import java.util.function.Function;

import org.apache.commons.lang3.StringUtils;

import com.google.common.base.CaseFormat;

public class ParamMap<K, V> implements Map<K, V> {

    private final Map<K, V> parent;

    public ParamMap(final Map<K, V> parent) {
        this.parent = parent;
    }

    public Map<K, V> getParent() {
        return parent;
    }

    }

    public Map<String, Object> asMap() {
        return new ParamMap<>(new HashMap<>(getDataMap(params)));
    }

    protected static Map<String, Object> getDataMap(final Map<String, Object> params) {
        if (params instanceof final ParamMap<String, Object> paramMap) {
            return paramMap.getParent();
        }
        return params;
    }

        Map<String, String[]> paramMap;

        paramMap = filter.parseQueryString("a=1", "UTF-8");
        assertEquals(1, paramMap.size());
        assertEquals("1", paramMap.get("a")[0]);

        paramMap = filter.parseQueryString("a=1&b=2", "UTF-8");
        assertEquals(2, paramMap.size());
        assertEquals("1", paramMap.get("a")[0]);
        assertEquals("2", paramMap.get("b")[0]);

        paramMap = ParameterUtil.parse(value);
        assertEquals(1, paramMap.size());
        assertEquals("", paramMap.get("a"));

        value = "a";
        paramMap = ParameterUtil.parse(value);
        assertEquals(1, paramMap.size());
        assertEquals("", paramMap.get("a"));

        value = "a=b=c";
        paramMap = ParameterUtil.parse(value);
        assertEquals(1, paramMap.size());

        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String proxyHost = fessConfig.getHttpProxyHost();
        final String proxyPort = fessConfig.getHttpProxyPort();
        if (StringUtil.isNotBlank(proxyHost) && StringUtil.isNotBlank(proxyPort)) {
            paramMap.put(Param.Client.PROXY_HOST, proxyHost);
            paramMap.put(Param.Client.PROXY_PORT, proxyPort);

        assertNull(paramMap.get("xxx"));
        assertEquals("111", paramMap.get("aaa"));
        assertEquals("222", paramMap.get("aaa_bbb"));
        assertEquals("222", paramMap.get("aaaBbb"));
        assertEquals("222", paramMap.get("AaaBbb"));
        assertNull(paramMap.get("aaabbb"));
        assertEquals("333", paramMap.get("aaa_bbb_ccc"));
        assertEquals("333", paramMap.get("aaaBbbCcc"));

        String value;
        final Map<String, Object> paramMap = new HashMap<>();
        paramMap.put("param1", "PARAM1");
        paramMap.put("param2", "PARAM2+");
        paramMap.put("param3", "PARAM3*");

        value = "\"abc\"";
        assertEquals("abc", dataStore.convertValue(Constants.DEFAULT_SCRIPT, value, paramMap));

        value = "param1";

        return (u, m) -> {
            final Map<String, Object> paramMap = new HashMap<>();
            paramMap.put("url", u);
            paramMap.put("matcher", m);
            final Object value =
                    ComponentUtil.getScriptEngineFactory().getScriptEngine(Constants.DEFAULT_SCRIPT).evaluate(template, paramMap);
            if (value == null) {
                return u;
            }

                final String scheme = paramMap.get(CRAWLER_WEB_AUTH + "." + webAuthName + ".scheme");

                final AuthScheme authScheme = getAuthScheme(paramMap, webAuthName, scheme);
                final AuthScope authScope = getAuthScope(webAuthName, scheme, paramMap);
                final Credentials credentials = getCredentials(webAuthName, scheme, paramMap);

                }
            }
        });
    }

    protected String getParamValue(final DataStoreParams paramMap, final String key, final String defaultValue) {
        return paramMap.getAsString(key, defaultValue);
    }

    protected void addDocument(final DataStoreParams paramMap, final Map<String, Object> dataMap) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();