package de.intevation.gnv.geobackend.base;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * This Class is the DefaultImplementation of the
 * Interface ResultDescriptor
 * @author Tim Englich <tim.englich@intevation.de>
 *
 */
public class DefaultResultDescriptor implements ResultDescriptor {

    /**
     *The Uid of this Class
     */
    private static final long serialVersionUID = 7016889733270716130L;
    /**
     * The Names of the Columns of one Result
     */
    private List<String> columnNames = new ArrayList<String>();
    /**
     * The Name of the Classes of the Values of one Result.
     */
    private List<String> columnClassNames = new ArrayList<String>();
    /**
     * The Lookup for the Columnindex of the Columnnames
     */
    private Map<String, Integer> columnIndexLookup = new HashMap<String, Integer>();

    /**
     * Constructor
     */
    public DefaultResultDescriptor() {
        super();
    }

    /**
     * @see de.intevation.gnv.geobackend.base.ResultDescriptor#getColumnClassName(int)
     */
    public String getColumnClassName(int column) {
        return this.columnClassNames.get(column);
    }

    /**
     * @see de.intevation.gnv.geobackend.base.ResultDescriptor#getColumnCount()
     */
    public int getColumnCount() {
        return this.columnClassNames.size();
    }

    /**
     * @see de.intevation.gnv.geobackend.base.ResultDescriptor#getColumnName(int)
     */
    public String getColumnName(int column) {
        return this.columnNames.get(column);
    }

    /**
     * @see de.intevation.gnv.geobackend.base.ResultDescriptor#addColumn(java.lang.String, java.lang.String)
     */
    public void addColumn(String name, String className) {
        this.columnClassNames.add(className);
        this.columnNames.add(name);
        this.columnIndexLookup.put(name,this.columnNames.size()-1);
    }

    /**
     * @see de.intevation.gnv.geobackend.base.ResultDescriptor#getColumnIndices(java.lang.String[])
     */
    public int [] getColumnIndices(String [] columnNames) {
        if (columnNames == null) {
            return null;
        }
        int [] indices = new int[columnNames.length];
        for (int i = 0; i < indices.length; ++i) {
            indices[i] = this.getColumnIndex(columnNames[i]);
        }
        return indices;
    }

    /**
     * @see de.intevation.gnv.geobackend.base.ResultDescriptor#getColumnIndex(java.lang.String)
     */
    public int getColumnIndex(String columnName) {

        Integer value = this.columnIndexLookup.get(columnName);
        return value != null ? value.intValue() : -1;
    }

    /**
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder("[");
        int N = Math.min(columnNames.size(), columnClassNames.size());
        for (int i = 0; i < N; ++i) {
            if (i > 0) {
                sb.append(", ");
            }
            sb.append(columnNames.get(i))
              .append(": ")
              .append(columnClassNames.get(i));
        }
        sb.append(']');
        return sb.toString();
    }
}