"""Stack discovery for the CloudFormation Stack Updater."""

from __future__ import annotations

from cfn_updater.config import NON_UPDATABLE_STATUSES
from cfn_updater.models import DiscoveredStack


# Statuses to exclude from list_stacks (DELETE_COMPLETE stacks are hidden by default
# but we explicitly exclude them to be safe).
_ACTIVE_STACK_STATUSES = [
    "CREATE_IN_PROGRESS",
    "CREATE_FAILED",
    "CREATE_COMPLETE",
    "ROLLBACK_IN_PROGRESS",
    "ROLLBACK_FAILED",
    "ROLLBACK_COMPLETE",
    "DELETE_IN_PROGRESS",
    "DELETE_FAILED",
    "UPDATE_IN_PROGRESS",
    "UPDATE_COMPLETE_CLEANUP_IN_PROGRESS",
    "UPDATE_COMPLETE",
    "UPDATE_FAILED",
    "UPDATE_ROLLBACK_IN_PROGRESS",
    "UPDATE_ROLLBACK_FAILED",
    "UPDATE_ROLLBACK_COMPLETE_CLEANUP_IN_PROGRESS",
    "UPDATE_ROLLBACK_COMPLETE",
    "REVIEW_IN_PROGRESS",
    "IMPORT_IN_PROGRESS",
    "IMPORT_COMPLETE",
    "IMPORT_ROLLBACK_IN_PROGRESS",
    "IMPORT_ROLLBACK_FAILED",
    "IMPORT_ROLLBACK_COMPLETE",
]


def discover_stacks(cfn_client, prefix: str) -> list[DiscoveredStack]:
    """List all stacks matching *prefix*. Paginates through all results.

    Marks each stack as updatable or not based on its status against
    ``NON_UPDATABLE_STATUSES``.
    """
    stacks: list[DiscoveredStack] = []
    next_token: str | None = None

    while True:
        kwargs: dict = {"StackStatusFilter": _ACTIVE_STACK_STATUSES}
        if next_token is not None:
            kwargs["NextToken"] = next_token

        response = cfn_client.list_stacks(**kwargs)

        for summary in response.get("StackSummaries", []):
            name = summary["StackName"]
            if not name.startswith(prefix):
                continue
            status = summary["StackStatus"]
            updatable = status not in NON_UPDATABLE_STATUSES
            stacks.append(DiscoveredStack(name=name, status=status, updatable=updatable))

        next_token = response.get("NextToken")
        if not next_token:
            break

    return stacks