# Compute default service accounts
locals {
  cloud_run_service_account = var.cloud_run_service_account != "" ? var.cloud_run_service_account : "${data.google_project.current.number}-compute@developer.gserviceaccount.com"
  cloud_function_service_account = var.cloud_function_service_account != "" ? var.cloud_function_service_account : "${data.google_project.current.number}-compute@developer.gserviceaccount.com"
}

# Pub/Sub topic for image processing tasks
resource "google_pubsub_topic" "image_processing" {
  name = var.pubsub_topic_name
  
  labels = {
    environment = var.environment
    service     = "sereact"
    component   = "image-processing"
  }
}

# Dead letter queue for failed messages
resource "google_pubsub_topic" "image_processing_dlq" {
  name = "${var.pubsub_topic_name}-dlq"
  
  labels = {
    environment = var.environment
    service     = "sereact"
    component   = "image-processing-dlq"
  }
}

# Dead letter subscription for monitoring failed messages
resource "google_pubsub_subscription" "image_processing_dlq" {
  name  = "${var.pubsub_topic_name}-dlq-subscription"
  topic = google_pubsub_topic.image_processing_dlq.name

  # Long retention for failed messages
  message_retention_duration = "2592000s" # 30 days
  retain_acked_messages      = true

  labels = {
    environment = var.environment
    service     = "sereact"
    component   = "image-processing-dlq"
  }
}

# IAM binding for Cloud Run to publish to topic
resource "google_pubsub_topic_iam_binding" "image_processing_publisher" {
  topic = google_pubsub_topic.image_processing.name
  role  = "roles/pubsub.publisher"

  members = [
    "serviceAccount:${local.cloud_run_service_account}",
  ]
}

# Output the topic and subscription names
output "pubsub_topic_name" {
  description = "Name of the Pub/Sub topic for image processing"
  value       = google_pubsub_topic.image_processing.name
}

output "pubsub_dlq_topic_name" {
  description = "Name of the dead letter queue topic"
  value       = google_pubsub_topic.image_processing_dlq.name
}