# main.tf

# --------------------------------------------------------------------------------------------------
# LOCAL VARIABLES
# --------------------------------------------------------------------------------------------------

locals {
  # Create a map of zones to be created (where zone_id is not specified)
  zones_to_create = { for k, v in var.zones : k => v if try(v.zone_id, null) == null }

  # Create a map of zones to be referenced via data source (where zone_id is specified)
  zones_to_read = { for k, v in var.zones : k => v if try(v.zone_id, null) != null }

  # Merge the created resources and data sources into a single, unified map.
  # This allows record sets to reference a zone regardless of whether it was created or read.
  all_zones = merge(
    {
      for k, zone in stackit_dns_zone.this : k => zone
    },
    {
      for k, zone in data.stackit_dns_zone.this : k => zone
    }
  )

  # Flatten the nested record_sets structure into a single list, making it easy to iterate with for_each.
  # Each item in the list retains a reference to its parent zone key.
  flat_record_sets = flatten([
    for zone_key, zone_config in var.zones : [
      for record_key, record_config in try(zone_config.record_sets, {}) : {
        zone_key   = zone_key
        record_key = record_key
        name       = record_config.name
        type       = record_config.type
        records    = record_config.records
        ttl        = try(record_config.ttl, null)
        comment    = try(record_config.comment, null)
        active     = try(record_config.active, null)
      }
    ]
  ])
}

# --------------------------------------------------------------------------------------------------
# DNS ZONE RESOURCES (CREATE OR READ)
# --------------------------------------------------------------------------------------------------

# Create new DNS zones for configurations that do not have a zone_id
resource "stackit_dns_zone" "this" {
  for_each = local.zones_to_create

  project_id      = var.project_id
  name            = each.value.name
  dns_name        = each.value.dns_name
  contact_email   = try(each.value.contact_email, null)
  description     = try(each.value.description, null)
  acl             = try(each.value.acl, null)
  active          = try(each.value.active, null)
  default_ttl     = try(each.value.default_ttl, null)
  expire_time     = try(each.value.expire_time, null)
  is_reverse_zone = try(each.value.is_reverse_zone, null)
  negative_cache  = try(each.value.negative_cache, null)
  primaries       = try(each.value.primaries, null)
  refresh_time    = try(each.value.refresh_time, null)
  retry_time      = try(each.value.retry_time, null)
  type            = try(each.value.type, "primary")
}

# Read existing DNS zones for configurations that provide a zone_id
data "stackit_dns_zone" "this" {
  for_each = local.zones_to_read

  project_id = var.project_id
  zone_id    = each.value.zone_id
}

# --------------------------------------------------------------------------------------------------
# DNS RECORD SET RESOURCES
# --------------------------------------------------------------------------------------------------

resource "stackit_dns_record_set" "this" {
  # The key is a unique combination of the zone and record keys for a stable address.
  for_each = { for record in local.flat_record_sets : "${record.zone_key}.${record.record_key}" => record }

  project_id = var.project_id
  # Look up the correct zone_id from the unified 'all_zones' map
  zone_id = local.all_zones[each.value.zone_key].zone_id

  name    = each.value.name
  type    = each.value.type
  records = each.value.records
  ttl     = each.value.ttl
  comment = each.value.comment
  active  = each.value.active
}