---
- name: Install Docker dependencies
  apt:
    name:
      - apt-transport-https
      - ca-certificates
      - curl
      - gnupg
      - lsb-release
    state: present
    update_cache: yes

- name: Add Docker GPG key
  apt_key:
    url: https://download.docker.com/linux/ubuntu/gpg
    state: present

- name: Add Docker repository
  apt_repository:
    repo: "deb [arch=amd64] https://download.docker.com/linux/ubuntu {{ ansible_distribution_release }} stable"
    state: present

- name: Install Docker
  apt:
    name:
      - docker-ce
      - docker-ce-cli
      - containerd.io
    state: present
    update_cache: yes

- name: Install Docker Compose
  apt:
    name: docker-compose-plugin
    state: present

- name: Start and enable Docker service
  systemd:
    name: docker
    state: started
    enabled: yes

- name: Wait for Docker to start
  pause:
    seconds: 5

- name: Verify Docker installation
  command: docker --version
  register: docker_version
  changed_when: false

- name: Show Docker version
  debug:
    msg: "Docker version: {{ docker_version.stdout }}"

- name: Verify Docker Compose installation
  command: docker compose version
  register: docker_compose_version
  changed_when: false

- name: Show Docker Compose version
  debug:
    msg: "Docker Compose version: {{ docker_compose_version.stdout }}"

- name: Setup Docker monitoring
  block:
    - name: Create scripts directory
      file:
        path: /opt/scripts
        state: directory
        mode: '0755'
      become: yes

    - name: Deploy Docker metrics script
      copy:
        content: |
          #!/bin/bash
          # Docker metrics script for Node Exporter textfile collector
          
          OUTFILE="/var/lib/node_exporter/textfile_collector/docker_metrics.prom"
          
          # Get container counts
          TOTAL_CONTAINERS=$(docker ps -a -q 2>/dev/null | wc -l)
          RUNNING_CONTAINERS=$(docker ps -q 2>/dev/null | wc -l)
          EXITED_CONTAINERS=$((TOTAL_CONTAINERS - RUNNING_CONTAINERS))
          
          # Write metrics in Prometheus format
          cat << EOF > $OUTFILE
          # HELP docker_containers_total Total number of Docker containers
          # TYPE docker_containers_total gauge
          docker_containers_total $TOTAL_CONTAINERS
          # HELP docker_containers_running Number of running Docker containers  
          # TYPE docker_containers_running gauge
          docker_containers_running $RUNNING_CONTAINERS
          # HELP docker_containers_exited Number of exited Docker containers
          # TYPE docker_containers_exited gauge
          docker_containers_exited $EXITED_CONTAINERS
          EOF
        dest: /opt/scripts/docker_metrics.sh
        mode: '0755'
      become: yes

    - name: Create systemd service for Docker metrics
      copy:
        content: |
          [Unit]
          Description=Docker metrics script
          After=docker.service
          
          [Service]
          User=root
          ExecStart=/opt/scripts/docker_metrics.sh
        dest: /etc/systemd/system/docker-metrics.service
        mode: '0644'
      become: yes

    - name: Create systemd timer for Docker metrics
      copy:
        content: |
          [Unit]
          Description=Run Docker metrics every 30 seconds
          
          [Timer]
          OnBootSec=1min
          OnUnitActiveSec=30s
          
          [Install]
          WantedBy=timers.target
        dest: /etc/systemd/system/docker-metrics.timer
        mode: '0644'
      become: yes

    - name: Ensure Node Exporter textfile directory exists
      file:
        path: /var/lib/node_exporter/textfile_collector
        state: directory
        owner: node_exporter
        group: node_exporter
        mode: '0755'
      become: yes

    - name: Enable and start Docker metrics timer
      systemd:
        name: docker-metrics.timer
        enabled: yes
        state: started
        daemon_reload: yes
      become: yes

    - name: Test Docker metrics script
      command: /opt/scripts/docker_metrics.sh
      register: metrics_test
      changed_when: false

    - name: Show Docker metrics test result
      debug:
        var: metrics_test.stdout