#!/bin/bash

################################################################################
# Docker Setup Script
################################################################################
# 
# Description:
#   Comprehensive automated setup script for Docker development environments.
#   This script prepares Ubuntu/Debian systems with all necessary tools for
#   containerized application development and deployment.
#
# What this script does:
#   1. System Updates
#      - Updates apt package lists
#      - Upgrades all installed packages to latest versions
#      - Reports number of packages upgraded
#
#   2. Docker Installation (if not present)
#      - Adds Docker's official GPG key and repository
#      - Installs Docker Engine, CLI, containerd
#      - Installs Docker Buildx and Compose plugins
#      - Enables Docker service to start on boot
#      - Verifies Docker daemon is running
#
#   3. Docker Group Configuration
#      - Creates docker group if it doesn't exist
#      - Adds the current user to docker group
#      - Enables sudo-less Docker commands (after re-login)
#      - Sets up proper group permissions
#
#   4. Docker Compose V2
#      - Checks for Docker Compose plugin
#      - Installs docker-compose-plugin if missing
#      - Verifies installation and version
#
#   5. GitHub CLI Installation
#      - Adds GitHub CLI official repository
#      - Installs latest version of 'gh' command
#      - Verifies installation
#
#   6. Container Directory Setup
#      - Creates /srv/containers/ directory structure
#      - Sets ownership to root:docker
#      - Applies 770 permissions (rwxrwx---)
#      - Configures ACL for inherited permissions
#      - Ensures all docker group members can create/manage containers
#
#   7. Verification & Summary
#      - Tests Docker access for current user
#      - Displays installation summary
#      - Provides next steps for activation
#
# Requirements:
#   - Ubuntu 20.04+ or Debian 10+
#   - sudo privileges
#   - Internet connection
#
# Usage:
#   Quick install:
#     curl -sL https://raw.githubusercontent.com/alexisskeates/docker-setup-script/main/docker-setup.sh | sudo bash
#
#   Manual download and run:
#     curl -O https://raw.githubusercontent.com/alexisskeates/docker-setup-script/main/docker-setup.sh
#     chmod +x docker-setup.sh
#     sudo ./docker-setup.sh
#
# Post-installation:
#   After running, you must activate docker group membership:
#     Option 1: Log out and log back in (recommended)
#     Option 2: Run 'newgrp docker' in current session
#
# Author: Alexis Keates
# Repository: https://github.com/alexisskeates/docker-setup-script
# License: MIT
#
################################################################################

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Function to print colored output
print_status() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1"
}

print_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

print_section() {
    echo -e "${BLUE}[SECTION]${NC} $1"
}

# Check if running with elevated privileges
if [[ $EUID -ne 0 ]]; then
    print_error "This script must be run with sudo"
    print_error "Usage: curl -sL https://raw.githubusercontent.com/alexisskeates/docker-setup-script/main/docker-setup.sh | sudo bash"
    exit 1
fi

# Get the original user who ran sudo
if [[ -n "$SUDO_USER" ]]; then
    ORIGINAL_USER="$SUDO_USER"
    ORIGINAL_USER_HOME=$(eval echo "~$SUDO_USER")
else
    print_error "Could not determine original user. Please run with sudo, not as root directly."
    exit 1
fi

print_status "Running as: $(whoami) (original user: $ORIGINAL_USER)"
echo

# ============================================================================
# SECTION 1: System Updates
# ============================================================================
print_section "Checking for system updates..."

print_status "Updating package lists..."
if apt-get update; then
    print_status "Package lists updated successfully"
else
    print_error "Failed to update package lists"
    exit 1
fi

print_status "Checking for upgradeable packages..."
UPGRADABLE=$(apt list --upgradable 2>/dev/null | tail -n +2 | wc -l)

if [[ $UPGRADABLE -gt 0 ]]; then
    print_status "Found $UPGRADABLE upgradeable package(s)"
    print_status "Upgrading system packages (this may take a few minutes)..."
    if DEBIAN_FRONTEND=noninteractive apt-get upgrade -y; then
        print_status "System packages upgraded successfully"
    else
        print_warning "Some packages failed to upgrade, but continuing..."
    fi
else
    print_status "System is already up to date"
fi
echo

# ============================================================================
# SECTION 2: Docker Installation Check
# ============================================================================
print_section "Verifying Docker installation..."

if ! command -v docker > /dev/null 2>&1; then
    print_warning "Docker is not installed. Installing Docker..."
    
