import { Config } from "../config_builder/config";
import * as matches from "ts-matches";
import * as YAML from "yaml";
import { LegacyExpectedExports as ExpectedExports } from "../types";
import { ConfigSpec } from "../types/config-types";
import { TypeFromProps, typeFromProps } from "../utils/propertiesMatcher";

const { any, string, dictionary } = matches;

const matchConfig = dictionary([string, any]);

/**
 * Call with the configuration to get a standard getConfig for the expected exports
 * Assumption: start9/config.yaml is where the config will be stored
 * Throws: Error if there is no file
 * Throws: Error if the config.yaml isn't yaml nor config shape
 * @param spec
 * @returns
 */
export const getConfig =
  <A extends ConfigSpec>(spec: Config<A>): ExpectedExports.getConfig =>
  async (effects) => {
    const config = await effects
      .readFile({
        path: "start9/config.yaml",
        volumeId: "main",
      })
      .then((x) => YAML.parse(x))
      .then((x) => matchConfig.unsafeCast(x))
      .catch((e) => {
        effects.info(`Got error ${e} while trying to read the config`);
        return undefined;
      });

    return {
      result: {
        config,
        spec: spec.build(),
      },
    };
  };

/**
 * Call with the configuration to get a standard getConfig for the expected exports
 * Assumption: start9/config.yaml is where the config will be stored
 * Throws: Error if there is no file
 * Throws: Error if the config.yaml isn't yaml nor config shape
 * @param spec
 * @returns A funnction for getConfig and the matcher for the spec sent in
 */
export const getConfigAndMatcher = <Spec extends ConfigSpec>(
  spec: Config<Spec>
): [
  ExpectedExports.getConfig,
  matches.Parser<unknown, TypeFromProps<Spec>>
] => {
  const specBuilt: Spec = spec.build();

  return [
    async (effects) => {
      const config = await effects
        .readFile({
          path: "start9/config.yaml",
          volumeId: "main",
        })
        .then((x) => YAML.parse(x))
        .then((x) => matchConfig.unsafeCast(x))
        .catch((e) => {
          effects.info(`Got error ${e} while trying to read the config`);
          return undefined;
        });

      return {
        result: {
          config,
          spec: specBuilt,
        },
      };
    },
    typeFromProps(specBuilt),
  ];
};