/**
 * =============================================================================
 *
 * ORCID (R) Open Source
 * http://orcid.org
 *
 * Copyright (c) 2012-2014 ORCID, Inc.
 * Licensed under an MIT-Style License (MIT)
 * http://orcid.org/open-source-license
 *
 * This copyright and license information (including a link to the full license)
 * shall be included in its entirety in all copies or substantial portion of
 * the software.
 *
 * =============================================================================
 */
package org.orcid.core.version.impl;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.orcid.core.version.V2Convertible;
import org.orcid.core.version.V2VersionConverter;
import org.orcid.core.version.V2VersionConverterChain;

/**
 * 
 * @author Will Simpson
 *
 */
public class V2VersionConverterChainImpl implements V2VersionConverterChain {

    private List<V2VersionConverter> converters;
    private List<V2VersionConverter> descendingConverters;
    private ArrayList<String> versionIndex;

    public void setConverters(List<V2VersionConverter> converters) {
        this.converters = converters;
        this.descendingConverters = new ArrayList<>(converters);
        Collections.reverse(this.descendingConverters);
        versionIndex = new ArrayList<String>();
        for (int i = 0; i < converters.size(); i++) {
            if (i == 0) {
                versionIndex.add(converters.get(i).getLowerVersion());
            }
            versionIndex.add(converters.get(i).getUpperVersion());
        }
    }

    @Override
    public V2Convertible downgrade(V2Convertible objectToDowngrade, String requiredVersion) {
        for (V2VersionConverter converter : descendingConverters) {
            if (compareVersion(converter.getLowerVersion(), requiredVersion) > -1) {
                objectToDowngrade = converter.downgrade(objectToDowngrade);
            } else {
                return objectToDowngrade;
            }
        }
        return objectToDowngrade;
    }

    @Override
    public V2Convertible upgrade(V2Convertible objectToUpgrade, String requiredVersion) {
        String objectVersion = objectToUpgrade.getCurrentVersion();
        
        if(compareVersion(objectVersion, requiredVersion) < 0) {
            for (V2VersionConverter converter : converters) {  
                if(compareVersion(objectVersion, converter.getUpperVersion()) < 0) {
                    if (compareVersion(converter.getUpperVersion(), requiredVersion) < 1) {
                        objectToUpgrade = converter.upgrade(objectToUpgrade);
                    } else {
                        return objectToUpgrade;
                    }
                }
            }
        }        
                
        return objectToUpgrade;
    }

    private int compareVersion(String v1, String v2) {
        if (versionIndex.indexOf(v1) < versionIndex.indexOf(v2)) {
            return -1;
        } else if (versionIndex.indexOf(v1) > versionIndex.indexOf(v2)) {
            return 1;
        }
        return 0;
    }

}