#!/bin/bash
# Failback to Primary Region Script for Gravl
set -euo pipefail

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

log_info() { echo -e "${BLUE}[$(date '+%Y-%m-%d %H:%M:%S')]${NC} INFO: $*" >&2; }
log_success() { echo -e "${GREEN}[$(date '+%Y-%m-%d %H:%M:%S')]${NC} SUCCESS: $*" >&2; }
log_warn() { echo -e "${YELLOW}[$(date '+%Y-%m-%d %H:%M:%S')]${NC} WARN: $*" >&2; }
log_error() { echo -e "${RED}[$(date '+%Y-%m-%d %H:%M:%S')]${NC} ERROR: $*" >&2; }

PRIMARY_REGION="eu-north-1"
SECONDARY_REGION="us-east-1"
PRIMARY_NAMESPACE="gravl-prod"
SECONDARY_NAMESPACE="gravl-prod"
BACKUP_FILE=""
DRY_RUN=false

print_help() {
    cat << 'HELP'
Failback to Primary Region Script

Usage: ./failback.sh [OPTIONS]

Options:
  --backup-file FILE  Backup to restore from (default: latest)
  --dry-run           Show what would be done without doing it
  --confirm           Skip confirmation prompt
  --help              Show this help message

HELP
}

parse_args() {
    while [[ $# -gt 0 ]]; do
        case $1 in
            --backup-file) BACKUP_FILE="$2"; shift 2 ;;
            --dry-run) DRY_RUN=true; shift ;;
            --confirm) CONFIRM=true; shift ;;
            --help) print_help; exit 0 ;;
            *) log_error "Unknown option: $1"; exit 1 ;;
        esac
    done
}

confirm_failback() {
    log_warn "FAILBACK OPERATION - CRITICAL ACTION"
    log_warn "Primary Region: $PRIMARY_REGION"
    log_warn "Secondary Region: $SECONDARY_REGION"
    echo ""
    read -p "Type 'failback-confirm' to proceed: " confirmation
    if [ "$confirmation" != "failback-confirm" ]; then
        log_error "Failback cancelled"
        exit 1
    fi
}

backup_secondary() {
    log_info "Backing up current secondary before failback..."
    
    if [ "$DRY_RUN" = true ]; then
        log_info "[DRY RUN] Would backup secondary"
        return 0
    fi
    
    # Call backup script on secondary
    # /workspace/gravl/scripts/backup.sh --region us-east-1
    
    log_success "Secondary backed up"
}

restore_primary() {
    log_info "Restoring primary from backup..."
    
    if [ "$DRY_RUN" = true ]; then
        log_info "[DRY RUN] Would restore primary"
        return 0
    fi
    
    # /workspace/gravl/scripts/restore.sh --backup-file "$BACKUP_FILE" --validate
    
    log_success "Primary restored"
}

resync_secondary() {
    log_info "Setting secondary as replica of primary..."
    
    if [ "$DRY_RUN" = true ]; then
        log_info "[DRY RUN] Would resync secondary"
        return 0
    fi
    
    # kubectl exec gravl-db-0 -n gravl-prod --kubeconfig=$SECONDARY_KUBECONFIG -- \
    #   pg_basebackup -h gravl-db.gravl-prod.eu-north-1.svc.cluster.local \
    #   -D /var/lib/postgresql/data/pgdata -U gravl_replication
    
    log_success "Secondary resynchronized"
}

update_dns_to_primary() {
    log_info "Updating DNS to point to primary..."
    
    if [ "$DRY_RUN" = true ]; then
        log_info "[DRY RUN] Would update DNS"
        return 0
    fi
    
    # aws route53 change-resource-record-sets ...
    
    log_success "DNS updated to primary"
}

restart_applications() {
    log_info "Restarting applications..."
    
    if [ "$DRY_RUN" = true ]; then
        log_info "[DRY RUN] Would restart applications"
        return 0
    fi
    
    # kubectl rollout restart deployment/gravl-backend -n gravl-prod
    # kubectl rollout restart deployment/gravl-frontend -n gravl-prod
    
    log_success "Applications restarted"
}

main() {
    log_info "=========================================="
    log_info "Gravl Database Failback Script"
    log_info "=========================================="
    
    parse_args "$@"
    confirm_failback
    backup_secondary
    restore_primary
    resync_secondary
    update_dns_to_primary
    restart_applications
    
    log_success "Failback completed! Primary is active again."
}

main "$@"