Terraform convert list from csv to map

Question

I have a csv file with thoses values to create azure vm.

"os_type","vm_hostname","vm_os_simple","vm_size","data_sa1_type","data_disk1_size_gb","data_sa2_type","data_disk2_size_gb","enable_accelerated_networking"

I would like to have an idea how to create a map of data disk informations to create multiple data disks by vm's with datadisk names based on machine name and data disk index.

for exemple if I created a var.data_disks map object like below

data_disks = [
{
    name                 = "disk1"
    disk_size_gb         = 100
    storage_account_type = "StandardSSD_LRS"
},
{
    name                 = "disk2"
    disk_size_gb         = 200
    storage_account_type = "Standard_LRS"
}
]

I can get my information like this

  vm_data_disks = { for idx, data_disk in var.data_disks : data_disk.name => { idx : idx, data_disk : data_disk,}}

which produced

Changes to Outputs:
  + nulresource = {
      + disk1 = {
          + data_disk = {
              + disk_size_gb         = 100
              + name                 = "disk1"
              + storage_account_type = "StandardSSD_LRS"
            }
          + idx       = 0
        }
      + disk2 = {
          + data_disk = {
              + disk_size_gb         = 200
              + name                 = "disk2"
              + storage_account_type = "Standard_LRS"
            }
          + idx       = 1
        }

but in my case I used csvdecode to get my information

 locals {
   vmparameters = csvdecode(file("input.csv"))
}

and I would like from the csv input create the same résult like the output above my goals is to loop throught this map my to create my datadisk. below is what I tried by it's it not good

# dynamic storage_data_disk {
  #     for_each = [for k,v in {for val in local.vmparameters : val.nb_data_disk  => index(local.vmparameters, val) if val.os_type == "windows"} : k ]
  #     content {
  #       name              = format("${upper(each.key)}-datadisk%02", storage_data_disk.key + 1)
  #       create_option     = "Empty"
  #       lun               = 0
  #       disk_size_gb      = each.value.data_disk_size_gb
  #       managed_disk_type = each.value.data_sa_type
  #     }
  #   }

Some ideas ?