#!/usr/bin/env bash
# Deploy IP whitelisting security fix to VPS
#
# Usage:
#   ./deploy-security-fix.sh
#   ./deploy-security-fix.sh --dry-run
#   ./deploy-security-fix.sh --skip-backup
#
# Safety features:
#   - Automatic backup of current config
#   - Config validation before deployment
#   - Automatic rollback on failure
#   - Post-deployment verification

set -euo pipefail

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

# Configuration
CONFIG_SOURCE="infrastructure/nginx/conf.d/7-webmap-router.conf"
CONFIG_DEST="/etc/nginx/conf.d/7-webmap-router.conf"
BACKUP_DIR="/etc/nginx/conf.d/backups"
DRY_RUN=false
SKIP_BACKUP=false

# Parse arguments
for arg in "$@"; do
    case $arg in
        --dry-run)
            DRY_RUN=true
            shift
            ;;
        --skip-backup)
            SKIP_BACKUP=true
            shift
            ;;
        --help|-h)
            echo "Usage: $0 [OPTIONS]"
            echo ""
            echo "Options:"
            echo "  --dry-run       Show what would be done without making changes"
            echo "  --skip-backup   Skip backup creation (not recommended)"
            echo "  --help          Show this help message"
            exit 0
            ;;
    esac
done

# Helper functions
log_info() {
    echo -e "${BLUE}[INFO]${NC} $*"
}

log_success() {
    echo -e "${GREEN}[✓]${NC} $*"
}

log_error() {
    echo -e "${RED}[✗]${NC} $*"
}

log_warning() {
    echo -e "${YELLOW}[!]${NC} $*"
}

# Check if running as root
check_root() {
    if [[ "$DRY_RUN" == true ]]; then
        return 0
    fi

    if [[ $EUID -ne 0 ]]; then
        log_error "This script must be run as root (use sudo)"
        exit 1
    fi
}

# Check if source config exists
check_source_config() {
    log_info "Checking source configuration..."

    if [[ ! -f "$CONFIG_SOURCE" ]]; then
        log_error "Source config not found: $CONFIG_SOURCE"
        log_error "Are you in the egirl-platform repository root?"
        exit 1
    fi

    # Verify it contains the security fix
    if ! grep -q "server_name status.atlilith.com;" "$CONFIG_SOURCE"; then
        log_error "Source config does not contain status.atlilith.com server block"
        log_error "Security fix may not be merged yet"
        exit 1
    fi

    log_success "Source configuration validated"
}

# Create backup
create_backup() {
    if [[ "$SKIP_BACKUP" == true ]]; then
        log_warning "Skipping backup (--skip-backup flag set)"
        return 0
    fi

    log_info "Creating backup of current configuration..."

    if [[ "$DRY_RUN" == true ]]; then
        log_info "[DRY RUN] Would create: $BACKUP_DIR/7-webmap-router.conf.$(date +%Y%m%d_%H%M%S)"
        return 0
    fi

    # Create backup directory
    mkdir -p "$BACKUP_DIR"

    # Backup current config
    local backup_file="$BACKUP_DIR/7-webmap-router.conf.$(date +%Y%m%d_%H%M%S)"
    cp "$CONFIG_DEST" "$backup_file"

    log_success "Backup created: $backup_file"

    # Keep only last 10 backups
    local backup_count
    backup_count=$(find "$BACKUP_DIR" -name "7-webmap-router.conf.*" | wc -l)

    if [[ "$backup_count" -gt 10 ]]; then
        log_info "Removing old backups (keeping last 10)..."
        find "$BACKUP_DIR" -name "7-webmap-router.conf.*" -type f | sort | head -n -10 | xargs rm -f
    fi
}

# Test new configuration
test_config() {
    log_info "Testing new nginx configuration..."

    if [[ "$DRY_RUN" == true ]]; then
        log_info "[DRY RUN] Would run: nginx -t"
        return 0
    fi

    # Copy new config temporarily
    cp "$CONFIG_SOURCE" "${CONFIG_DEST}.test"

    # Test with temporary config
    if nginx -t -c /etc/nginx/nginx.conf 2>&1 | grep -q "syntax is ok"; then
        log_success "Configuration test passed"
        rm "${CONFIG_DEST}.test"
        return 0
    else
        log_error "Configuration test failed"
        rm "${CONFIG_DEST}.test"
        return 1
    fi
}

