#!/usr/bin/env bash
# 20-docker — Docker Engine + Compose v2 plugin. $USER added to docker group.

step_name="docker"
step_desc="docker engine + compose v2, add \$USER to docker group"
step_run="run_docker"

run_docker() {
  log "installing docker + compose v2"
  if command -v docker >/dev/null 2>&1 && docker compose version >/dev/null 2>&1; then
    ok "docker + compose v2 already installed"
  else
    case "$DISTRO" in
      arch)   sudo_ pacman -Sy --noconfirm --needed docker docker-compose ;;
      debian) _docker_debian ;;
    esac
  fi

  # enable + start (best-effort; skip inside containers without systemd)
  if command -v systemctl >/dev/null 2>&1 && systemctl is-system-running >/dev/null 2>&1; then
    sudo_ systemctl enable --now docker.service containerd.service 2>/dev/null \
      || warn "could not enable docker.service (no systemd?)"
  else
    warn "systemctl unavailable — start docker manually if needed"
  fi

  # add current user to docker group
  if getent group docker >/dev/null 2>&1; then
    if id -nG "$USER" | grep -qw docker; then
      ok "$USER already in docker group"
    else
      sudo_ usermod -aG docker "$USER"
      ok "$USER added to docker group (log out/in or 'newgrp docker' to use it)"
    fi
  fi
}

_docker_debian() {
  sudo_ install -m 0755 -d /etc/apt/keyrings
  curl -fsSL https://download.docker.com/linux/$(. /etc/os-release; echo "$ID")/gpg \
    | sudo_ gpg --dearmor -o /etc/apt/keyrings/docker.gpg
  sudo_ chmod a+r /etc/apt/keyrings/docker.gpg
  local codename; codename="$(. /etc/os-release; echo "$VERSION_CODENAME")"
  echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] \
https://download.docker.com/linux/$(. /etc/os-release; echo "$ID") $codename stable" \
    | sudo_ tee /etc/apt/sources.list.d/docker.list >/dev/null
  sudo_ apt-get update -y
  sudo_ apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
}