import type { Terminal as XTerm } from "@xterm/xterm";
import type { SerializeAddon } from "@xterm/addon-serialize";

import {
  serializeTerminalForHibernate,
  type TerminalHibernateSnapshot,
} from "../terminalHibernateRuntime.ts";

export type TerminalCloseCaptureSource = "connection-log" | "hibernate-serialize" | "none";

export type TerminalCloseCapturePayload = {
  data: string;
  source: TerminalCloseCaptureSource;
};

export function scheduleTerminalCloseTeardown(teardown: () => void): void {
  if (typeof queueMicrotask === "function") {
    queueMicrotask(teardown);
    return;
  }
  setTimeout(teardown, 0);
}

export function isTerminalCloseGenerationCurrent(
  closeGeneration: number,
  currentGeneration: number,
): boolean {
  return closeGeneration === currentGeneration;
}

export function resolveConnectionLogCapturePayload(
  finalizeTerminalLogData: () => string,
): TerminalCloseCapturePayload | null {
  const data = finalizeTerminalLogData();
  if (!data) return null;
  return { data, source: "connection-log" };
}

export function resolveHibernateSnapshotCapturePayload(
  snapshot: TerminalHibernateSnapshot,
): TerminalCloseCapturePayload | null {
  const data = snapshot.snapshot
    || snapshot.contextSnapshot
    || [snapshot.scrollbackSnapshot, snapshot.viewportSnapshot].filter(Boolean).join("");
  if (!data) return null;
  return { data, source: "hibernate-serialize" };
}

export async function serializeTerminalCloseFallback(
  term: XTerm,
  serializeAddon: SerializeAddon,
  options: { preferWasm?: boolean; prepare?: () => Promise<void> } = {},
): Promise<TerminalCloseCapturePayload | null> {
  const snapshot = await serializeTerminalForHibernate(term, serializeAddon, options);
  return resolveHibernateSnapshotCapturePayload(snapshot);
}