import gp from "@sagold/json-pointer";
import { get } from "@sagold/json-query";
import getTypeId from "./getTypeId";
import types from "./types";
import { JSONSchema, JSONPointer } from "../types";

const isObject = (value: unknown) => Object.prototype.toString.call(value) === "[object Object]";

type TypeDef = { pointer: JSONPointer; def: unknown };

/**
 * Returns a list of all (direct) type definitions from the given schema
 * @param schema
 * @return list of type definition, given as { pointer, def }
 */
export default function getTypeDefs(schema: JSONSchema): TypeDef[] {
    const defs: TypeDef[] = [];
    const id = getTypeId(schema);
    if (id == null) {
        return defs;
    }

    let type;
    if (Array.isArray(id)) {
        // since types can also be declared as a set of types, merge the definitions
        // maybe this will require a more sophisticated approach
        type = {};
        for (let i = 0, l = id.length; i < l; i += 1) {
            Object.assign(type, types[id[i]]);
        }
    } else {
        type = types[id];
    }

    if (type.definitions == null) {
        return defs;
    }

    type.definitions.forEach((query: string) => {
        get(schema, query, (value: unknown, key, parent, pointer) => {
            if (isObject(value) && getTypeId(value)) {
                defs.push({ pointer: gp.join(gp.split(pointer), false), def: value });
            }
        });
    });

    return defs;
}