    # Install prerequisites
    print_status "Installing prerequisites..."
    apt-get install -y ca-certificates curl gnupg lsb-release
    
    # Add Docker's official GPG key
    print_status "Adding Docker GPG key..."
    install -m 0755 -d /etc/apt/keyrings
    curl -fsSL https://download.docker.com/linux/ubuntu/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg
    chmod a+r /etc/apt/keyrings/docker.gpg
    
    # Set up the repository
    print_status "Adding Docker repository..."
    echo \
      "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
      $(lsb_release -cs) stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null
    
    # Update apt and install Docker
    print_status "Installing Docker Engine..."
    apt-get update
    if apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin; then
        print_status "Docker installed successfully"
    else
        print_error "Failed to install Docker"
        exit 1
    fi
else
    print_status "Docker is already installed ($(docker --version))"
fi

# Enable and start Docker service
print_status "Ensuring Docker service is enabled and running..."
systemctl enable docker
systemctl start docker

# Verify Docker daemon is running
if docker ps > /dev/null 2>&1; then
    print_status "Docker daemon is running"
else
    print_error "Docker daemon is not running properly"
    exit 1
fi
echo

# ============================================================================
# SECTION 3: Docker Group Setup
# ============================================================================
print_section "Setting up Docker group and permissions..."

# Check if docker group exists
if ! getent group docker > /dev/null 2>&1; then
    print_warning "Docker group does not exist. Creating it..."
    if groupadd docker; then
        print_status "Docker group created successfully"
    else
        print_error "Failed to create docker group"
        exit 1
    fi
else
    print_status "Docker group already exists"
fi

# Check if the original user is in the docker group
if ! groups "$ORIGINAL_USER" | grep -q docker; then
    print_status "Adding user $ORIGINAL_USER to docker group..."
    if usermod -aG docker "$ORIGINAL_USER"; then
        print_status "User added to docker group successfully"
        print_warning "Note: User $ORIGINAL_USER will need to log out and back in for group changes to take effect"
        print_warning "Or run: newgrp docker"
    else
        print_error "Failed to add user to docker group"
        exit 1
    fi
else
    print_status "User $ORIGINAL_USER is already in docker group"
fi
echo

# ============================================================================
# SECTION 4: Docker Compose Installation
# ============================================================================
print_section "Checking Docker Compose installation..."

# Check if docker compose is available (V2 plugin style)
if docker compose version > /dev/null 2>&1; then
    COMPOSE_VERSION=$(docker compose version --short 2>/dev/null || echo "unknown")
    print_status "Docker Compose is already installed (version: $COMPOSE_VERSION)"
# Also check for old standalone docker-compose
elif command -v docker-compose > /dev/null 2>&1; then
    COMPOSE_VERSION=$(docker-compose version --short 2>/dev/null || echo "unknown")
    print_status "Docker Compose (standalone) is installed (version: $COMPOSE_VERSION)"
    print_warning "Consider upgrading to Docker Compose V2 (plugin)"
else
    print_warning "Docker Compose not found. Installing..."
    
    # Install Docker Compose plugin (V2)
    print_status "Installing docker-compose-plugin..."
    if apt-get install -y docker-compose-plugin; then
        print_status "Docker Compose plugin installed successfully"
        
        # Verify installation
        if docker compose version > /dev/null 2>&1; then
            COMPOSE_VERSION=$(docker compose version --short 2>/dev/null || echo "unknown")
            print_status "Docker Compose version $COMPOSE_VERSION is now available"
        else
            print_error "Docker Compose installation verification failed"
            exit 1
        fi
    else
        print_error "Failed to install Docker Compose plugin"
        exit 1
    fi
fi
echo

# ============================================================================
# SECTION 5: GitHub CLI Installation
# ============================================================================
print_section "Checking GitHub CLI installation..."

if command -v gh > /dev/null 2>&1; then
    GH_VERSION=$(gh --version | head -n1 | awk '{print $3}')
    print_status "GitHub CLI is already installed (version: $GH_VERSION)"
else
    print_warning "GitHub CLI not found. Installing..."
    
