import { Request } from 'express';
import { CustomDecorator } from '@nestjs/common';
import { PermissionsObjectPermission } from './permissions.enum';
import { RequestUser } from './user.decorator';

export const AUTH_FUNCTION_KEY = '__AUTH_FUNCTION__';

export type AuthenticationFunction = (req: Request, user: any) => boolean;

// implementation copied from SetMetadata, but tweaked to get existing values
// of the metadataKey and accumulate it with the new metadataValue
function SetMultipleMetadata(metadataKey, metadataValue): CustomDecorator {
  const decoratorFactory = (target, key, descriptor) => {
    // .start: tweak
    // descriptor?.value = function decorator; target = class decorator
    const accumulatedVal =
      Reflect.getMetadata(metadataKey, descriptor?.value ?? target) ?? [];
    accumulatedVal.push(metadataValue);
    // .end: tweak

    if (descriptor) {
      Reflect.defineMetadata(metadataKey, accumulatedVal, descriptor.value);
      return descriptor;
    }

    Reflect.defineMetadata(metadataKey, accumulatedVal, target);
    return target;
  };

  decoratorFactory.KEY = metadataKey;
  return decoratorFactory as any;
}

export function RequireAllPermissions(
  ...permissions: PermissionsObjectPermission[]
) {
  return SetMultipleMetadata(AUTH_FUNCTION_KEY, (req, user: RequestUser) =>
    permissions.every(({ seqid }) => user.permissions.includes(seqid)),
  );
}

export function RequireSomePermission(
  ...permissions: PermissionsObjectPermission[]
) {
  return SetMultipleMetadata(AUTH_FUNCTION_KEY, (req, user: RequestUser) =>
    permissions.some(({ seqid }) => user.permissions.includes(seqid)),
  );
}

export function AuthenticateCondition(func: AuthenticationFunction) {
  return SetMultipleMetadata(AUTH_FUNCTION_KEY, func);
}

export function Authenticated() {
  return SetMultipleMetadata(AUTH_FUNCTION_KEY, () => true);
}