[tools] Version script without params now shows actual values

Signed-off-by: Alexander Borsuk <me@alex.bio>

tools/unix/version.sh

@@ -1,21 +1,8 @@
 #!/bin/bash
-
+# Should be used everywhere to generate a consistent version number based
+# on the date of the last commit and a number of commits on that day.
 set -euo pipefail
 
-function usage {
-  cat << EOF
-Prints Organic Maps version in specified format.
-Version is the last git commit's date plus a number of commits on that day.
-Usage: $0 format
-Where format is one of the following arguments:
-  ios_version   2021.12.26
-  ios_build     3
-  android_name  2021.12.26-3
-  android_code  21122603
-  git_hash      abcdef01
-EOF
-}
-
 # Note: other ways to get date use the "when commit was rebased" date.
 # This approach counts a number of commits each day based on author's commit date.
 COUNT_AND_DATE=( $(git log --date=short --pretty=format:%ad --date=format:'%Y.%m.%d' --since="30 days ago" | sort | uniq -c | tail -1) )
@@ -26,16 +13,20 @@ fi
 DATE=${COUNT_AND_DATE[1]}
 COUNT=${COUNT_AND_DATE[0]}
 
-case "${1:-}" in
-  ios_version)
-    echo $DATE
-    ;;
-  ios_build)
-    echo $COUNT
-    ;;
-  android_name)
-    echo $DATE-$COUNT
-    ;;
+
+function ios_version {
+  echo "$DATE"
+}
+
+function ios_build {
+  echo "$COUNT"
+}
+
+function  android_name {
+  echo "$DATE-$COUNT"
+}
+
+function android_code {
   # RR_yy_MM_dd_CC
   # RR - reserved to identify special markets, max value is 21.
   # yy - year
@@ -44,15 +35,31 @@ case "${1:-}" in
   # CC - the number of commits from the current day
   # 21_00_00_00_00 is the the greatest value Google Play allows for versionCode.
   # See https://developer.android.com/studio/publish/versioning for details.
-  android_code)
-    CUT_YEAR=${DATE:2}
-    echo ${CUT_YEAR//./}$(printf %02d $COUNT)
-    ;;
-  git_hash)
-    git describe --match="" --always --abbrev=8 --dirty
-    ;;
-  *)
-    usage
-    exit 1
-    ;;
-esac
+  local cutYear=${DATE:2}
+  echo "${cutYear//./}$(printf %02d "$COUNT")"
+}
+
+function git_hash {
+  git describe --match="" --always --abbrev=8 --dirty
+}
+
+function usage {
+  cat << EOF
+Prints Organic Maps version in specified format.
+Version is the last git commit's date plus a number of commits on that day.
+Usage: $0 <format>
+Where format is one of the following arguments (shows current values):
+  ios_version   $(ios_version)
+  ios_build     $(ios_build)
+  android_name  $(android_name)
+  android_code  $(android_code)
+  git_hash      $(git_hash)
+EOF
+}
+
+if [ -z ${1:-} ] || [[ ! $(type -t "$1") == function ]]; then
+  usage
+  exit 1
+else
+  "$1"
+fi