import { constructorsForReviver, isReviverValue } from "./JSONReviver";
import { validateObject } from "./Validator";

export class JSONReviverError extends Error {
  ctor: string;
  constructor(message: string, ctor: string) {
    super(message);
    this.name = this.constructor.name;
    this.ctor = ctor;
  }
}

/**
 * A generic "smart reviver" function.
 * Looks for object values with a `ctor` property and a `data` property.
 * If it finds them, and finds a matching constructor, it hands
 * off to that `fromJSON` function, passing in the value. */
export function Reviver(_key: string, value: unknown): any {
  if (!isReviverValue(value)) {
    return value;
  }
  const ctor = constructorsForReviver[value.ctor];
  if (!ctor) {
    // Known missing constructors with special handling.
    switch (value.ctor) {
      case "AllServersMap": // Reviver removed in v0.43.1
      case "Message": // Reviver removed in v1.6.4
      case "Industry": // No longer part of save data since v2.3.0
      case "Employee": // Entire object removed from game in v2.2.0 (employees abstracted)
      case "Company": // Reviver removed in v2.6.1
      case "Faction": // Reviver removed in v2.6.1
      case "ActionIdentifier": // No longer a class as of v2.6.1
        console.warn(`Legacy load type ${value.ctor} converted to expected format while loading.`);
        return value.data;
    }
    // Missing constructor with no special handling. Throw error.
    throw new JSONReviverError(`Could not locate constructor named ${value.ctor}.`, value.ctor);
  }

  const obj = ctor.fromJSON(value);
  if (ctor.validationData !== undefined) {
    validateObject(obj, ctor.validationData);
  }
  return obj;
}