### Simplified Module
# Mandatory vpc input
variable "vpc_id" {
  type = string
}
# Optional subnet input
variable "subnets_ids" {
  type = list(string)
  default = []
}

# Get route tables from vpc
data "aws_route_tables" "vpc_rts" {
  vpc_id   = var.vpc_id
}
# If provided get route tables from subnets
data "aws_route_table" "subnet_rts" {
  count = length(var.subnets_ids)
  subnet_id = var.subnets_ids[count.index]
}

# Generate local values
locals {
  vpc_rts_ids    = data.aws_route_tables.vpc_rts.ids
  subnet_rts_ids = data.aws_route_table.subnet_rts[*].route_table_id

  rts_ids        = var.subnets_ids == [] ? local.vpc_rts_ids : local.subnet_rts_ids
}


### Outputs for troubleshooting
# inputs
output "VAR_vpc_id" {
  value = var.vpc_id
}
output "VAR_subnets_ids" {
  value = var.subnets_ids
}

# data
output "DATA_vpc_rts" {
  value = data.aws_route_tables.vpc_rts
}
output "DATA_subnet_rts" {
  value = data.aws_route_table.subnet_rts
}

# locals
output "LOCAL_vpc_rts_ids" {
  value = local.vpc_rts_ids
}
output "LOCAL_subnet_rts_ids" {
  value = local.subnet_rts_ids
}
# Written in full capital letters since it is the most interesting value
output "LOCAL_RTS_IDS" {
  value = local.rts_ids
}