package com.hubilon.json;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.ToNumberPolicy;

import java.util.Map;

/**
 * JSON reader, backed by Gson. Kept as a single call site so the rest of the
 * app depends on this API rather than on Gson directly.
 *
 * ToNumberPolicy.LONG_OR_DOUBLE keeps whole numbers as Long (so re-serializing
 * a pass-through field like expected.status doesn't turn "200" into "200.0").
 */
public final class Json {

    private static final Gson GSON = new GsonBuilder()
            .setObjectToNumberStrategy(ToNumberPolicy.LONG_OR_DOUBLE)
            .create();

    private Json() {
    }

    @SuppressWarnings("unchecked")
    public static Map<String, Object> parseObject(String text) {
        try {
            Map<String, Object> result = GSON.fromJson(text, Map.class);
            if (result == null) {
                throw new JsonException("JSON document is empty or 'null'");
            }
            return result;
        } catch (RuntimeException e) {
            throw new JsonException(e.getMessage());
        }
    }

    public static final class JsonException extends RuntimeException {
        public JsonException(String message) {
            super(message);
        }
    }
}