committer_stats.bash

#!/bin/bash

if [ -z "${1}" ]
then
    GIT_USER="$(git config --global --list | grep user.name | cut -d= -f2)"
else
    GIT_USER="${1}"
fi

if [ -z "${2}" ]
then
    AfterDate=""
else
    AfterDate="--after=${2}"
fi

main() {
        exit_if_not_repository
        local branch changes
        local user_commits all_commits
        local average_delta percentage typical_time
        branch="$(get_branch)"
        changes="$(lines_changed)"
        user_commits="$(get_user_commits)"
        all_commits="$(get_all_commits)"
        percentage="$(calculate_percentage ${user_commits} ${all_commits})"
        average_delta="$(get_average_delta $((changes)) ${user_commits})"
        typical_times="$(typical_commit_times)"
        echo "Stats for ${GIT_USER} on ${branch}:"
        echo "   Commits: ${user_commits} (${percentage}% of all commits)"
        echo "   Lines: ${changes}"
        echo "   Total delta: $((changes))"
        echo "   Average delta/commit: ${average_delta}"
        echo "   Typical commit times (UTC):"
        echo "${typical_times}"
        echo ""
        echo "Stats for all users on ${branch}:"
        echo "   Commits: ${all_commits}"
}

exit_if_not_repository() {
    git status 1> /dev/null 2>&1 || print_error_and_exit
}

print_error_and_exit() {
    echo "fatal: Not a git repository" >&2
    exit 1
}

get_branch() {
    git branch | grep '^\*' | cut -d' ' -f2
}

lines_changed() {
    git log ${AfterDate} --author="${GIT_USER}" --pretty=tformat: --numstat \
        | awk 'BEGIN {ins=0; rem=0}; {ins+=$1; rem+=$2} END {print "+" ins " -" rem}'
}

get_user_commits() {
    git rev-list HEAD --count --author="${GIT_USER}" ${AfterDate}
}

get_all_commits() {
    git rev-list HEAD --count ${AfterDate}
}

calculate_percentage() {
    local num denom
    num="${1}"
    denom="${2}"
    echo "scale=6; ${num}/${denom}" | bc | awk '{printf "%.4f\n", $0*100}'
}

get_average_delta() {
    local changes user_commits
    changes="${1}"
    user_commits="${2}"
    if [ ${changes} -eq 0 ]
    then
        echo "0"
    else
        echo "$((changes / user_commits))"
    fi
}

typical_commit_times() {
    TZ=UTC git log ${AfterDate} --author="${GIT_USER}" \
      --pretty=format:"%ad" --date=iso-local \
        | awk '{print $2}' \
        | cut -d: -f1 \
        | sort \
        | uniq -c \
        | sort -nr \
        | head -n3 \
        | awk '{print $2 ":00-" sprintf("%02d", $2+1) ":00 (" $1 " commits)"}' \
        | sed 's/^/      /g'
}

main