// Grafana Alloy Configuration
// Sostituisce: Promtail + Node Exporter + OTEL Collector

// ============================================================================
// LOGGING - Raccolta log dai container Docker (sostituisce Promtail)
// ============================================================================

// Scopri container Docker con label logging=promtail
discovery.docker "containers" {
  host = "unix:///var/run/docker.sock"

  filter {
    name   = "label"
    values = ["logging=promtail"]
  }

  refresh_interval = "5s"
}

// Scrape log dai container scoperti
loki.source.docker "containers" {
  host       = "unix:///var/run/docker.sock"
  targets    = discovery.docker.containers.targets
  forward_to = [loki.relabel.docker.receiver]
}

// Relabeling per aggiungere label ai log
loki.relabel "docker" {
  forward_to = [loki.write.default.receiver]

  rule {
    source_labels = ["__meta_docker_container_name"]
    regex         = "/(.*)"
    target_label  = "container"
  }

  rule {
    source_labels = ["__meta_docker_container_label_logging_jobname"]
    target_label  = "job"
  }
}

// Scrivi i log a Loki
loki.write "default" {
  endpoint {
    url = "http://loki:3100/loki/api/v1/push"
  }

  external_labels = {
    environment = "production",
    cluster     = "myapp-cluster",
  }
}

// ============================================================================
// METRICS - Metriche sistema host (sostituisce Node Exporter)
// ============================================================================

// Scraping metriche locali dell'host
prometheus.exporter.unix "host" {
  // Raccoglie metriche del sistema operativo
  set_collectors = [
    "cpu",
    "loadavg",
    "meminfo",
    "netdev",
    "diskstats",
    "filesystem",
    "uname",
    "time",
  ]
}

// Scrape delle metriche raccolte
prometheus.scrape "host_metrics" {
  targets    = prometheus.exporter.unix.host.targets
  forward_to = [prometheus.remote_write.default.receiver]

  scrape_interval = "10s"

  clustering {
    enabled = false
  }
}

// Scraping self-monitoring di Alloy
prometheus.scrape "alloy_metrics" {
  targets = [{
    __address__ = "localhost:12345",
  }]
  forward_to = [prometheus.remote_write.default.receiver]

  scrape_interval = "10s"
}

// ============================================================================
// TRACES - Ricezione traces OTLP (sostituisce OTEL Collector)
// ============================================================================

// Ricevi traces via OTLP gRPC
otelcol.receiver.otlp "default" {
  grpc {
    endpoint = "0.0.0.0:4317"
  }

  http {
    endpoint = "0.0.0.0:4318"
  }

  output {
    metrics = [otelcol.processor.batch.default.input]
    logs    = [otelcol.processor.batch.default.input]
    traces  = [otelcol.processor.batch.default.input]
  }
}

// Batch processor per ottimizzare l'invio
otelcol.processor.batch "default" {
  timeout              = "10s"
  send_batch_size      = 10000
  send_batch_max_size  = 11000

  output {
    metrics = [otelcol.exporter.prometheus.default.input]
    traces  = [otelcol.exporter.otlp.tempo.input]
    logs    = [otelcol.exporter.loki.default.input]
  }
}

// Esporta metriche OTLP a Prometheus
otelcol.exporter.prometheus "default" {
  forward_to = [prometheus.remote_write.default.receiver]
}

// Esporta traces a Tempo
otelcol.exporter.otlp "tempo" {
  client {
    endpoint = "tempo:4317"
    tls {
      insecure = true
    }
  }
}

// Esporta log OTLP a Loki
otelcol.exporter.loki "default" {
  forward_to = [loki.write.default.receiver]
}

// ============================================================================
// REMOTE WRITE - Invia metriche a Prometheus
// ============================================================================

prometheus.remote_write "default" {
  endpoint {
    url = "http://prometheus:9090/api/v1/write"

    metadata_config {
      send_interval = "1m"
    }

    queue_config {
      capacity          = 10000
      max_shards        = 10
      min_shards        = 1
      max_samples_per_send = 5000
    }
  }
}