#!/bin/sh
# CI lint: every literal `"service.name"="<x>"` selector in a shipped grafana
# dashboard must name a service.name that something emits. A dashboard
# querying a name nobody sets renders empty panels with no error.
#
# `known` lists the emitted names, one `name|file|anchor` per line. The
# anchor is a fixed string that must still appear in that file, so an entry
# cannot outlive the code that sets the name. Regex selectors
# (`"service.name"=~"$service"`) are template variables and are not checked.
#
set -eu

dashboards_dir="nix/host-modules/swarm-grafana/dashboards"

# bao: `collectorServiceName` upserted on the store's collector.
# authelia, forgejo: `serviceName` of the journal forwarder in each module.
# swarm-controller: the resource of the controller's own metrics.
# otelcol-contrib: the unset default of the collector binary, which the hive
#   collector and swarm-otel both run (`pkgs.opentelemetry-collector-contrib`)
#   and which stamps their self-metrics.
known='bao|nix/host-modules/swarm-bao.nix|collectorServiceName = "bao"
authelia|nix/host-modules/swarm-authelia.nix|serviceName = "authelia"
forgejo|nix/host-modules/hive-forge/default.nix|serviceName = "forgejo"
swarm-controller|swarm-controller/src/vcs_metrics.rs|with_service_name("swarm-controller")
otelcol-contrib|nix/host-modules/otel.nix|package = pkgs.opentelemetry-collector-contrib'

violations=0

while IFS='|' read -r name file anchor; do
  if ! grep -qF -- "$anchor" "$file" 2>/dev/null; then
    violations=$((violations + 1))
    printf '::error file=%s::service.name "%s" is listed as emitted but %s no longer contains: %s\n' \
      "$file" "$name" "$file" "$anchor"
  fi
done <<EOF2
$known
EOF2

names="$(printf '%s\n' "$known" | cut -d'|' -f1)"
checked=0

for f in "$dashboards_dir"/*.json; do
  # The expr strings escape the quotes, so the raw file holds
  # service.name backslash-quote-equals-backslash-quote name.
  used_names="$(grep -oE '\\"service\.name\\"=\\"[^\\]+\\"' "$f" | sed -E 's/.*=\\"([^\\]+)\\"$/\1/' | sort -u || true)"
  while IFS= read -r used; do
    [ -n "$used" ] || continue
    checked=$((checked + 1))
    if ! printf '%s\n' "$names" | grep -qxF -- "$used"; then
      violations=$((violations + 1))
      printf '::error file=%s::queries service.name "%s", which nothing emits (known: %s)\n' \
        "$f" "$used" "$(printf '%s' "$names" | tr '\n' ' ')"
    fi
  done <<EOF3
$used_names
EOF3
done

if [ "$checked" -eq 0 ]; then
  echo 'check-dashboard-service-names: found zero service.name selectors — extractor or tree changed' >&2
  exit 1
fi
if [ "$violations" -gt 0 ]; then
  printf 'check-dashboard-service-names: %s violation(s)\n' "$violations" >&2
  exit 1
fi
echo "check-dashboard-service-names: $checked selector name(s) checked, clean" >&2