#!/bin/bash
#
# Business Central Backup System - Setup Script
# Installs dependencies and configures the backup environment
#

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
CONFIG_FILE="${SCRIPT_DIR}/bc-backup.conf"
TEMPLATE_FILE="${SCRIPT_DIR}/bc-backup.conf.template"

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

echo_info() {
    echo -e "${BLUE}[INFO]${NC} $*"
}

echo_success() {
    echo -e "${GREEN}[SUCCESS]${NC} $*"
}

echo_warn() {
    echo -e "${YELLOW}[WARN]${NC} $*"
}

echo_error() {
    echo -e "${RED}[ERROR]${NC} $*"
}

check_command() {
    if command -v "$1" &> /dev/null; then
        echo_success "$1 is installed"
        return 0
    else
        echo_warn "$1 is NOT installed"
        return 1
    fi
}

echo_info "========================================="
echo_info "Business Central Backup System Setup"
echo_info "========================================="
echo ""

# Detect OS
if [[ -f /etc/os-release ]]; then
    . /etc/os-release
    OS=$ID
    VER=$VERSION_ID
    echo_info "Detected OS: $PRETTY_NAME"
else
    echo_error "Cannot detect OS"
    exit 1
fi

# Check if running as root
if [[ $EUID -eq 0 ]]; then
    echo_warn "Running as root. Dependencies will be installed system-wide."
    SUDO=""
else
    echo_info "Running as regular user. May prompt for sudo password."
    SUDO="sudo"
fi

echo ""
echo_info "=== Checking Dependencies ==="
echo ""

# Track what needs to be installed
MISSING_DEPS=()

# Check PowerShell
echo_info "Checking PowerShell..."
if ! check_command pwsh; then
    MISSING_DEPS+=("pwsh")
fi

# Check GPG
echo_info "Checking GPG..."
if ! check_command gpg; then
    MISSING_DEPS+=("gpg")
fi

# Check AWS CLI
echo_info "Checking AWS CLI..."
if ! check_command aws; then
    MISSING_DEPS+=("awscli")
fi

# Check curl and wget
echo_info "Checking curl..."
check_command curl || MISSING_DEPS+=("curl")

echo_info "Checking wget..."
check_command wget || MISSING_DEPS+=("wget")

# Check jq (useful for debugging)
echo_info "Checking jq (optional)..."
check_command jq || echo_warn "jq not installed (optional, useful for JSON parsing)"

# Install missing dependencies
if [[ ${#MISSING_DEPS[@]} -gt 0 ]]; then
    echo ""
    echo_warn "Missing dependencies: ${MISSING_DEPS[*]}"
    echo ""
    read -p "Install missing dependencies? (y/n) " -n 1 -r
    echo
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        for dep in "${MISSING_DEPS[@]}"; do
            echo_info "Installing $dep..."

            case $dep in
                pwsh)
                    # Install PowerShell
                    case $OS in
                        ubuntu|debian)
                            # Download Microsoft repository GPG keys
                            wget -q "https://packages.microsoft.com/config/$OS/$VER/packages-microsoft-prod.deb" -O /tmp/packages-microsoft-prod.deb
                            $SUDO dpkg -i /tmp/packages-microsoft-prod.deb
                            rm /tmp/packages-microsoft-prod.deb
                            $SUDO apt-get update
                            $SUDO apt-get install -y powershell
                            ;;
                        centos|rhel|fedora)
                            $SUDO rpm --import https://packages.microsoft.com/keys/microsoft.asc
                            curl -o /tmp/packages-microsoft-prod.rpm "https://packages.microsoft.com/config/$OS/$VER/packages-microsoft-prod.rpm"
                            $SUDO rpm -i /tmp/packages-microsoft-prod.rpm
                            rm /tmp/packages-microsoft-prod.rpm
                            $SUDO yum install -y powershell
                            ;;
                        *)
                            echo_error "Unsupported OS for automatic PowerShell installation"
                            echo_info "Please install PowerShell manually: https://docs.microsoft.com/en-us/powershell/scripting/install/installing-powershell-on-linux"
                            ;;
                    esac
                    ;;
                gpg)
                    # Install GPG
                    case $OS in
                        ubuntu|debian)
                            $SUDO apt-get update
                            $SUDO apt-get install -y gnupg
                            ;;
                        centos|rhel|fedora)
                            $SUDO yum install -y gnupg2
                            ;;
                        *)
                            echo_error "Unsupported OS for automatic GPG installation"
                            ;;
                    esac
                    ;;
                awscli)
                    # Install AWS CLI v2
                    echo_info "Installing AWS CLI v2..."
                    case $(uname -m) in
                        x86_64)
                            curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "/tmp/awscliv2.zip"
                            ;;
                        aarch64)
                            curl "https://awscli.amazonaws.com/awscli-exe-linux-aarch64.zip" -o "/tmp/awscliv2.zip"
                            ;;
                        *)
                            echo_error "Unsupported architecture for AWS CLI"
                            continue
                            ;;
                    esac
                    unzip -q /tmp/awscliv2.zip -d /tmp
                    $SUDO /tmp/aws/install
                    rm -rf /tmp/aws /tmp/awscliv2.zip
                    ;;
                curl)
                    case $OS in
                        ubuntu|debian)
                            $SUDO apt-get update
                            $SUDO apt-get install -y curl
                            ;;
                        centos|rhel|fedora)
                            $SUDO yum install -y curl
                            ;;
                    esac
                    ;;
                wget)
                    case $OS in
                        ubuntu|debian)
                            $SUDO apt-get update
                            $SUDO apt-get install -y wget
                            ;;
                        centos|rhel|fedora)
                            $SUDO yum install -y wget
                            ;;
                    esac
                    ;;
            esac
        done
    else
        echo_error "Cannot proceed without required dependencies"
        exit 1
    fi
fi

echo ""
echo_success "All required dependencies are installed"
echo ""

