import { makeWrapResolversPlugin } from "postgraphile";
import { Validator } from "./Validator";

/**
 * Options
 *
 * @export
 * @interface Options
 */
export interface Options {
  inputFieldName: string;
}

export type MutationsMap = { [key: string]: Validator<any, any, any, any> };

/**
 *
 *
 * @export
 * @param {{ [key: string]: Validator<any, any, any, any> }} mutations
 * @param {Options} [options={
 *     inputFieldName: "input",
 *   }]
 */
export function ValidationPlugin(
  mutations: MutationsMap,
  options: Options = {
    inputFieldName: "input",
  }
) {
  makeWrapResolversPlugin(
    (context) => {
      if (context.scope.isRootMutation) {
        return { scope: context.scope };
      }
      return null;
    },
    ({ scope }) =>
      async (resolver, source, args, context, resolveInfo) => {
        // check if validator is registered for mutation
        const mutationName = scope.fieldName;
        if (!mutations[mutationName]) {
          console.log("no validation for mutation", mutationName);
          return resolver(source, args, context, resolveInfo);
        }
        // get validator
        const validator = mutations[mutationName];
        // get input
        const input = args[options.inputFieldName];
        // call validator
        const validationResult = await validator(input, {
          resolver,
          source,
          args,
          context,
          resolveInfo,
        } as any);
        // resolve or throw
        if (!validationResult || Object.keys(validationResult).length != 0) {
          throw new Error(
            `ValidationError(${JSON.stringify(validationResult)})`
          );
        }
        return resolver(source, args, context, resolveInfo);
      }
  );
}