Configure signed commits with SSH keys

#!/bin/bash

# Function to check if we're in a git repository
check_git_repo() {
    if ! git rev-parse --git-dir > /dev/null 2>&1; then
        echo "Error: Not a git repository"
        exit 1
    fi
}

# Function to generate SSH key
generate_ssh_key() {
    local key_comment=$1

    if [ -f ~/.ssh/git_signing_key ]; then
        echo "Warning: SSH key git_signing_key already exists"
        read -p "Do you want to overwrite it? (y/n) " -n 1 -r
        echo
        if [[ ! $REPLY =~ ^[Yy]$ ]]; then
            echo "Aborting..."
            exit 1
        fi
    fi

    ssh-keygen -t ed25519 -C "$key_comment" -f ~/.ssh/git_signing_key -N ""

    # Set correct permissions
    chmod 600 ~/.ssh/git_signing_key
    chmod 644 ~/.ssh/git_signing_key.pub
}

# Function to configure git
configure_git() {
    echo -e "\nSetting local git configuration to use the generated signing key.."

    git config gpg.format ssh
    git config user.signingkey "~/.ssh/git_signing_key.pub"
    git config commit.gpgsign true

    echo -e "Git configuration complete!\n\n"
}

# Function to display public key
display_key() {
    echo "Here's your public key to add to GitHub:"
    echo "----------------------------------------"
    cat ~/.ssh/git_signing_key.pub
    echo "----------------------------------------"
    echo "Add this key to GitHub by visiting: https://github.com/settings/keys"
    echo "Make sure to choose the key type as 'Signing Key' when adding it. Once done, your setup is complete."
}

# Main script
main() {
    check_git_repo

    # Get user input
    read -p "Enter a comment for your key (e.g., your name, email, etc): " key_comment

    # Setup steps
    generate_ssh_key "$key_comment"
    configure_git
    display_key
}

# Run main function
main

chmod +x setup_git_signed_commits.sh

./setup_git_signed_commits.sh