/**
 * Serialize arbitrary AAF `globalEvent` payloads for display. Plain
 * `JSON.stringify` throws on BigInt and circular graphs; `String(obj)` becomes
 * `[object Object]`, which is what users saw for events like
 * `customerStateChange`, `callEnded`, etc.
 */

function isTypedArray(v: unknown): v is ArrayBufferView {
  return (
    typeof ArrayBuffer !== "undefined" &&
    ArrayBuffer.isView(v) &&
    !(v instanceof DataView)
  );
}

/** Deep-clone into JSON-safe values (Lossy by design — for debugging only.) */
export function toPrintableJson(value: unknown, seen: WeakSet<object> = new WeakSet()): unknown {
  if (value === undefined) return undefined;
  if (value === null) return null;

  const t = typeof value;
  if (t === "string" || t === "number" || t === "boolean") return value;
  if (t === "bigint") return value.toString();
  if (t === "symbol") return String(value);
  if (t === "function") return `[Function ${(value as Function).name || "anonymous"}]`;

  if (value instanceof Date) return value.toISOString();

  if (t === "object") {
    if (seen.has(value as object)) return "[Circular]";
    seen.add(value as object);
    try {
      if (Array.isArray(value)) {
        return value.map((item) => toPrintableJson(item, seen));
      }
      if (isTypedArray(value)) {
        return Array.from(value as unknown as ArrayLike<number>);
      }
      if (value instanceof Map) {
        const o: Record<string, unknown> = {};
        value.forEach((v, k) => {
          o[String(k)] = toPrintableJson(v, seen);
        });
        return o;
      }
      if (value instanceof Set) {
        return Array.from(value, (item) => toPrintableJson(item, seen));
      }

      const out: Record<string, unknown> = {};
      for (const key of Reflect.ownKeys(value as object)) {
        if (typeof key === "symbol") {
          out[`[${String(key)}]`] = toPrintableJson((value as Record<PropertyKey, unknown>)[key], seen);
          continue;
        }
        try {
          const v = (value as Record<string, unknown>)[key as string];
          out[String(key)] = toPrintableJson(v, seen);
        } catch {
          out[String(key)] = "[Unserializable]";
        }
      }
      return out;
    } finally {
      seen.delete(value as object);
    }
  }

  return String(value);
}

/** Pretty-print any value for UI / clipboard (never returns `[object Object]` for plain objects). */
export function safeJson(value: unknown): string {
  if (value === undefined) return "undefined";
  try {
    const printable = toPrintableJson(value);
    return JSON.stringify(printable, null, 2);
  } catch {
    try {
      return JSON.stringify(value, (_k, v) => {
        if (typeof v === "bigint") return v.toString();
        return v;
      }, 2);
    } catch {
      return String(value);
    }
  }
}