import type { RecordingDeviceSlot } from "@/lib/db/schema";
import type { ConnectedDeviceInfo } from "./types";

export interface DeviceRemapEntry {
  slotLabel: string;
  recordedBleName: string;
  matchedDeviceIndex: number | null;
}

/**
 * Best-effort name match from a recording's saved device slots to the
 * currently-connected devices. Web Bluetooth exposes no stable hardware id
 * across sessions, so this is inherently approximate: two devices sharing an
 * identical advertised name are indistinguishable and must be disambiguated
 * manually in the remap UI - this isn't a bug, it's a hard BLE limitation.
 */
export function autoMapDeviceSlots(
  slots: RecordingDeviceSlot[],
  connectedDevices: ConnectedDeviceInfo[],
): DeviceRemapEntry[] {
  const usedIndexes = new Set<number>();

  return slots.map((slot) => {
    const normalizedSlotName = slot.recordedBleName.trim().toLowerCase();

    const exact = connectedDevices.find(
      (d) => !usedIndexes.has(d.index) && d.name.trim().toLowerCase() === normalizedSlotName,
    );
    const partial =
      exact ??
      connectedDevices.find(
        (d) =>
          !usedIndexes.has(d.index) &&
          (d.name.toLowerCase().includes(normalizedSlotName) ||
            normalizedSlotName.includes(d.name.toLowerCase())),
      );

    if (partial) usedIndexes.add(partial.index);

    return {
      slotLabel: slot.slotLabel,
      recordedBleName: slot.recordedBleName,
      matchedDeviceIndex: partial?.index ?? null,
    };
  });
}