/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.eclipse.datatools.connectivity.oda.openmrs.impl;

import java.math.BigDecimal;
import java.sql.Date;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;

import org.eclipse.datatools.connectivity.oda.IBlob;
import org.eclipse.datatools.connectivity.oda.IClob;
import org.eclipse.datatools.connectivity.oda.IResultSet;
import org.eclipse.datatools.connectivity.oda.IResultSetMetaData;
import org.eclipse.datatools.connectivity.oda.OdaException;

/**
 * Implementation class of IResultSet for an ODA runtime driver. <br>
 * For demo purpose, the auto-generated method stubs have hard-coded
 * implementation that returns a pre-defined set of meta-data and query results.
 * A custom ODA driver is expected to implement own data source specific
 * behavior in its place.
 */
public class ResultSet implements IResultSet {
    private int m_maxRows, m_currentRowId;

    private boolean wasNull = false;

    private IResultSetMetaData resultSetMetaData;

    private ListIterator<Map<String, String>> iter;

    private List<Map<String, String>> data;

    private Map<String, String> curRow;

    /**
     * Constructor that overrides the default, to accept necessary arguments.
     * 
     * @param rsmd the current result set meta data
     * @param tokens the array of Tokens to be used in this ResultSet
     * @param data the data structure holding the data from the query
     */
    public ResultSet(IResultSetMetaData rsmd, List<Map<String, String>> data) {
        this.resultSetMetaData = rsmd;
        this.data = data;
        this.iter = this.data.listIterator();
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getMetaData()
     */
    public IResultSetMetaData getMetaData() throws OdaException {
        return resultSetMetaData;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#setMaxRows(int)
     */
    public void setMaxRows(int max) throws OdaException {
        m_maxRows = max;
    }

    /**
     * Returns the maximum number of rows that can be fetched from this result
     * set.
     * 
     * @return the maximum number of rows to fetch.
     */
    protected int getMaxRows() {
        return m_maxRows;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#next()
     */
    public boolean next() throws OdaException {
        // Obey the row limit if it exists
        if (getMaxRows() > 0 && m_currentRowId > getMaxRows()) {
            return false;
        }

        // Iterate through the List elements and set the current row
        if (iter.hasNext()) {
            m_currentRowId++;
            curRow = iter.next();
            return true;
        }

        // There was no row left
        return false;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#close()
     */
    public void close() throws OdaException {
        // nullify some pointers for garbage collection
        resultSetMetaData = null;
        iter = null;
        data = null;
        curRow = null;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getRow()
     */
    public int getRow() throws OdaException {
        return m_currentRowId;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getString(int)
     */
    public String getString(int index) throws OdaException {
        return getString(resultSetMetaData.getColumnName(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getString(java.lang.String)
     */
    public String getString(String columnName) throws OdaException {
        String ret = curRow.get(columnName);
        wasNull = (ret == null);
        return ret;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getInt(int)
     */
    public int getInt(int index) throws OdaException {
        return Integer.parseInt(getString(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getInt(java.lang.String)
     */
    public int getInt(String columnName) throws OdaException {
        return Integer.parseInt(getString(columnName));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getDouble(int)
     */
    public double getDouble(int index) throws OdaException {
        String doubleRes = getString(index);
        if (doubleRes.equals("null"))
            return -1;
        else
            return Double.parseDouble(getString(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getDouble(java.lang.String)
     */
    public double getDouble(String columnName) throws OdaException {
        return Double.parseDouble(getString(columnName));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBigDecimal(int)
     */
    public BigDecimal getBigDecimal(int index) throws OdaException {
        return new BigDecimal(getString(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBigDecimal(java.lang.String)
     */
    public BigDecimal getBigDecimal(String columnName) throws OdaException {
        return new BigDecimal(getString(columnName));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getDate(int)
     */
    public Date getDate(int index) throws OdaException {
        // return Date.valueOf(getString(index));

        String date = getString(index);
        if (date.equals(""))
            return null;
        else
            return new Date(Long.parseLong(date));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getDate(java.lang.String)
     */
    public Date getDate(String columnName) throws OdaException {
        // return Date.valueOf(getString(columnName));
        return new Date(Long.parseLong(getString(columnName)));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getTime(int)
     */
    public Time getTime(int index) throws OdaException {
        // return Time.valueOf(getString(index));
        String time = getString(index);
        if (time.equals(""))
            return null;
        else
            return new Time(Long.parseLong(time));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getTime(java.lang.String)
     */
    public Time getTime(String columnName) throws OdaException {
        // return Time.valueOf(getString(columnName));
        return new Time(Long.parseLong(getString(columnName)));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getTimestamp(int)
     */
    public Timestamp getTimestamp(int index) throws OdaException {
        // return Timestamp.valueOf(getString(index));
        String timestamp = getString(index);
        if (timestamp.equals(""))
            return null;
        else
            return new Timestamp(Long.parseLong(timestamp));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getTimestamp(java.lang.String)
     */
    public Timestamp getTimestamp(String columnName) throws OdaException {
        // return Timestamp.valueOf(getString(columnName));
        return new Timestamp(Long.parseLong(getString(columnName)));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBoolean(int)
     */
    public boolean getBoolean(int index) throws OdaException {
        return Boolean.parseBoolean(getString(index));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBoolean(java.lang.String)
     */
    public boolean getBoolean(String columnName) throws OdaException {
        return Boolean.parseBoolean(getString(columnName));
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBlob(int)
     */
    public IBlob getBlob(int index) throws OdaException {
        wasNull = true;
        throw new UnsupportedOperationException();
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getBlob(java.lang.String)
     */
    public IBlob getBlob(String columnName) throws OdaException {
        wasNull = true;
        throw new UnsupportedOperationException();
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getClob(int)
     */
    public IClob getClob(int index) throws OdaException {
        wasNull = true;
        throw new UnsupportedOperationException();
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#getClob(java.lang.String)
     */
    public IClob getClob(String columnName) throws OdaException {
        wasNull = true;
        throw new UnsupportedOperationException();
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#wasNull()
     */
    public boolean wasNull() throws OdaException {
        return wasNull;
    }

    /*
     * @see org.eclipse.datatools.connectivity.oda.IResultSet#findColumn(java.lang.String)
     */
    public int findColumn(String columnName) throws OdaException {
        for (int i = 0; i < resultSetMetaData.getColumnCount(); i++) {
            if (resultSetMetaData.getColumnName(i).equals(columnName)) {
                return i;
            }
        }
        throw new OdaException("Column with name " + columnName
                + " does not exist.");
    }

}