locals {
  # 1. Find and decode YAML files
  alert_files = fileset(
    "${path.root}/${var.alerts_dir}",
    "**/*.yaml"
  )

  decoded_files = [
    for f in local.alert_files :
    yamldecode(file("${path.root}/${var.alerts_dir}/${f}"))
  ]

  # 2. Flatten: each YAML may define multiple groups
  groups_raw = flatten([
    for doc in local.decoded_files : try(doc.groups, [])
  ])

  # 3. Inject defaults (datasource, folder, interval) and sanitize models
  groups = [
    for g in local.groups_raw : merge(g, {
      uid        = try(g.uid, lower(replace(g.name, " ", "-")))
      folder_uid = var.folder_uid
      interval   = try(g.interval, "${var.default_interval_seconds}s")

      rules = [
        for r in g.rules : merge(r, {
          data = [
            for d in r.data : merge(d, {
              # Preserve __expr__ for expressions, otherwise inject default UID
              datasource_uid = (
                try(d.datasourceUid, "") == "__expr__"
                ? "__expr__"
                : var.datasource_uid
              )

              relative_time_range = try(d.relativeTimeRange, { from = 600, to = 0 })

              # Sanitize model: remove keys Grafana ignores to prevent plan drift
              model = {
                for k, v in d.model : k => v
                if !(k == "queryType" || k == "query_type")
              }
            })
          ]
        })
      ]
    })
  ]
}