#!/bin/bash
# Setup script for database monitoring with OpenTelemetry and SigNoz
# This script creates monitoring users in PostgreSQL and deploys the collector

set -e

echo "========================================="
echo "Database Monitoring Setup for SigNoz"
echo "========================================="
echo ""

# Configuration
NAMESPACE="bakery-ia"
MONITOR_USER="otel_monitor"
MONITOR_PASSWORD=$(openssl rand -base64 32)

# PostgreSQL databases to monitor
DATABASES=(
  "auth-db-service:auth_db"
  "inventory-db-service:inventory_db"
  "orders-db-service:orders_db"
  "tenant-db-service:tenant_db"
  "sales-db-service:sales_db"
  "production-db-service:production_db"
  "recipes-db-service:recipes_db"
  "procurement-db-service:procurement_db"
  "distribution-db-service:distribution_db"
  "forecasting-db-service:forecasting_db"
  "external-db-service:external_db"
  "suppliers-db-service:suppliers_db"
  "pos-db-service:pos_db"
  "training-db-service:training_db"
  "notification-db-service:notification_db"
  "orchestrator-db-service:orchestrator_db"
  "ai-insights-db-service:ai_insights_db"
)

echo "Step 1: Creating monitoring user in PostgreSQL databases"
echo "========================================="
echo ""

for db_entry in "${DATABASES[@]}"; do
  IFS=':' read -r service dbname <<< "$db_entry"

  echo "Creating monitoring user in $dbname..."

  # Create monitoring user via kubectl exec
  kubectl exec -n "$NAMESPACE" "deployment/${service%-service}" -- psql -U postgres -d "$dbname" -c "
    DO \$\$
    BEGIN
      IF NOT EXISTS (SELECT FROM pg_catalog.pg_roles WHERE rolname = '$MONITOR_USER') THEN
        CREATE USER $MONITOR_USER WITH PASSWORD '$MONITOR_PASSWORD';
        GRANT pg_monitor TO $MONITOR_USER;
        GRANT CONNECT ON DATABASE $dbname TO $MONITOR_USER;
        RAISE NOTICE 'User $MONITOR_USER created successfully';
      ELSE
        RAISE NOTICE 'User $MONITOR_USER already exists';
      END IF;
    END
    \$\$;
  " 2>/dev/null || echo "  ⚠️  Warning: Could not create user in $dbname (may already exist or database not ready)"

  echo ""
done

echo "✅ Monitoring users created"
echo ""

echo "Step 2: Creating Kubernetes secret for monitoring credentials"
echo "========================================="
echo ""

# Create secret for database monitoring
kubectl create secret generic database-monitor-secrets \
  -n "$NAMESPACE" \
  --from-literal=POSTGRES_MONITOR_USER="$MONITOR_USER" \
  --from-literal=POSTGRES_MONITOR_PASSWORD="$MONITOR_PASSWORD" \
  --dry-run=client -o yaml | kubectl apply -f -

echo "✅ Secret created: database-monitor-secrets"
echo ""

echo "Step 3: Deploying OpenTelemetry collector for database monitoring"
echo "========================================="
echo ""

kubectl apply -f infrastructure/kubernetes/base/monitoring/database-otel-collector.yaml

echo "✅ Database monitoring collector deployed"
echo ""

echo "Step 4: Waiting for collector to be ready"
echo "========================================="
echo ""

kubectl wait --for=condition=available --timeout=60s \
  deployment/database-otel-collector -n "$NAMESPACE"

echo "✅ Collector is ready"
echo ""

echo "========================================="
echo "Database Monitoring Setup Complete!"
echo "========================================="
echo ""
echo "What's been configured:"
echo "  ✅ Monitoring user created in all PostgreSQL databases"
echo "  ✅ OpenTelemetry collector deployed for database metrics"
echo "  ✅ Metrics exported to SigNoz"
echo ""
echo "Metrics being collected:"
echo "  📊 PostgreSQL: connections, commits, rollbacks, deadlocks, table sizes"
echo "  📊 Redis: memory usage, keyspace hits/misses, connected clients"
echo "  📊 RabbitMQ: queue depth, message rates, consumer count"
echo ""
echo "Next steps:"
echo "  1. Check collector logs:"
echo "     kubectl logs -n $NAMESPACE deployment/database-otel-collector"
echo ""
echo "  2. View metrics in SigNoz:"
echo "     - Go to https://monitoring.bakery-ia.local"
echo "     - Create dashboard with queries like:"
echo "       * postgresql.backends (connections)"
echo "       * postgresql.database.size (database size)"
echo "       * redis.memory.used (Redis memory)"
echo "       * rabbitmq.message.current (queue depth)"
echo ""
echo "  3. Create alerts for:"
echo "     - High connection count (approaching max_connections)"
echo "     - Slow query detection (via application traces)"
echo "     - High Redis memory usage"
echo "     - RabbitMQ queue buildup"
echo ""