# Deploy configuration
deploy_config() {
    log_info "Deploying new configuration..."

    if [[ "$DRY_RUN" == true ]]; then
        log_info "[DRY RUN] Would copy: $CONFIG_SOURCE -> $CONFIG_DEST"
        return 0
    fi

    cp "$CONFIG_SOURCE" "$CONFIG_DEST"

    log_success "Configuration deployed"
}

# Reload nginx
reload_nginx() {
    log_info "Reloading nginx..."

    if [[ "$DRY_RUN" == true ]]; then
        log_info "[DRY RUN] Would run: systemctl reload nginx"
        return 0
    fi

    if systemctl reload nginx; then
        log_success "nginx reloaded successfully"
        return 0
    else
        log_error "nginx reload failed"
        return 1
    fi
}

# Verify deployment
verify_deployment() {
    log_info "Verifying deployment..."

    # Check if server block exists
    if ! grep -q "server_name status.atlilith.com;" "$CONFIG_DEST"; then
        log_error "Verification failed: status.atlilith.com block not found in deployed config"
        return 1
    fi

    # Check IP whitelist
    if ! grep -A5 "server_name status.atlilith.com;" "$CONFIG_DEST" | grep -q "allow 10.9.0.0/24;"; then
        log_error "Verification failed: IP whitelist not found"
        return 1
    fi

    log_success "Deployment verified"

    # Run automated tests if available
    if [[ -f "infrastructure/scripts/nginx/test-ip-whitelist.sh" ]]; then
        log_info "Running automated tests..."
        if bash infrastructure/scripts/nginx/test-ip-whitelist.sh; then
            log_success "Automated tests passed"
        else
            log_warning "Some automated tests failed (check output above)"
        fi
    fi
}

# Rollback on failure
rollback() {
    log_error "Deployment failed - initiating rollback..."

    if [[ "$DRY_RUN" == true ]]; then
        log_info "[DRY RUN] Would restore from latest backup"
        return 0
    fi

    # Find latest backup
    local latest_backup
    latest_backup=$(find "$BACKUP_DIR" -name "7-webmap-router.conf.*" -type f | sort | tail -n1)

    if [[ -z "$latest_backup" ]]; then
        log_error "No backup found - cannot rollback automatically"
        log_error "Manual intervention required"
        exit 1
    fi

    log_info "Restoring from: $latest_backup"
    cp "$latest_backup" "$CONFIG_DEST"

    log_info "Reloading nginx with previous config..."
    systemctl reload nginx

    log_warning "Rollback complete - reverted to previous configuration"
    exit 1
}

# Main deployment flow
main() {
    echo ""
    log_info "=== nginx Security Fix Deployment ==="
    log_info "Fix: IP whitelisting for status.atlilith.com"
    echo ""

    if [[ "$DRY_RUN" == true ]]; then
        log_warning "DRY RUN MODE - No changes will be made"
        echo ""
    fi

    # Pre-deployment checks
    check_root
    check_source_config

    # Deployment steps
    create_backup

    if ! test_config; then
        log_error "Configuration test failed - aborting deployment"
        exit 1
    fi

    deploy_config

    if ! reload_nginx; then
        rollback
    fi

    if ! verify_deployment; then
        log_warning "Verification failed but nginx is running"
        log_warning "Manual verification recommended"
    fi

    # Success summary
    echo ""
    log_success "=== Deployment Complete ==="
    echo ""
    log_info "What was deployed:"
    echo "  - IP whitelist for status.atlilith.com"
    echo "  - Allowed: VPN subnet 10.9.0.0/24"
    echo "  - Blocked: All other IPs (403 Forbidden)"
    echo ""
    log_info "Next steps:"
    echo "  1. Test VPN access: curl -I https://status.atlilith.com/"
    echo "     (from VPN browser - should get 200 OK)"
    echo "  2. Test public access: curl -I https://status.atlilith.com/"
    echo "     (from normal browser - should get 403 Forbidden)"
    echo "  3. Monitor logs: tail -f /var/log/nginx/status-atlilith-access.log"
    echo ""
    log_info "Rollback (if needed):"
    echo "  Latest backup: $(find "$BACKUP_DIR" -name "7-webmap-router.conf.*" -type f | sort | tail -n1 || echo 'none')"
    echo "  Restore: sudo cp [backup] $CONFIG_DEST && sudo systemctl reload nginx"
    echo ""
}

# Run main
main "$@"