from __future__ import annotations

from datetime import datetime, timezone

from app.core.command_runner import CommandError
from app.core.command_runner import CommandRunner


class ServiceManager:
    def __init__(self, command_runner: CommandRunner) -> None:
        self.command_runner = command_runner

    def enable_service(self, service_name: str) -> None:
        self.command_runner.run(["systemctl", "enable", service_name])

    def disable_service(self, service_name: str) -> None:
        self.command_runner.run(["systemctl", "disable", service_name])

    def start_service(self, service_name: str) -> None:
        self.command_runner.run(["systemctl", "start", service_name])

    def stop_service(self, service_name: str) -> None:
        self.command_runner.run(["systemctl", "stop", service_name])

    def restart_service(self, service_name: str) -> None:
        self.command_runner.run(["systemctl", "restart", service_name])

    def reset_failed(self, service_name: str) -> None:
        self.command_runner.run(["systemctl", "reset-failed", service_name])

    def assert_service_active(self, service_name: str) -> None:
        result = self.command_runner.run(["systemctl", "is-active", service_name])
        if result.stdout.strip() != "active":
            raise RuntimeError(f"Service is not active: {service_name}")

    def get_service_status(self, service_name: str) -> dict[str, object]:
        command = [
            "systemctl",
            "show",
            service_name,
            "--no-pager",
            "--property=LoadState",
            "--property=ActiveState",
            "--property=SubState",
            "--property=UnitFileState",
        ]
        error_message: str | None = None
        try:
            output = self.command_runner.run(command, timeout=5).stdout
        except CommandError as error:
            output = error.stdout
            error_message = str(error)
        except Exception as error:
            output = ""
            error_message = str(error)

        properties = self._parse_properties(output)
        load_state = properties.get("LoadState", "unknown") or "unknown"
        active_state = properties.get("ActiveState", "unknown") or "unknown"
        sub_state = properties.get("SubState", "unknown") or "unknown"
        unit_file_state = properties.get("UnitFileState", "unknown") or "unknown"
        active = load_state == "loaded" and active_state == "active"
        enabled = unit_file_state in {"enabled", "enabled-runtime"}

        if load_state == "not-found":
            status = "not-found"
        elif active_state != "unknown":
            status = active_state
        else:
            status = "unknown"

        return {
            "serviceName": service_name,
            "loadState": load_state,
            "activeState": active_state,
            "subState": sub_state,
            "unitFileState": unit_file_state,
            "active": active,
            "enabled": enabled,
            "healthy": active,
            "status": status,
            "checkedAt": datetime.now(timezone.utc).isoformat(timespec="seconds").replace("+00:00", "Z"),
            "errorMessage": error_message,
        }

    @staticmethod
    def _parse_properties(output: str) -> dict[str, str]:
        properties: dict[str, str] = {}
        for line in output.splitlines():
            key, separator, value = line.partition("=")
            if separator and key:
                properties[key.strip()] = value.strip()
        return properties