zip archives, but they don't have good
+# Windows OS support, so people think they should be able to open them without
+# an archiving utility, find they can't, and think the archive is broken. So
+# they won't be used.
+#
+# Look for 7-zip in its default install location, and use it if it is found.
+# Fall back to zip if not.
+#
+# Archives are named using the output of `git describe --tags --long`, if Git
+# is found in the current PATH. Otherwise, they will simply be named
+# 'LOOT Archive'.
 
-# Delete the temporary folder if it already exists.
+# Python 3.3+ has shutil.which, but 2.7 doesn't.
+if 'which' in dir(shutil):
+    git = shutil.which('git.exe')
+else:
+    git = None
+    path = os.getenv('PATH')
+    for p in path.split(os.path.pathsep):
+        p = os.path.join(p, 'git.exe')
+        if os.path.exists(p) and os.access(p, os.X_OK):
+            git = p
+
+if not git:
+    # Git wasn't found in PATH, do a search (in GitHub install location).
+    github = os.path.join( os.getenv('LOCALAPPDATA'), 'GitHub' )
+    for folder, subdirs, files in os.walk(github):
+        for subdir in subdirs:
+            # Check for a <github>\<subdir>\cmd\git.exe
+            if os.path.exists( os.path.join( folder, subdir, 'cmd', 'git.exe') ):
+                git = os.path.join( folder, subdir, 'cmd', 'git.exe')
+
+
+if git:
+    args = [git, 'describe', '--tags', '--long']
+    output = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()
+    if len(output[1]) == 0:
+        archive_name = 'LOOT ' + output[0].decode('ascii')[:-1]
+    else:
+        archive_name = 'LOOT Archive'
+else:
+    archive_name = 'LOOT Archive'
+
+# Delete the temporary folder if it already exists, then create it.
 if os.path.exists(temp_path):
     shutil.rmtree(temp_path)
-
-# First make sure that the temporary folder for the archive exists.
-if not os.path.exists(temp_path):
-    os.makedirs(temp_path)
+os.makedirs(temp_path)
 
 # Now copy everything into the temporary folder.
 shutil.copy( os.path.join('..', 'build', 'Release', 'LOOT.exe'), temp_path )
@@ -73,11 +117,18 @@ shutil.copy( os.path.join('..', 'docs', 'LOOT Readme.html'), os.path.join(temp_p
 
 # Now compress the temporary folder. (Creating a zip because I can't get pylzma to work...)
 os.chdir(temp_path)
-zip = zipfile.ZipFile( os.path.join('..', archive_name), 'w', zipfile.ZIP_LZMA )
-for root, dirs, files in os.walk('.'):
-    for file in files:
-        zip.write(os.path.join(root, file))
-zip.close()
+
+sevenzip_path = os.path.join('C:\\', 'Program Files', '7-Zip', '7z.exe')
+if os.path.exists(sevenzip_path):
+    out_path = os.path.join('..', archive_name + '.7z')
+    args = [sevenzip_path, 'a', '-r', out_path]
+    subprocess.call(args)
+else:
+    zip = zipfile.ZipFile( os.path.join('..', archive_name + '.zip'), 'w', zipfile.ZIP_DEFLATED )
+    for root, dirs, files in os.walk('.'):
+        for file in files:
+            zip.write(os.path.join(root, file))
+    zip.close()
 os.chdir('..')
 
 # And finally, delete the temporary folder.