import json
import sys
import os

def get_all_resources(planned_values):
    """Recursively collect all resources from root_module and child_modules."""
    resources = []

    root_module = planned_values.get('root_module', {})
    resources.extend(root_module.get('resources', []))

    # Recursively get resources from child modules
    def collect_from_modules(module):
        for child in module.get('child_modules', []):
            resources.extend(child.get('resources', []))
            collect_from_modules(child)

    collect_from_modules(root_module)
    return resources

def validate_plan(plan_path):
    if not os.path.exists(plan_path):
        print(f"Error: Plan file {plan_path} not found.")
        sys.exit(1)

    try:
        with open(plan_path, 'r') as f:
            plan = json.load(f)
    except json.JSONDecodeError as e:
        print(f"Error decoding JSON from {plan_path}: {e}")
        sys.exit(1)
    except Exception as e:
        print(f"Error reading file {plan_path}: {e}")
        sys.exit(1)

    # Get all resources including those in child modules
    planned_values = plan.get('planned_values', {})
    resources = get_all_resources(planned_values)

    # Check 1: Gitea Server must exist
    # Resource address: module.gitea_srv_renner_uno.proxmox_virtual_environment_container.this
    gitea_exists = False
    for res in resources:
        addr = res.get('address', '')
        if 'gitea' in addr.lower() and 'proxmox_virtual_environment_container' in addr:
            gitea_exists = True
            break

    if not gitea_exists:
        print("ERROR: Validation Failed! Gitea server is missing in the planned state (it might be deleted).")
        sys.exit(1)

    # Check 2: At least one runner must remain
    # Runner address pattern: module.runners["905"].proxmox_virtual_environment_container.this
    runner_count = 0
    for res in resources:
        addr = res.get('address', '')
        if 'runners[' in addr and 'proxmox_virtual_environment_container' in addr:
            runner_count += 1

    if runner_count < 1:
        print("ERROR: Validation Failed! No Gitea runners found in the planned state.")
        sys.exit(1)

    # Check 3: Prevent recreation of non-transient nodes
    # We fail if any node that doesnt have the transient tag would be recreated
    resource_changes = plan.get('resource_changes', [])
    for change in resource_changes:
        actions = change.get('change', {}).get('actions', [])
        # Recreation typically involves both delete and create actions for the same resource instance
        if 'delete' in actions and 'create' in actions:
            address = change.get('address', 'unknown')
            after = change.get('change', {}).get('after', {})

            # If after is None, we can't check tags, but recreation implies a new state exists.
            if after is None:
                 # This might happen if the plan is malformed or in unexpected states, but for safety:
                 print(f"WARNING: Resource {address} is being recreated but has no 'after' state to check tags.")
                 continue

            # Tags can be a list or a comma-separated string depending on provider
            tags = after.get('tags', [])
            if tags is None:
                tags = []
            elif isinstance(tags, str):
                tags = [t.strip() for t in tags.split(',')]

            if 'transient' not in tags:
                print(f"ERROR: Validation Failed! Resource {address} is being recreated but is not marked as 'transient'. Tags: {tags}")
                sys.exit(1)

    print(f"Validation Successful: Gitea server exists and {runner_count} runners will be present.")
    sys.exit(0)
if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python validate_plan.py <plan.json>")
        sys.exit(1)
    
    validate_plan(sys.argv[1])