#!/bin/bash
# Fetch the PID of git commit command just ran
PID=$(ps aux | grep "git commit" | tail -1 |  awk '{print $2}')
# If unable to fetch the PID, give it another try
if [[ -z "$PID" ]]; then
  echo "unable to get process id, please try again.."
  exit 1
fi
# Fetch the command used
COMMAND=$(ps -p "$PID" -o args)
# At times, unable to fetch the command used from PID
# Checking Line counts and exits
COMMAND_LINE_COUNT=$(ps -p "$PID" -o args | wc -l)
if [[ $COMMAND_LINE_COUNT -eq 1 ]]; then
  echo "unable to fetch the command, please try again.."
  exit 1
fi
COMMAND=$(echo "$COMMAND" | tail -1)

# Print the Command observed
# echo $COMMAND

# Variable to store if the command is ammend
is_ammend=false

# Check if command is amend by regex match
if [[ $COMMAND == *"amend"* ]]; then
    is_ammend=true
fi

# If the issued command is ammend, validate the current author and previous commit author
if [[ $is_ammend = "true" ]]; then
  echo "Looks like you are ammending the code.. "
  PREV_AUTHOR=$(git log --pretty=format:"%an" | head -1)
  CURRENT_AUTHOR=$(git config --global user.name)
  if [ "$PREV_AUTHOR" != "$CURRENT_AUTHOR" ]; then
    echo "Current Author $CURRENT_AUTHOR"
    echo "Previous Author $PREV_AUTHOR"
    echo "ammends to other's commit is not supported..."
    exit 1
  fi
fi

exit 0