# The serverless track: scale-to-zero services and an on-demand pipeline driver.
# Idle cost is storage only; see docs/cloud.md.

resource "google_cloud_run_v2_service" "api" {
  name                = "rarelens-api"
  location            = var.region
  deletion_protection = false
  ingress             = "INGRESS_TRAFFIC_ALL"

  template {
    service_account = google_service_account.api.email
    scaling {
      min_instance_count = 0 # nothing runs, and nothing is billed, between visits
      max_instance_count = var.max_instances
    }
    containers {
      image = "${local.registry}/api:${var.image_tag}"
      ports { container_port = 8000 }
      resources {
        limits            = { cpu = "1", memory = "1Gi" }
        cpu_idle          = true # bill CPU only while a request is in flight
        startup_cpu_boost = true
      }
      env {
        name = "DATABASE_URL"
        value_source {
          secret_key_ref {
            secret  = google_secret_manager_secret.api_database_url.secret_id
            version = "latest"
          }
        }
      }
      env {
        name  = "CLOUDRUN_JOB"
        value = google_cloud_run_v2_job.nextflow.name
      }
      env {
        name  = "GCP_PROJECT"
        value = var.project
      }
      env {
        name  = "GCP_REGION"
        value = var.region
      }
      env {
        name  = "GCS_BUCKET"
        value = google_storage_bucket.data.name
      }
      env {
        name  = "MODEL_URI"
        value = var.model_uri
      }
    }
  }
  depends_on = [google_secret_manager_secret_version.api_database_url]
}

resource "google_cloud_run_v2_service" "web" {
  name                = "rarelens-web"
  location            = var.region
  deletion_protection = false
  ingress             = "INGRESS_TRAFFIC_ALL"

  template {
    scaling {
      min_instance_count = 0
      max_instance_count = var.max_instances
    }
    containers {
      image = "${local.registry}/web:${var.image_tag}"
      ports { container_port = 3000 }
      resources {
        limits            = { cpu = "1", memory = "512Mi" }
        cpu_idle          = true
        startup_cpu_boost = true
      }
      # The browser calls /api on this origin; src/routes/api/[...path] forwards it, so there is
      # one public URL and no CORS, exactly as the ingress arranges in the Kubernetes track.
      env {
        name  = "PUBLIC_API_URL"
        value = "/api"
      }
      env {
        name  = "API_INTERNAL_URL"
        value = google_cloud_run_v2_service.api.uri
      }
      # adapter-node sits behind Cloud Run's proxy; derive the origin from the forwarded headers.
      env {
        name  = "PROTOCOL_HEADER"
        value = "x-forwarded-proto"
      }
      env {
        name  = "HOST_HEADER"
        value = "x-forwarded-host"
      }
    }
  }
}

# The Nextflow driver. Started per annotation by the API (overriding the container args); the
# pipeline's own tasks then run on Google Batch (the gcp profile in pipeline/nextflow.config).
resource "google_cloud_run_v2_job" "nextflow" {
  name                = "rarelens-nextflow"
  location            = var.region
  deletion_protection = false

  template {
    task_count = 1
    template {
      service_account = google_service_account.pipeline.email
      max_retries     = 0
      timeout         = "7200s"
      containers {
        image = "${local.registry}/pipeline:${var.image_tag}"
        args  = ["-version"] # replaced on every execution by the API's overrides
        resources {
          limits = { cpu = "1", memory = "2Gi" }
        }
        env {
          name  = "GCP_PROJECT"
          value = var.project
        }
        env {
          name  = "GCP_REGION"
          value = var.region
        }
        env {
          name  = "GCS_BUCKET"
          value = google_storage_bucket.data.name
        }
        env {
          name  = "NXF_ANSI_LOG"
          value = "false"
        }
      }
    }
  }
}

# Anyone can open the UI and the API. There is no authentication by design (docs/architecture.md);
# max_instances and a billing budget are what bound the cost.
resource "google_cloud_run_v2_service_iam_member" "web_public" {
  project  = var.project
  location = google_cloud_run_v2_service.web.location
  name     = google_cloud_run_v2_service.web.name
  role     = "roles/run.invoker"
  member   = "allUsers"
}

resource "google_cloud_run_v2_service_iam_member" "api_public" {
  project  = var.project
  location = google_cloud_run_v2_service.api.location
  name     = google_cloud_run_v2_service.api.name
  role     = "roles/run.invoker"
  member   = "allUsers"
}

# Least privilege: the API may execute this one job with argument overrides, nothing more.
resource "google_cloud_run_v2_job_iam_member" "api_runs_nextflow" {
  project  = var.project
  location = google_cloud_run_v2_job.nextflow.location
  name     = google_cloud_run_v2_job.nextflow.name
  role     = "roles/run.jobsExecutorWithOverrides"
  member   = "serviceAccount:${google_service_account.api.email}"
}

resource "google_secret_manager_secret_iam_member" "api_database_url" {
  secret_id = google_secret_manager_secret.api_database_url.secret_id
  role      = "roles/secretmanager.secretAccessor"
  member    = "serviceAccount:${google_service_account.api.email}"
}

# Reading the model artifact from gs://<bucket>/models/... when MODEL_URI is set.
resource "google_storage_bucket_iam_member" "api_reads_data" {
  bucket = google_storage_bucket.data.name
  role   = "roles/storage.objectViewer"
  member = "serviceAccount:${google_service_account.api.email}"
}