#!/bin/bash
# Docker installation script using official convenience script
# https://docs.docker.com/engine/install/
# This script always uses the latest installation method from Docker

set -e

yellow='\033[1;33m'
green='\033[1;32m'
red='\033[1;31m'
no_color='\033[0m'

need_install_docker=0

# Add user to docker group
setup_docker_group() {
    echo ""
    getent group docker || sudo groupadd docker

    if id -nG "$USER" | grep -qw docker; then
        echo -e "${green}User '$USER' is already in the docker group${no_color}"
        return
    fi

    echo -e "${yellow}Do you want to add user '$USER' to the docker group?${no_color}"
    echo "This allows running Docker commands without sudo."
    echo -e "${yellow}Note: You will need to log out and back in for this to take effect.${no_color}"
    read -p "Add to docker group? [y/N]: " -n 1 -r
    echo

    if [[ $REPLY =~ ^[Yy]$ ]]; then
        sudo usermod -aG docker "$USER"
        echo -e "${green}User '$USER' added to docker group successfully!${no_color}"
        echo -e "${yellow}Please log out and back in for this to take effect.${no_color}"
    else
        echo -e "${yellow}Skipped adding user to docker group. You can add it later with:${no_color}"
        echo -e "${yellow}  sudo usermod -aG docker \$USER${no_color}"
    fi
}

install_docker() {
    echo -e "${yellow}Installing Docker using official convenience script...${no_color}"
    echo -e "${yellow}This script is always up-to-date from https://get.docker.com${no_color}"
    need_install_docker=1

    # Use Docker's official convenience script
    # https://docs.docker.com/engine/install/ubuntu/#install-using-the-convenience-script
    curl -fsSL https://get.docker.com -o /tmp/get-docker.sh
    sudo sh /tmp/get-docker.sh
    rm -f /tmp/get-docker.sh

    setup_docker_group

    # Verify Docker Compose plugin is installed
    if docker compose version &>/dev/null; then
        echo -e "${green}Docker Compose plugin is available: $(docker compose version)${no_color}"
    fi

    echo -e "${green}Docker installed successfully!${no_color}"
    echo -e "${yellow}Note: You may need to log out and back in for group changes to take effect.${no_color}"
}

# Parse command line arguments first
while [[ "$1" != "" ]]; do
    case "$1" in
        --docker)
            install_docker
            exit 0
            ;;
        --add)
            if ! command -v "docker" &>/dev/null; then
                echo -e "${red}Docker is not installed. Please install Docker first.${no_color}"
                echo "Run: bash $0 --docker"
                exit 1
            fi
            setup_docker_group
            exit 0
            ;;
        --help|-h)
            echo "Usage: $0 [OPTIONS]"
            echo ""
            echo "Options:"
            echo "  --docker       Force reinstall Docker"
            echo "  --add          Add current user to docker group"
            echo "  --help, -h     Show this help message"
            echo ""
            echo "Supported OS: Ubuntu, Debian, CentOS, Fedora"
            echo "Docker Compose is included as a plugin (docker-compose-plugin)"
            echo "See https://docs.docker.com/engine/install/ for more information"
            exit 0
            ;;
        *)
            echo -e "${red}Unknown option: $1${no_color}"
            echo "Use --help for usage information"
            exit 1
            ;;
    esac
    shift
done

# Main logic - only runs if no arguments provided
if ! command -v "docker" &>/dev/null; then
    install_docker
fi

if [[ "$need_install_docker" == 0 ]]; then
    echo -e "${green}Docker is already installed${no_color}"
    echo "You can use --docker to reinstall or --add to join docker group"
    if docker compose version &>/dev/null; then
        echo -e "${green}Docker Compose plugin: $(docker compose version)${no_color}"
    fi
fi