"""CAU service: Cluster-Aware Updating via PowerShell remoting (WinRM)."""

from collections.abc import AsyncIterator

from app.core.exceptions import CAUError
from app.core.logging import get_logger
from app.services.winrm import WinRMCredentials, WinRMService

logger = get_logger(__name__)


class CAUService:
    """Orchestrates Invoke-CauRun against a Windows failover cluster."""

    def __init__(
        self,
        cluster_name: str,
        access_node: str,
        port: int = 5985,
        credentials: WinRMCredentials | None = None,
    ) -> None:
        self.cluster_name = cluster_name
        self.winrm = WinRMService(access_node, port=port, credentials=credentials)

    async def get_cluster_nodes(self) -> list[dict[str, str]]:
        """List cluster nodes and their state."""
        script = f"""
        Import-Module FailoverClusters
        Get-ClusterNode -Cluster {self.cluster_name} |
            Select-Object Name, State |
            ForEach-Object {{ "$($_.Name)|$($_.State)" }}
        """
        output = await self.winrm.run_powershell(script)
        nodes = []
        for line in output.splitlines():
            if "|" in line:
                name, state = line.split("|", 1)
                nodes.append({"name": name.strip(), "state": state.strip()})
        return nodes

    async def get_cau_status(self) -> str:
        """Return the last CAU run summary."""
        script = f"""
        Import-Module ClusterAwareUpdating
        Get-CauRun -ClusterName {self.cluster_name} |
            Select-Object -First 1 |
            Format-List | Out-String
        """
        return await self.winrm.run_powershell(script)

    async def test_cluster(self) -> tuple[bool, str]:
        """Verify the cluster is reachable and CAU module present."""
        try:
            nodes = await self.get_cluster_nodes()
            if not nodes:
                return False, "Keine Cluster-Knoten gefunden"
            return True, f"Cluster OK — {len(nodes)} Knoten"
        except Exception as exc:  # noqa: BLE001
            return False, str(exc)

    async def invoke_cau_run(self) -> AsyncIterator[str]:
        """Start a CAU run and stream per-node progress lines.

        Scaffold implementation: starts Invoke-CauRun and polls Get-CauReport.
        TODO: true live streaming of per-node phases via event log polling.
        """
        script = f"""
        Import-Module ClusterAwareUpdating
        Invoke-CauRun -ClusterName {self.cluster_name} `
            -Force -Confirm:$false -WaitForCompletion |
            Out-String
        """
        try:
            async for line in self.winrm.stream_powershell(script):
                yield line
        except Exception as exc:  # noqa: BLE001
            raise CAUError(f"CAU-Lauf fehlgeschlagen: {exc}") from exc