terraform {
  required_version = "~> 0.12.21"
  required_providers {
    azurerm = "~> 1.44"
  }
}

locals {
  linkrtbs = distinct(flatten([
    for link in var.sub_links : [
      for rtb in try(link.subnet.rtb, []) : {
        subnet               = link.subnet.name
        route_table_name     = link.subnet.rtb.name
      }
    ]
  ]))
}

resource "azurerm_subnet_route_table_association" "azsub_rtb_link" {
  depends_on = [var.azsub_link_depends_on]
  for_each = {for link in try(local.linkrtbs, []): link.subnet => link}

  subnet_id      = data.azurerm_subnet.sub[each.value.subnet].id
  route_table_id = data.azurerm_route_table.rtb[each.value.route_table_name].id
}

locals {
  linknatgws = distinct(flatten([
    for link in var.sub_links : [
      for rtb in try(link.subnet.natgw, []) : {
        subnet               = link.subnet.name
        nat_gateway_name     = link.subnet.natgw.name
      }
    ]
  ]))
}

resource "azurerm_subnet_nat_gateway_association" "azsub_natgw_link" {
  depends_on = [var.azsub_link_depends_on]
  for_each = {for link in try(local.linknatgws, []): link.subnet => link}

  subnet_id      = data.azurerm_subnet.sub[each.value.subnet].id
  nat_gateway_id = data.azurerm_nat_gateway.natgw[each.value.nat_gateway_name].id
}

locals {
  subnets = distinct(flatten([
    for link in var.sub_links : {
        name                 = link.subnet.name
        virtual_network_name = link.subnet.virtual_network_name
        resource_group_name  = link.subnet.resource_group_name
    }
  ]))
}

data "azurerm_subnet" "sub" {
  depends_on = [var.azsub_link_depends_on]
  for_each = {for subnet in local.subnets: subnet.name => subnet}

  name                 = each.value.name
  virtual_network_name = each.value.virtual_network_name
  resource_group_name  = each.value.resource_group_name
}

locals {
  rtbs = distinct(flatten([
    for link in var.sub_links : [
      for rtb in try(link.subnet.rtb, []) : {
        name                = link.subnet.rtb.name
        resource_group_name = link.subnet.rtb.resource_group_name
      }
    ]
  ]))
}

data "azurerm_route_table" "rtb" {
  depends_on = [var.azsub_link_depends_on]
  for_each = {for rtb in local.rtbs: rtb.name => rtb}

  name                = each.value.name
  resource_group_name = each.value.resource_group_name
}

locals {
  natgws = distinct(flatten([
    for link in var.sub_links : [
      for rtb in try(link.subnet.natgw, []) : {
        name                = link.natgw.name
        resource_group_name = link.natgw.resource_group_name
      }
    ]
  ]))
}

data "azurerm_nat_gateway" "natgw" {
  depends_on = [var.azsub_link_depends_on]
  for_each = {for natgw in local.natgws: natgw.name => natgw}

  name                = each.value.name
  resource_group_name = each.value.resource_group_name
}