Fix: show help page when not inside a git repository

Ensure the usage function is called to display the help page if the script is not run inside a git repository.

#168

git-quick-stats

@@ -17,7 +17,7 @@ _since=${_GIT_SINCE:-}
 if [[ -n "${_since}" ]]; then
     _since="--since=$_since"
 else
-    _since="--since=$(git log --reverse --format='%ad' --date=iso | head -n1)"
+    _since="--since=$(git log --reverse --format='%ad' | head -n1)"
 fi
 
 # End of git log date. Respects all git datetime formats
@@ -761,47 +761,6 @@ function commitsPerDay() {
         --date=short --format='%ad' $_log_options $_pathspec | sort | uniq -c
 }
 
-################################################################################
-# DESC: Convert a timestamp to a date string to handle git's date formats
-# ARGS: $1: Timestamp
-# OUTS: Echoes a four-digit year
-################################################################################
-function parse_year() {
-    local date_str="$1"
-    local year
-    local timestamp
-    local default_git_date_regex
-
-    # Handle the raw UNIX timestamp format i.e. 1697375696 +0000
-    if [[ "$date_str" =~ ^[0-9]+(\ [+-][0-9]{4})?$ ]]; then
-        timestamp=$(echo "$date_str" | awk '{print $1}')
-        year=$(date -d "@$timestamp" '+%Y' 2>/dev/null)
-    else
-        # Default case can get funky. We need to create a clever regex to
-        # handle the default case which is like Mon Oct 15 12:34:56 2023 +0000
-        # Let's make this explicit for future devs to follow along.
-        default_git_date_regex='^' # Start from the beginning of the string
-        default_git_date_regex+='[A-Za-z]{3}\ ' # Day abbrev
-        default_git_date_regex+='[A-Za-z]{3}\ ' # Month abbrev
-        default_git_date_regex+='[0-9]{1,2}\ ' # Day of the month
-        default_git_date_regex+='[0-9]{2}:[0-9]{2}:[0-9]{2}\ ' # Time HH:MM:SS
-        default_git_date_regex+='[0-9]{4}\ ' # Year
-        default_git_date_regex+='[+-][0-9]{4}$' # Timezone offset
-
-        if [[ "$date_str" =~ $default_git_date_regex ]]; then
-            # Move the year before the time to match a format that Date can parse
-            date_str=$(echo "$date_str" | awk '{print $1, $2, $3, $5, $4, $6}')
-        elif [[ "$date_str" =~ ^[0-9]{1,2}/[0-9]{1,2}/[0-9]{2,4} ]]; then
-            # Handle DD/MM/YYYY format
-            date_str=$(echo "$date_str" | awk -F'/' '{print $2"/"$1"/"$3}')
-        fi
-        # Extract the final date
-        year=$(date -d "$date_str" '+%Y' 2>/dev/null)
-    fi
-
-    echo "$year"
-}
-
 ################################################################################
 # DESC: Displays a horizontal bar graph based on total commits per year
 # ARGS: None
@@ -810,38 +769,30 @@ function parse_year() {
 function commitsByYear() {
     optionPicked "Git commits by year:"
     local year startYear endYear __since __until
+    startYear=$(echo "$_since" | sed -E 's/^.* ([0-9]{4})( .*)?$/\1/')
+    endYear=$(echo "$_until" | sed -E 's/^.* ([0-9]{4})( .*)?$/\1/')
 
-    # Extract the date strings from $_since and $_until
-    since_date="${_since#--since=}"
-    until_date="${_until#--until=}"
-
-    # Grab the four digit year from $_since and $_until
-    startYear=$(parse_year "$since_date")
-    endYear=$(parse_year "$until_date")
-    
     echo -e "\tyear\tsum"
-    # Add time strings to make these a touch more robust
-    for year in $(seq "$startYear" "$endYear"); do
-        if [[ "$year" = "$startYear" ]]; then
-            __since=$_since
-            __until="--until=$year-12-31 23:59:59"
-        elif [[ "$year" = "$endYear" ]]; then
-            __since="--since=$year-01-01 00:00:00"
-            __until=$_until
+    for year in $(seq "$startYear" "$endYear")
+    do
+        if [ "$year" = "$startYear" ]
+        then
+          __since=$_since
+          __until="--until=$year-12-31"
+        elif [ "$year" = "$endYear" ]
+        then
+          __since="--since=$year-01-01"
+          __until=$_until
         else
-            __since="--since=$year-01-01 00:00:00"
-            __until="--until=$year-12-31 23:59:59"
+          __since="--since=$year-01-01"
+          __until="--until=$year-12-31"
         fi
-        
-        # Count commits directly using git rev-list instead of git log
-        commit_count=$(
-            git rev-list --count $_merges \
-            "$__since" "$__until" HEAD $_log_options
-        )
-        echo -e "\t$year\t$commit_count"
-        # TODO: The bar graph can get funky when there are only a handful of
-        # commits. We can set a max length to try to fix this, but this is a
-        # bit of a problem across all the bar graphs.
+
+        echo -en "\t$year\t"
+        git -c log.showSignature=false shortlog -n $_merges --format='%ad %s' \
+            "$__since" "$__until" $_log_options | grep -cE \
+              " \w\w\w [0-9]{1,2} [0-9][0-9]:[0-9][0-9]:[0-9][0-9] $year " \
+                || continue
     done | awk '{
         count[$1] = $2
         total += $2
@@ -1035,8 +986,8 @@ function suggestReviewers() {
 checkUtils
 
 # Check if we are currently in a git repo.
-if ! git rev-parse --is-inside-work-tree > /dev/null; then
-    echo "ERROR: You need to be inside a git repo to parse stats!"
+if ! git rev-parse --is-inside-work-tree > /dev/null 2>&1; then
+    echo "Not inside a git repository."
     usage
     exit 1
 fi