#!/bin/bash

set -e

echo "🧠 Detecting OS..."

# Detect OS
if [ -f /etc/os-release ]; then
    . /etc/os-release
    OS=$ID
    VERSION_ID=$VERSION_ID
else
    echo "❌ Cannot determine OS. /etc/os-release not found."
    exit 1
fi

echo "📦 Installing Docker for: $OS $VERSION_ID"

# Install Docker based on detected OS
case "$OS" in
    ubuntu|debian)
        sudo apt-get update
        sudo apt-get install -y ca-certificates curl gnupg lsb-release

        sudo install -m 0755 -d /etc/apt/keyrings
        curl -fsSL https://download.docker.com/linux/$OS/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
        sudo chmod a+r /etc/apt/keyrings/docker.gpg

        echo \
        "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/$OS \
        $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

        sudo apt-get update
        sudo apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
        ;;

    centos|rhel)
        sudo yum install -y yum-utils
        sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
        sudo yum install -y docker-ce docker-ce-cli containerd.io docker-compose-plugin
        ;;

    fedora)
        sudo dnf -y install dnf-plugins-core
        sudo dnf config-manager --add-repo https://download.docker.com/linux/fedora/docker-ce.repo
        sudo dnf install -y docker-ce docker-ce-cli containerd.io docker-compose-plugin
        ;;

    alpine)
        sudo apk update
        sudo apk add docker docker-cli docker-compose
        ;;

    arch)
        sudo pacman -Sy --noconfirm docker docker-compose
        ;;

    *)
        echo "❌ Unsupported OS: $OS"
        exit 1
        ;;
esac

echo "✅ Docker installed successfully."

# Start and enable Docker
echo "🚀 Starting Docker..."
sudo systemctl enable docker
sudo systemctl start docker

# Add current user to docker group
if ! groups $USER | grep -q docker; then
    echo "👤 Adding $USER to docker group (you may need to log out and in again)..."
    sudo usermod -aG docker $USER
fi

echo "✅ Done! You can now run Docker as your user."
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