Remove git branches older than x

remove-old-branches.sh

#!/bin/bash

# Function to get the cutoff date
get_cutoff_date() {
    if [[ "$OSTYPE" == "darwin"* ]]; then
        # macOS
        date -v-12m +%s
    else
        # Linux and others
        date -d "12 months ago" +%s
    fi
}

# Function to convert epoch to relative time
epoch_to_relative() {
    local epoch=$1
    local now=$(date +%s)
    local diff=$((now - epoch))

    local days=$((diff / 86400))
    local hours=$(( (diff % 86400) / 3600 ))
    local minutes=$(( (diff % 3600) / 60 ))
    local seconds=$((diff % 60))

    if [[ $days -gt 0 ]]; then
        echo "$days days ago"
    elif [[ $hours -gt 0 ]]; then
        echo "$hours hours ago"
    elif [[ $minutes -gt 0 ]]; then
        echo "$minutes minutes ago"
    else
        echo "$seconds seconds ago"
    fi
}

# Set the cutoff date to 6 months ago
cutoff=$(get_cutoff_date)

# Function to delete branches
delete_branches() {
    local branch_type=$1
    local branches=$2

    for branch in $branches; do
        # Skip the current branch and main/master branches
        if [[ "$branch" == "$(git rev-parse --abbrev-ref HEAD)" ]] || [[ "$branch" == "main" ]] || [[ "$branch" == "master" ]]; then
            continue
        fi
    
        # Get the timestamp of the latest commit
        if [[ $branch_type == "local" ]]; then
            timestamp=$(git log -1 --format=%at "$branch")
        else
            timestamp=$(git log -1 --format=%at "origin/$branch")
        fi

        if [[ $timestamp -lt $cutoff ]]; then
            relative_time=$(epoch_to_relative $timestamp)
            echo "Branch ($branch_type) $branch - last updated $relative_time"
            if [[ $branch_type == "local" ]]; then
                git branch -d "$branch"
                echo "Deleted local branch: $branch"
            else
                git push origin --delete "$branch"
                echo "Deleted remote branch: $branch"
            fi
        fi
    done
}

# Update the local list of remote branches
git fetch --all --prune

# Get all local branches
local_branches=$(git branch --sort=-committerdate --format="%(refname:short)")

# Get all remote branches
remote_branches=$(git branch -r --sort=-committerdate | grep -v '\->' | sed 's/origin\///')

# Delete old local branches
delete_branches "local" "$local_branches"

# Delete old remote branches
delete_branches "remote" "$remote_branches"

echo "Branch cleanup completed."