- name: Set up Docker
  hosts: "{{ target_host }}"
  become: yes

  vars:
    target_host: "localhost"
    docker_gpg_key_url: "https://download.docker.com/linux/ubuntu/gpg"
    docker_gpg_key_path: "/etc/apt/keyrings/docker.asc"

  tasks:
    - name: Check if Docker is installed
      command: which docker
      register: is_docker_present
      ignore_errors: yes

    - block:
        - name: Exit if docker is present
          debug:
            msg: "Docker already on host, ending play"
        - meta: end_play
      when: is_docker_present.rc == 0

    - name: Update apt cache
      apt:
        update_cache: yes

    - name: Install prerequisites
      apt:
        name:
          - ca-certificates
          - curl
        state: present

    - name: Ensure keyrings directory exists
      file:
        path: "/etc/apt/keyrings"
        state: directory
        mode: '0755'

    - name: Download Docker GPG key
      get_url:
        url: "{{ docker_gpg_key_url }}"
        dest: "{{ docker_gpg_key_path }}"
        mode: '0644'

    - name: Get system architecture
      shell: dpkg --print-architecture
      register: system_arch

    - name: Add Docker repository
      apt_repository:
        repo: "deb [arch={{ system_arch.stdout }} signed-by={{ docker_gpg_key_path }}] https://download.docker.com/linux/ubuntu {{ ansible_lsb.codename }} stable"
        state: present
        filename: docker

    - name: Update apt cache
      apt:
        update_cache: yes

    - name: Install Docker packages
      apt:
        name:
          - docker-ce
          - docker-ce-cli
          - containerd.io
          - docker-buildx-plugin
          - docker-compose-plugin
        state: latest
      notify: Restart Docker

    - name: Verify Docker installation by running the hello world image
      command: docker run hello-world
      register: hello_world_output
      ignore_errors: true

    - name: Display hello-world output
      debug:
        var: hello_world_output.stdout_lines

    - name: Add user to docker group
      user:
        name: "{{ ansible_user }}"
        groups: docker
        append: true

  handlers:
    - name: Restart Docker
      service:
        name: docker
        state: restarted