import { Capacitor, registerPlugin, type PluginListenerHandle } from "@capacitor/core";

export type FoldPosture = "flat" | "tabletop" | "book" | "unknown";

export interface PostureChangedEvent {
  posture: FoldPosture;
  hingeTop: number;
  hingeBottom: number;
  hingeLeft: number;
  hingeRight: number;
  hingeHeight: number;
}

interface FoldPlugin {
  startMonitoring(): Promise<{ posture: FoldPosture }>;
  stopMonitoring(): Promise<void>;
  addListener(
    event: "postureChanged",
    fn: (e: PostureChangedEvent) => void,
  ): Promise<PluginListenerHandle> | PluginListenerHandle;
}

const Fold = registerPlugin<FoldPlugin>("Fold");

export async function startFoldMonitoring(
  onChange: (e: PostureChangedEvent) => void,
): Promise<() => void> {
  if (!Capacitor.isNativePlatform() || Capacitor.getPlatform() !== "android") {
    return () => {};
  }
  let initial: FoldPosture = "flat";
  try {
    const r = await Fold.startMonitoring();
    initial = r.posture;
  } catch {
    return () => {};
  }
  onChange({
    posture: initial,
    hingeTop: 0,
    hingeBottom: 0,
    hingeLeft: 0,
    hingeRight: 0,
    hingeHeight: 0,
  });
  const handle = await Fold.addListener("postureChanged", onChange);
  return () => {
    void handle.remove();
    void Fold.stopMonitoring().catch(() => {});
  };
}