    # Add GitHub CLI repository
    print_status "Adding GitHub CLI repository..."
    
    # Install prerequisites
    apt-get install -y curl gpg
    
    # Add GPG key
    curl -fsSL https://cli.github.com/packages/githubcli-archive-keyring.gpg | gpg --dearmor -o /usr/share/keyrings/githubcli-archive-keyring.gpg
    
    # Add repository
    echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/githubcli-archive-keyring.gpg] https://cli.github.com/packages stable main" | tee /etc/apt/sources.list.d/github-cli.list > /dev/null
    
    # Update and install
    print_status "Installing GitHub CLI..."
    apt-get update
    if apt-get install -y gh; then
        GH_VERSION=$(gh --version | head -n1 | awk '{print $3}')
        print_status "GitHub CLI version $GH_VERSION installed successfully"
    else
        print_error "Failed to install GitHub CLI"
        exit 1
    fi
fi
echo

# ============================================================================
# SECTION 6: Container Directory Setup
# ============================================================================
print_section "Setting up /srv/containers/ directory..."

# Create the directory if it doesn't exist
if [[ ! -d "/srv/containers" ]]; then
    print_status "Creating directory /srv/containers/"
    if mkdir -p /srv/containers; then
        print_status "Directory created successfully"
    else
        print_error "Failed to create directory"
        exit 1
    fi
else
    print_status "Directory /srv/containers/ already exists"
fi

# Set ownership to root:docker
print_status "Setting ownership to root:docker"
if chown root:docker /srv/containers; then
    print_status "Ownership set successfully"
else
    print_error "Failed to set ownership"
    exit 1
fi

# Set permissions: owner (root) has full access, group (docker) has read/write, others have no access
print_status "Setting permissions (rwxrwx---)"
if chmod 770 /srv/containers; then
    print_status "Permissions set successfully"
else
    print_error "Failed to set permissions"
    exit 1
fi

# Install ACL if needed
if ! command -v setfacl > /dev/null 2>&1; then
    print_status "Installing ACL package..."
    apt-get install -y acl > /dev/null 2>&1
fi

# Set default ACL for future files and directories
if command -v setfacl > /dev/null 2>&1; then
    print_status "Setting default ACL for future contents"
    if setfacl -d -m g:docker:rwx /srv/containers && setfacl -m g:docker:rwx /srv/containers; then
        print_status "ACL set successfully"
    else
        print_warning "Failed to set ACL"
    fi
else
    print_warning "ACL tools not available. Future files may not inherit proper permissions"
fi
echo

# ============================================================================
# SECTION 7: Verification and Summary
# ============================================================================
print_section "Setup Summary"

echo "Directory details:"
ls -lad /srv/containers 2>/dev/null || print_warning "Could not list directory details"
echo

if command -v getfacl > /dev/null 2>&1; then
    echo "ACL details:"
    getfacl /srv/containers 2>/dev/null || print_warning "Could not display ACL details"
    echo
fi

# Test Docker access for original user
print_status "Testing Docker access for $ORIGINAL_USER..."
if sudo -u "$ORIGINAL_USER" docker ps > /dev/null 2>&1; then
    print_status "✓ Docker access working (group change already effective)"
else
    print_warning "Docker access requires logout/login or 'newgrp docker'"
fi
echo

print_status "✓ System packages updated"
print_status "✓ Docker installed and verified"
print_status "✓ Docker Compose installed and verified"
print_status "✓ GitHub CLI installed and verified"
print_status "✓ Docker group configured"
print_status "✓ User $ORIGINAL_USER added to docker group"
print_status "✓ /srv/containers/ directory created with proper permissions"
echo

# Final instructions
print_section "IMPORTANT: Next Steps"
print_warning "To use Docker without sudo, $ORIGINAL_USER needs the docker group to be active."
print_warning "Since we just added you to the docker group, you need to either:"
echo "  1. Log out and back in to your SSH session, OR"
echo "  2. Run: newgrp docker (in current session)"
echo
print_status "After re-logging or running 'newgrp docker', test with:"
echo "  • docker --version"
echo "  • docker compose version"
echo "  • docker ps"
echo "  • gh --version"
echo
print_status "Setup completed successfully at $(date)!"