/*-
 * ============LICENSE_START=======================================================
 * ONAP : APPC
 * ================================================================================
 * Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * Copyright (C) 2017 Amdocs
 * =============================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * ============LICENSE_END=========================================================
 */
package org.onap.appc.ccadaptor;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class XmlUtil {

    private static final Logger log = LoggerFactory.getLogger(XmlUtil.class);

    public static String getXml(Map<String, String> varmap, String var) {
        Object o = createStructure(varmap, var);
        return generateXml(o, 0);
    }

    private static Object createStructure(Map<String, String> flatmap, String var) {
        if (flatmap.containsKey(var)) {
            return flatmap.get(var);
        }

        Map<String, Object> mm = new HashMap<>();
        for (String k : flatmap.keySet()) {
            if (k.startsWith(var + ".")) {
                int i1 = k.indexOf('.', var.length() + 1);
                int i2 = k.indexOf('[', var.length() + 1);
                int i3 = k.length();
                if (i1 > 0 && i1 < i3) {
                    i3 = i1;
                }
                if (i2 > 0 && i2 < i3) {
                    i3 = i2;
                }
                String k1 = k.substring(var.length() + 1, i3);
                String var1 = k.substring(0, i3);
                if (!mm.containsKey(k1)) {
                    Object str = createStructure(flatmap, var1);
                    if (str != null && (!(str instanceof String) || ((String) str).trim().length() > 0)) {
                        mm.put(k1, str);
                    }
                }
            }
        }
        if (!mm.isEmpty()) {
            return mm;
        }

        boolean arrayFound = false;
        for (String k : flatmap.keySet()) {
            if (k.startsWith(var + "[")) {
                arrayFound = true;
                break;
            }
        }

        if (arrayFound) {
            List<Object> ll = new ArrayList<>();

            int length = Integer.MAX_VALUE;
            String lengthStr = flatmap.get(var + "_length");
            if (lengthStr != null) {
                try {
                    length = Integer.parseInt(lengthStr);
                } catch (Exception e) {
                    log.warn("Invalid number for " + var + "_length:" + lengthStr);
                }
            }

            for (int i = 0; i < length; i++) {
                Object v = createStructure(flatmap, var + '[' + i + ']');
                if (v == null) {
                    break;
                }
                ll.add(v);
            }

            if (!ll.isEmpty()) {
                return ll;
            }
        }

        return null;
    }

    @SuppressWarnings("unchecked")
    private static String generateXml(Object o, int indent) {
        if (o == null) {
            return null;
        }

        if (o instanceof String) {
            return (String) o;
        }

        if (o instanceof Map) {
            StringBuilder ss = new StringBuilder();
            Map<String, Object> mm = (Map<String, Object>) o;
            for (String k : mm.keySet()) {
                Object v = mm.get(k);
                if (v instanceof String) {
                    ss.append(pad(indent)).append('<').append(k).append('>');
                    ss.append(v);
                    ss.append("</").append(k).append('>').append('\n');
                } else if (v instanceof Map) {
                    ss.append(pad(indent)).append('<').append(k).append('>').append('\n');
                    ss.append(generateXml(v, indent + 1));
                    ss.append(pad(indent)).append("</").append(k).append('>').append('\n');
                } else if (v instanceof List) {
                    List<Object> ll = (List<Object>) v;
                    for (Object o1 : ll) {
                        ss.append(pad(indent)).append('<').append(k).append('>').append('\n');
                        ss.append(generateXml(o1, indent + 1));
                        ss.append(pad(indent)).append("</").append(k).append('>').append('\n');
                    }
                }
            }
            return ss.toString();
        }

        return null;
    }

    private static String pad(int n) {
        String s = "";
        for (int i = 0; i < n; i++) {
            s += '\t';
        }
        return s;
    }
}