data "aws_availability_zones" "available" {
  state = "available"
}

locals {
  az_count = min(var.availability_zone_count, length(data.aws_availability_zones.available.names))
  azs      = slice(data.aws_availability_zones.available.names, 0, local.az_count)

  public_subnet_cidrs = [
    for index in range(local.az_count) : cidrsubnet(var.vpc_cidr, 4, index)
  ]

  private_subnet_cidrs = [
    for index in range(local.az_count) : cidrsubnet(var.vpc_cidr, 4, index + local.az_count)
  ]

  common_tags = merge(
    {
      Terraform   = "true"
      Module      = "eks-new-vpc"
      Environment = var.name
    },
    var.tags
  )

  vpc_id = var.create_vpc ? aws_vpc.this[0].id : var.existing_vpc_id

  public_subnet_ids  = var.create_vpc ? values(aws_subnet.public)[*].id : var.existing_public_subnet_ids
  private_subnet_ids = var.create_vpc ? values(aws_subnet.private)[*].id : var.existing_private_subnet_ids
}