import { getRamCost } from "./RamCostGenerator";
import type { WorkerScript } from "./WorkerScript";
import { helpers } from "./NetscriptHelpers";
import { ScriptArg } from "./ScriptArg";
import { NSEnums } from "src/ScriptEditor/NetscriptDefinitions";
import { NSFull } from "src/NetscriptFunctions";

type ExternalFunction = (...args: any[]) => void;

export type ExternalAPILayer = {
  [key: string]: ExternalAPILayer | ExternalFunction | ScriptArg[];
};

type InternalFunction<F extends ExternalFunction> = (
  ctx: NetscriptContext,
) => ((...args: unknown[]) => ReturnType<F>) & F;

export type InternalAPI<API> = {
  [Property in keyof API]: API[Property] extends ExternalFunction
    ? InternalFunction<API[Property]>
    : API[Property] extends NSEnums
    ? NSEnums
    : API[Property] extends ScriptArg[]
    ? ScriptArg[]
    : API[Property] extends object
    ? InternalAPI<API[Property]>
    : never;
};

export type NetscriptContext = {
  workerScript: WorkerScript;
  function: string;
  functionPath: string;
};

function wrapFunction(
  wrappedAPI: ExternalAPILayer,
  workerScript: WorkerScript,
  func: (_ctx: NetscriptContext) => (...args: unknown[]) => unknown,
  ...tree: string[]
): void {
  const functionPath = tree.join(".");
  const functionName = tree.pop();
  if (typeof functionName !== "string") {
    throw helpers.makeBasicErrorMsg(workerScript, "Failure occurred while wrapping netscript api", "INITIALIZATION");
  }
  const ctx = {
    workerScript,
    function: functionName,
    functionPath,
  };
  function wrappedFunction(...args: unknown[]): unknown {
    helpers.checkEnvFlags(ctx);
    helpers.updateDynamicRam(ctx, getRamCost(...tree, ctx.function));
    return func(ctx)(...args);
  }
  const parent = getNestedProperty(wrappedAPI, tree);
  Object.defineProperty(parent, functionName, {
    value: wrappedFunction,
    writable: true,
    enumerable: true,
  });
}

export function wrapAPI(workerScript: WorkerScript, namespace: object, args: ScriptArg[]): NSFull {
  const wrappedAPI = wrapAPILayer({}, workerScript, namespace);
  wrappedAPI.args = args;
  return wrappedAPI as unknown as NSFull;
}

export function wrapAPILayer(
  wrappedAPI: ExternalAPILayer,
  workerScript: WorkerScript,
  namespace: object,
  ...tree: string[]
) {
  for (const [key, value] of Object.entries(namespace)) {
    if (typeof value === "function") {
      wrapFunction(wrappedAPI, workerScript, value, ...tree, key);
    } else if (Array.isArray(value)) {
      setNestedProperty(wrappedAPI, value.slice(), key);
    } else if (typeof value === "object") {
      wrapAPILayer(wrappedAPI, workerScript, value, ...tree, key);
    } else {
      setNestedProperty(wrappedAPI, value, ...tree, key);
    }
  }
  return wrappedAPI;
}

function setNestedProperty(root: any, value: unknown, ...tree: string[]): void {
  let target = root;
  const key = tree.pop();
  if (!key) throw new Error("Failure occurred while wrapping netscript api (setNestedProperty)");
  for (const branch of tree) {
    target[branch] ??= {};
    target = target[branch];
  }
  target[key] = value;
}

function getNestedProperty(root: any, tree: string[]): unknown {
  let target = root;
  for (const branch of tree) {
    target[branch] ??= {};
    target = target[branch];
  }
  return target;
}