/**
 * Copyright 2023 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

# tfdoc:file:description Route resources.

locals {
  _googleapis_ranges = {
    private      = "199.36.153.8/30"
    private-6    = "2600:2d00:2:2000::/64"
    restricted   = "199.36.153.4/30"
    restricted-6 = "2600:2d00:2:1000::/64"
  }
  _googleapis_routes = {
    for k, v in local._googleapis_ranges : "${k}-googleapis" => {
      description   = "Terraform-managed."
      dest_range    = v
      next_hop      = "default-internet-gateway"
      next_hop_type = "gateway"
      priority      = 1000
      tags          = null
    }
    if(
      var.vpc_create &&
      lookup(coalesce(var.create_googleapis_routes, {}), k, false)
    )
  }
  _routes = merge(local._googleapis_routes, coalesce(var.routes, {}))
  routes = {
    gateway    = { for k, v in local._routes : k => v if v.next_hop_type == "gateway" }
    ilb        = { for k, v in local._routes : k => v if v.next_hop_type == "ilb" }
    instance   = { for k, v in local._routes : k => v if v.next_hop_type == "instance" }
    ip         = { for k, v in local._routes : k => v if v.next_hop_type == "ip" }
    vpn_tunnel = { for k, v in local._routes : k => v if v.next_hop_type == "vpn_tunnel" }
  }
}

resource "google_compute_route" "gateway" {
  for_each         = local.routes.gateway
  project          = var.project_id
  network          = local.network.name
  name             = "${var.name}-${each.key}"
  description      = each.value.description
  dest_range       = each.value.dest_range
  priority         = each.value.priority
  tags             = each.value.tags
  next_hop_gateway = each.value.next_hop
}

resource "google_compute_route" "ilb" {
  for_each     = local.routes.ilb
  project      = var.project_id
  network      = local.network.name
  name         = "${var.name}-${each.key}"
  description  = each.value.description
  dest_range   = each.value.dest_range
  priority     = each.value.priority
  tags         = each.value.tags
  next_hop_ilb = each.value.next_hop
}

resource "google_compute_route" "instance" {
  for_each          = local.routes.instance
  project           = var.project_id
  network           = local.network.name
  name              = "${var.name}-${each.key}"
  description       = each.value.description
  dest_range        = each.value.dest_range
  priority          = each.value.priority
  tags              = each.value.tags
  next_hop_instance = each.value.next_hop
  # not setting the instance zone will trigger a refresh
  next_hop_instance_zone = regex("zones/([^/]+)/", each.value.next_hop)[0]
}

resource "google_compute_route" "ip" {
  for_each    = local.routes.ip
  project     = var.project_id
  network     = local.network.name
  name        = "${var.name}-${each.key}"
  description = each.value.description
  dest_range  = each.value.dest_range
  priority    = each.value.priority
  tags        = each.value.tags
  next_hop_ip = each.value.next_hop
}

resource "google_compute_route" "vpn_tunnel" {
  for_each            = local.routes.vpn_tunnel
  project             = var.project_id
  network             = local.network.name
  name                = "${var.name}-${each.key}"
  description         = each.value.description
  dest_range          = each.value.dest_range
  priority            = each.value.priority
  tags                = each.value.tags
  next_hop_vpn_tunnel = each.value.next_hop
}

resource "google_network_connectivity_policy_based_route" "default" {
  for_each              = var.policy_based_routes
  project               = var.project_id
  network               = local.network.id
  name                  = "${var.name}-${each.key}"
  description           = each.value.description
  priority              = each.value.priority
  next_hop_other_routes = each.value.use_default_routing ? "DEFAULT_ROUTING" : null
  next_hop_ilb_ip       = each.value.use_default_routing ? null : each.value.next_hop_ilb_ip
  filter {
    protocol_version = "IPV4"
    ip_protocol      = each.value.filter.ip_protocol
    dest_range       = each.value.filter.dest_range
    src_range        = each.value.filter.src_range
  }
  dynamic "virtual_machine" {
    for_each = each.value.target.tags != null ? [""] : []
    content {
      tags = each.value.target.tags
    }
  }
  dynamic "interconnect_attachment" {
    for_each = each.value.target.interconnect_attachment != null ? [""] : []
    content {
      region = each.value.target.interconnect_attachment
    }
  }
}