main.py

import json
import sys

if len(sys.argv) < 3:
    print(f"usage: {sys.argv[0]} resources.tfstate resources12.tfstate")
    exit(1)

source = sys.argv[1]
dest = sys.argv[2]

# lookup table of resources to convert
conversions = {
    "azurerm_logic_app_action_custom": "aws_instance",
    "azurerm_logic_app_trigger_custom": "aws_instance",
    "azurerm_logic_app_workflow": "aws_instance",
    "azurerm_virtual_desktop_application_group": "aws_instance",
    "azurerm_virtual_desktop_host_pool": "aws_instance",
    "azurerm_virtual_desktop_workspace": "aws_instance",
    "azurerm_virtual_desktop_workspace_application_group_association": "aws_instance"
}

with open(source, "rb") as _fh:
    resources = json.loads(_fh.read())

# replace the TF version from 13 to 12
resources['terraform_version'] =  "0.12.28"

# in TF13, all dependencies modules starts with "module.<module-name>
module = "module.vdi."

for resource in resources.get("resources"):
    # remove the keyword "module", it does not exist in TF12
    del(resource['module'])
    provider = resource.get("provider")
    # remove "unknown provider" which makes fail the BE
    if "random" in resource.get("provider", ""):
        resources.get("resources").remove(resource)
        continue

    rt = resource.get("type")
    if rt and conversions.get(rt):
        resource["type"] = conversions.get(rt)

    # TODO: use regex to extract only the "provider.<provider>"
    resource["provider"] = "provider.azurerm"
    instances = resource.get("instances", [])
    for instance in instances:
        dependencies = instance.get("dependencies", [])

        for i in range(0, len(dependencies)):
            dep = dependencies[i]
            # in TF13, all dependencies modules starts with
            # "module.<module-name>"
            if dep.startswith(module):
                dep = dep[len(module):]
                rt = dep.split(".")[0]
                if conversions.get(rt):
                    dep = f"{conversions.get(rt)}.{dep.split('.')[1]}"
            elif dep.startswith("module.network."):
                dep = dep[len("module.network."):]
            # remove "random" dependencies
            elif "random" in dep:
                dependencies.remove(i)
                continue
            dependencies[i] = dep

with open(dest, "w") as _fh:
    _fh.write(json.dumps(resources))