From 5c4bc0653e601ddddde50e1337ffac2df1d48751 Mon Sep 17 00:00:00 2001
From: Olga Shilyagina <olg.and.ipf@gmail.com>
Date: Tue, 2 Oct 2018 18:35:49 +0300
Subject: [PATCH] CLI version option

Solution for Issue #15
---
 README.md      |  2 ++
 snowsaw/cli.py | 26 +++++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 348276e..fb7868b 100644
--- a/README.md
+++ b/README.md
@@ -170,6 +170,8 @@ A terminal help page can be shown by using the `-h`/`--help` option.
 | `-p`, `--plugin` | `PLUGIN` | No | Load `PLUGIN` as a plugin. |
 | `--disable-core-plugins` | - | No | Disable all core plugins. |
 | `--plugin-dir` | `PLUGIN_DIR` | No | Load all plugins in `PLUGIN_DIR`. |
+| `--version`  | | No | Prints current version of snowsaw |
+
 
 ## Configuration
 snowsaw uses [JSON](http://json.org) configuration files to specify tasks on how to set up your dotfiles.
diff --git a/snowsaw/cli.py b/snowsaw/cli.py
index e52db47..df58ce0 100644
--- a/snowsaw/cli.py
+++ b/snowsaw/cli.py
@@ -8,6 +8,7 @@
 from argparse import ArgumentParser
 import glob
 import os
+import subprocess
 
 from .config import ConfigReader, ReadingError
 from .dispatcher import Dispatcher, DispatchError
@@ -27,11 +28,12 @@ def add_options(parser):
     parser.add_argument('-q', '--quiet', dest='quiet', action='store_true', help='suppress most output')
     parser.add_argument('-v', '--verbose', dest='verbose', action='store_true', help='enable verbose output')
     parser.add_argument('-s', '--snowblocks-directory', nargs=1, dest='snowblocks_directory',
-                        help='base snowblock directory to run all tasks of', metavar='SNOWBLOCKSDIR', required=True)
+                        help='base snowblock directory to run all tasks of', metavar='SNOWBLOCKSDIR')
     parser.add_argument('-c', '--config-file', nargs=1, dest='config_file', help='run tasks for the specified snowblock', metavar='CONFIGFILE')
     parser.add_argument('-p', '--plugin', action='append', dest='plugins', default=[], help='load PLUGIN as a plugin', metavar='PLUGIN')
     parser.add_argument('--disable-core-plugins', dest='disable_core_plugins', action='store_true', help='disable all core plugins')
     parser.add_argument('--plugin-dir', action='append', dest='plugin_dirs', default=[], metavar='PLUGIN_DIR', help='load all plugins in PLUGIN_DIR')
+    parser.add_argument('--version', action='store_true', help='print snowsaw version')
 
 
 def read_config(config_file):
@@ -58,6 +60,28 @@ def main():
         add_options(parser)
         options = parser.parse_args()
 
+        if options.version :
+            """
+            Just print version end exit. Don't need to process other arguments.
+            Change directory to ensure git-related commands are called inside
+            snowsaw repository and than change it back
+            """
+            caller_dir = os.getcwd()
+            snowsaw_dir = os.path.dirname(os.path.realpath(__file__))
+            os.chdir(snowsaw_dir)
+            try:
+                current_version = subprocess.check_output(["git", "describe"]).strip()
+            except subprocess.CalledProcessError as Error :
+                current_version = "Not tagged (development) version"
+            print(current_version)
+            os.chdir(caller_dir)
+            return current_version
+        elif not options.snowblocks_directory :
+            """
+            Since it's not a version request, check required arguments existance
+            """
+            parser.error("argument -s/--snowblocks-directory is required")
+
         if options.super_quiet:
             log.set_level(Level.WARNING)
         if options.quiet: