"""Scenario manager — loads and switches between operational scenarios."""

from importlib import import_module
from typing import Any

SCENARIO_MODULES = {
    "normal_ops": "mcp_servers.data.scenarios.normal_ops",
    "weather_disruption_ord": "mcp_servers.data.scenarios.weather_disruption_ord",
    "maintenance_delay_sfo": "mcp_servers.data.scenarios.maintenance_delay_sfo",
    "crew_swap_ewr": "mcp_servers.data.scenarios.crew_swap_ewr",
}


class ScenarioManager:
    """Manages the active scenario. Singleton — all MCP servers share one instance."""

    def __init__(self) -> None:
        self._active_id: str = "weather_disruption_ord"
        self._cache: dict[str, Any] = {}

    @property
    def active_id(self) -> str:
        return self._active_id

    def set_active(self, scenario_id: str) -> dict:
        if scenario_id not in SCENARIO_MODULES:
            raise ValueError(
                f"Unknown scenario: {scenario_id}. "
                f"Available: {', '.join(SCENARIO_MODULES.keys())}"
            )
        self._active_id = scenario_id
        return self.get_metadata()

    def get_metadata(self, scenario_id: str | None = None) -> dict:
        mod = self._load(scenario_id or self._active_id)
        return {
            "scenario_id": mod.SCENARIO_ID,
            "name": mod.SCENARIO_NAME,
            "description": mod.SCENARIO_DESCRIPTION,
            "hubs": mod.SCENARIO_HUBS,
            "flight_count": len(mod.FLIGHTS),
            "disrupted_flights": sum(
                1 for f in mod.FLIGHTS if f.status != "ON_TIME"
            ),
        }

    def list_scenarios(self) -> list[dict]:
        return [self.get_metadata(sid) for sid in SCENARIO_MODULES]

    def _load(self, scenario_id: str) -> Any:
        if scenario_id not in self._cache:
            self._cache[scenario_id] = import_module(SCENARIO_MODULES[scenario_id])
        return self._cache[scenario_id]

    @property
    def _module(self) -> Any:
        return self._load(self._active_id)

    @property
    def flights(self):
        return self._module.FLIGHTS

    @property
    def crew(self):
        return self._module.CREW

    @property
    def crew_notes(self) -> dict[str, list[str]]:
        return self._module.CREW_NOTES

    @property
    def maintenance(self):
        return self._module.MAINTENANCE

    @property
    def rebookings(self):
        return self._module.REBOOKINGS

    @property
    def passengers(self):
        return self._module.PASSENGERS


# Singleton
scenario_manager = ScenarioManager()