bash script to generate work specifications from git log and outputs generated markdown

git-worklog.sh

#!/bin/bash

# Current month
# ./git-worklog.sh

# Specific month and year
# ./git-worklog.sh --month 3 --year 2025

# Custom output file
# ./git-worklog.sh --month 3 --year 2025 --output april-2025-worklog.md

REPO_PATH="."
cd "$REPO_PATH" || exit 1

MONTH=""
YEAR=""
OUTPUT_FILE="worklog.md"
EMAIL=""

while [[ $# -gt 0 ]]; do
  case $1 in
    --month)
      MONTH="$2"
      shift 2
      ;;
    --year)
      YEAR="$2"
      shift 2
      ;;
    --output)
      OUTPUT_FILE="$2"
      shift 2
      ;;
    *)
      echo "Unknown option: $1"
      exit 1
      ;;
  esac
done

read -rp "Enter your email: " EMAIL

AUTHOR_NAME=$(git log --author="$EMAIL" --format='%an' --reverse | head -n 1)
[[ -z "$AUTHOR_NAME" ]] && AUTHOR_NAME="Unknown Author"

if [[ -z "$MONTH" ]]; then
  START_DATE=$(date +%Y-%m-01)
  MONTH=$(date +%-m)
  YEAR=$(date +%Y)
  END_DATE="now"
else
  if (( MONTH < 10 )); then
    MONTH="0$MONTH"
  fi
  [[ -z "$YEAR" ]] && YEAR=$(date +%Y)
  START_DATE="${YEAR}-${MONTH}-01"
  END_DATE=$(date -j -f "%Y-%m-%d" "$START_DATE" "+%Y-%m-01" | date -v+1m -v-1d "+%Y-%m-%d")
fi

MONTH_NAME=$(date -j -f "%m" "$MONTH" "+%B")
echo "# Work Specifications for $MONTH_NAME $YEAR" > "$OUTPUT_FILE"
echo "" >> "$OUTPUT_FILE"
echo "Author: $AUTHOR_NAME <$EMAIL>" >> "$OUTPUT_FILE"
echo "" >> "$OUTPUT_FILE"

git log --author="$EMAIL" --since="$START_DATE" --until="$END_DATE" \
  --pretty=format:'%h|%ci|%s' |
sort -t'|' -k2 |
while IFS="|" read -r hash datetime subject; do
  raw_date=$(echo "$datetime" | cut -d' ' -f1)
  if formatted_date=$(date -jf "%Y-%m-%d" "$raw_date" "+%A %-d.%m.%Y" 2>/dev/null); then
    echo "$raw_date|$formatted_date|$hash|$subject"
  fi
done |
sort -t'|' -k1 |
awk -F'|' -v outfile="$OUTPUT_FILE" '
BEGIN { last_day = "" }
{
    if ($1 != last_day) {
        if (last_day != "") print "" >> outfile
        print "## " $2 "\n" >> outfile
        last_day = $1
    }
    printf "- (%s) %s\n", $3, $4 >> outfile
}
'

echo "✅ Worklog saved to $OUTPUT_FILE"