# Create directory structure
echo_info "=== Setting up directory structure ==="
mkdir -p "${SCRIPT_DIR}/logs"
mkdir -p "${SCRIPT_DIR}/temp"
echo_success "Created logs/ and temp/ directories"

# Set up configuration file
echo ""
echo_info "=== Configuration Setup ==="

if [[ -f "${CONFIG_FILE}" ]]; then
    echo_warn "Configuration file already exists: ${CONFIG_FILE}"
    read -p "Overwrite with template? (y/n) " -n 1 -r
    echo
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        cp "${TEMPLATE_FILE}" "${CONFIG_FILE}"
        echo_success "Configuration template copied to bc-backup.conf"
    fi
else
    cp "${TEMPLATE_FILE}" "${CONFIG_FILE}"
    echo_success "Configuration template copied to bc-backup.conf"
fi

# Make scripts executable
echo ""
echo_info "=== Setting permissions ==="
chmod +x "${SCRIPT_DIR}/bc-backup.sh"
chmod +x "${SCRIPT_DIR}/bc-export.ps1"
chmod 600 "${CONFIG_FILE}"  # Restrict config file permissions
echo_success "Scripts are now executable"
echo_success "Config file permissions set to 600 (owner read/write only)"

# Test AWS CLI configuration
echo ""
echo_info "=== Testing AWS CLI ==="
if [[ -f "${CONFIG_FILE}" ]]; then
    # Source config to test
    if grep -q 'AWS_ACCESS_KEY_ID=""' "${CONFIG_FILE}"; then
        echo_warn "AWS credentials not yet configured in bc-backup.conf"
    else
        echo_info "AWS CLI appears to be configured in bc-backup.conf"
    fi
fi

# S3 bucket object lock check
echo ""
echo_info "=== Important: S3 Object Lock Configuration ==="
echo_warn "Your S3 bucket MUST have Object Lock enabled for immutability"
echo_info "Object Lock can only be enabled when creating a bucket"
echo ""
echo_info "To create an S3 bucket with Object Lock (AWS example):"
echo "  aws s3api create-bucket --bucket YOUR-BUCKET-NAME \\"
echo "    --region YOUR-REGION \\"
echo "    --create-bucket-configuration LocationConstraint=YOUR-REGION \\"
echo "    --object-lock-enabled-for-bucket"
echo ""
echo_info "Then configure default retention:"
echo "  aws s3api put-object-lock-configuration --bucket YOUR-BUCKET-NAME \\"
echo "    --object-lock-configuration '{\"ObjectLockEnabled\":\"Enabled\",\"Rule\":{\"DefaultRetention\":{\"Mode\":\"COMPLIANCE\",\"Days\":30}}}'"
echo ""

# Setup cron job
echo ""
echo_info "=== Cron Job Setup ==="
echo_info "To run backups hourly, add this to your crontab:"
echo ""
echo "  0 * * * * ${SCRIPT_DIR}/bc-backup.sh >> ${SCRIPT_DIR}/logs/cron.log 2>&1"
echo ""
read -p "Add this cron job now? (y/n) " -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    CRON_CMD="0 * * * * ${SCRIPT_DIR}/bc-backup.sh >> ${SCRIPT_DIR}/logs/cron.log 2>&1"
    (crontab -l 2>/dev/null | grep -v "${SCRIPT_DIR}/bc-backup.sh"; echo "$CRON_CMD") | crontab -
    echo_success "Cron job added successfully"
    echo_info "View your crontab with: crontab -l"
else
    echo_info "Skipped cron job setup. You can add it manually later."
fi

# Final instructions
echo ""
echo_info "========================================="
echo_success "Setup completed successfully!"
echo_info "========================================="
echo ""
echo_info "Next steps:"
echo ""
echo "1. Edit configuration file:"
echo "   nano ${CONFIG_FILE}"
echo ""
echo "2. Fill in the following required values:"
echo "   - AZURE_TENANT_ID, AZURE_CLIENT_ID, AZURE_CLIENT_SECRET"
echo "   - BC_ENVIRONMENT_NAME"
echo "   - ENCRYPTION_PASSPHRASE (generate with: openssl rand -base64 32)"
echo "   - S3_BUCKET, S3_ENDPOINT"
echo "   - AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY"
echo ""
echo "3. Test the backup manually:"
echo "   ${SCRIPT_DIR}/bc-backup.sh"
echo ""
echo "4. Check logs for any issues:"
echo "   tail -f ${SCRIPT_DIR}/logs/backup.log"
echo ""
echo_warn "IMPORTANT: Store your ENCRYPTION_PASSPHRASE securely!"
echo_warn "Without it, you cannot decrypt your backups."
echo ""