#!/bin/bash

set -e

echo "🛠️ Detecting OS..."
OS=$(uname -s)

install_docker_linux() {
  echo "🔧 Installing Docker on Linux..."

  # Remove old versions
  sudo apt-get remove -y docker docker-engine docker.io containerd runc || true

  # Install dependencies
  sudo apt-get update
  sudo apt-get install -y \
    ca-certificates \
    curl \
    gnupg \
    lsb-release

  # Add Docker's official GPG key
  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

  # Add Docker's repo
  echo \
    "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/$(. /etc/os-release && echo "$ID") \
    $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

  # Install Docker and Compose
  sudo apt-get update
  sudo apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

  # Enable and start Docker
  sudo systemctl enable docker
  sudo systemctl start docker

  # Add user to docker group
  sudo usermod -aG docker "$USER"

  echo "✅ Docker installed. Please log out and log back in for docker group to take effect."
}

install_docker_windows_message() {
  echo "🪟 Detected Windows system."
  echo "👉 Please install Docker Desktop from: https://www.docker.com/products/docker-desktop/"
  echo "It includes Docker Engine + Compose and integrates with WSL2."
  echo ""
  echo "Make sure to:"
  echo "  - Enable WSL2 backend during install"
  echo "  - Share your drives if needed (for volume mounting)"
}

case "$OS" in
  Linux)
    install_docker_linux
    ;;
  Darwin)
    echo "🍏 macOS detected. Please use Docker Desktop: https://www.docker.com/products/docker-desktop"
    ;;
  MINGW*|CYGWIN*|MSYS*|Windows_NT)
    install_docker_windows_message
    ;;
  *)
    echo "❌ Unsupported OS: $OS"
    exit 1
    ;;
esac