#!/bin/bash

# Cloud Hypervisor Installation Script
# Downloads and installs Cloud Hypervisor from GitHub releases
# Compatible with Ubuntu/Debian systems

set -e

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

# Cloud Hypervisor configuration
CH_VERSION="v46.0"
CH_URL="https://github.com/cloud-hypervisor/cloud-hypervisor/releases/download/${CH_VERSION}/cloud-hypervisor-static"
CH_BINARY="cloud-hypervisor"
MIN_SIZE_MB=4

log() {
    echo -e "${GREEN}[$(date +'%Y-%m-%d %H:%M:%S')] $1${NC}"
}

warn() {
    echo -e "${YELLOW}[$(date +'%Y-%m-%d %H:%M:%S')] WARNING: $1${NC}"
}

error() {
    echo -e "${RED}[$(date +'%Y-%m-%d %H:%M:%S')] ERROR: $1${NC}"
    exit 1
}

# Check if running as root
if [ "$EUID" -eq 0 ]; then
    log "Running as root. Cloud Hypervisor will be installed system-wide."
    INSTALL_DIR="/usr/local/bin"
else
    log "Installing Cloud Hypervisor for current user"
    INSTALL_DIR="$HOME/.local/bin"
    # Create local bin directory if it doesn't exist
    mkdir -p "$INSTALL_DIR"
fi

# Check if Cloud Hypervisor is already installed
if command -v cloud-hypervisor &> /dev/null; then
    CH_CURRENT_VERSION=$(cloud-hypervisor --version 2>/dev/null | head -n1 || echo "")
    if [ -n "$CH_CURRENT_VERSION" ]; then
        warn "Cloud Hypervisor is already installed: $CH_CURRENT_VERSION"
        read -p "Do you want to update/reinstall? (y/N): " -n 1 -r
        echo
        if [[ ! $REPLY =~ ^[Yy]$ ]]; then
            log "Installation cancelled"
            exit 0
        fi
    fi
fi

# Check for required dependencies
log "Checking system dependencies..."
MISSING_DEPS=()

# Check for curl
if ! command -v curl &> /dev/null; then
    MISSING_DEPS+=("curl")
fi

# Install missing dependencies
if [ ${#MISSING_DEPS[@]} -gt 0 ]; then
    log "Installing missing dependencies: ${MISSING_DEPS[*]}"
    if [ "$EUID" -eq 0 ]; then
        apt update
        apt install -y "${MISSING_DEPS[@]}"
    else
        log "Please install the following packages and run this script again:"
        log "sudo apt update && sudo apt install -y ${MISSING_DEPS[*]}"
        exit 1
    fi
fi

log "Starting Cloud Hypervisor installation..."
log "Version: $CH_VERSION"
log "Install directory: $INSTALL_DIR"

# Create temporary directory for download
TEMP_DIR=$(mktemp -d)
TEMP_FILE="$TEMP_DIR/$CH_BINARY"

# Cleanup function
cleanup() {
    rm -rf "$TEMP_DIR"
}
trap cleanup EXIT

log "Downloading Cloud Hypervisor from $CH_URL..."

# Download with size verification
if ! curl -L --fail --progress-bar -o "$TEMP_FILE" "$CH_URL"; then
    error "Failed to download Cloud Hypervisor from $CH_URL"
fi

# Check file size
FILE_SIZE=$(stat -c%s "$TEMP_FILE" 2>/dev/null || stat -f%z "$TEMP_FILE" 2>/dev/null || echo "0")
FILE_SIZE_MB=$((FILE_SIZE / 1024 / 1024))

log "Downloaded file size: ${FILE_SIZE_MB}MB"

if [ "$FILE_SIZE_MB" -lt "$MIN_SIZE_MB" ]; then
    error "Downloaded file is too small (${FILE_SIZE_MB}MB). Expected at least ${MIN_SIZE_MB}MB. Download may be corrupted."
fi

log "✅ Download size verification passed (${FILE_SIZE_MB}MB >= ${MIN_SIZE_MB}MB)"

# Make the binary executable
chmod +x "$TEMP_FILE"

# Test the binary before installation
log "Testing downloaded binary..."
if ! "$TEMP_FILE" --version &> /dev/null; then
    error "Downloaded binary is not working correctly"
fi

log "✅ Binary test passed"

# Install the binary
log "Installing Cloud Hypervisor to $INSTALL_DIR..."
if [ "$EUID" -eq 0 ]; then
    cp "$TEMP_FILE" "$INSTALL_DIR/$CH_BINARY"
else
    cp "$TEMP_FILE" "$INSTALL_DIR/$CH_BINARY"
    # Add to PATH if not already there
    if [[ ":$PATH:" != *":$INSTALL_DIR:"* ]]; then
        warn "Adding $INSTALL_DIR to PATH in ~/.bashrc"
        echo "export PATH=\"$INSTALL_DIR:\$PATH\"" >> ~/.bashrc
        export PATH="$INSTALL_DIR:$PATH"
    fi
fi

# Verify installation
log "Verifying Cloud Hypervisor installation..."

# Set PATH for verification
if [ "$EUID" -ne 0 ]; then
    export PATH="$INSTALL_DIR:$PATH"
fi

if command -v cloud-hypervisor &> /dev/null; then
    CH_VERSION_OUTPUT=$(cloud-hypervisor --version 2>/dev/null || echo "")
    if [ -n "$CH_VERSION_OUTPUT" ]; then
        log "✅ Cloud Hypervisor installation successful!"
        log "Version: $CH_VERSION_OUTPUT"
        log "Location: $(which cloud-hypervisor)"
        
        # Test basic functionality
        log "Testing basic functionality..."
        if cloud-hypervisor --help &> /dev/null; then
            log "✅ Basic functionality test passed"
        else
            warn "Basic functionality test failed, but binary is installed"
        fi
        
        log "✅ Cloud Hypervisor installation completed successfully!"
        log ""
        log "Next steps:"
        if [ "$EUID" -eq 0 ]; then
            log "- Cloud Hypervisor is available system-wide"
        else
            log "- Run 'source ~/.bashrc' to update PATH in this session"
            log "- Or restart your terminal"
        fi
        log "- Run 'cloud-hypervisor --help' to see available options"
        log "- Check the documentation at: https://github.com/cloud-hypervisor/cloud-hypervisor"
    else
        error "Cloud Hypervisor was installed but version check failed"
    fi
else
    error "Cloud Hypervisor installation failed. Binary not found in PATH."
fi