package com.metaweb.gridworks.operations;

 import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import org.apache.commons.lang.StringUtils;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONWriter;

import com.metaweb.gridworks.history.HistoryEntry;
import com.metaweb.gridworks.model.AbstractOperation;
import com.metaweb.gridworks.model.Cell;
import com.metaweb.gridworks.model.Column;
import com.metaweb.gridworks.model.Project;
import com.metaweb.gridworks.model.Row;
import com.metaweb.gridworks.model.changes.MassRowChange;

public class MultiValuedCellSplitOperation extends AbstractOperation {
    final protected String  _columnName;
    final protected String  _keyColumnName;
    final protected String  _separator;
    final protected String  _mode;

    static public AbstractOperation reconstruct(Project project, JSONObject obj) throws Exception {
        return new MultiValuedCellSplitOperation(
            obj.getString("columnName"),
            obj.getString("keyColumnName"),
            obj.getString("separator"),
            obj.getString("mode")
        );
    }
    
    public MultiValuedCellSplitOperation(
        String      columnName,
        String      keyColumnName,
        String    separator,
        String    mode
    ) {
        _columnName = columnName;
        _keyColumnName = keyColumnName;
        _separator = separator;
        _mode = mode;
    }

   public void write(JSONWriter writer, Properties options)
           throws JSONException {
       
       writer.object();
       writer.key("op"); writer.value(OperationRegistry.s_opClassToName.get(this.getClass()));
       writer.key("description"); writer.value("Split multi-valued cells in column " + _columnName);
       writer.key("columnName"); writer.value(_columnName);
       writer.key("keyColumnName"); writer.value(_keyColumnName);
       writer.key("separator"); writer.value(_separator);
       writer.key("mode"); writer.value(_mode);
       writer.endObject();
    }

    protected String getBriefDescription(Project project) {
        return "Split multi-valued cells in column " + _columnName;
    }

    @Override
    protected HistoryEntry createHistoryEntry(Project project) throws Exception {
        Column column = project.columnModel.getColumnByName(_columnName);
        if (column == null) {
            throw new Exception("No column named " + _columnName);
        }
        int cellIndex = column.getCellIndex();
        
        Column keyColumn = project.columnModel.getColumnByName(_keyColumnName);
        if (keyColumn == null) {
            throw new Exception("No key column named " + _keyColumnName);
        }
        int keyCellIndex = keyColumn.getCellIndex();
        
        List<Row> newRows = new ArrayList<Row>();
        
        int oldRowCount = project.rows.size();
        for (int r = 0; r < oldRowCount; r++) {
            Row oldRow = project.rows.get(r);
            if (oldRow.isCellBlank(cellIndex)) {
                newRows.add(oldRow.dup());
                continue;
            }
            
            Object value = oldRow.getCellValue(cellIndex);
            String s = value instanceof String ? ((String) value) : value.toString();
            String[] values = null;
            if (_mode.equals("regex")) {
                values = s.split(_separator);
            } else {
                values = StringUtils.splitByWholeSeparator(s, _separator);
            }
            
            if (values.length < 2) {
                newRows.add(oldRow.dup());
                continue;
            }
            
            // First value goes into the same row
            {
                Row firstNewRow = oldRow.dup();
                firstNewRow.setCell(cellIndex, new Cell(values[0].trim(), null));
                
                newRows.add(firstNewRow);
            }
            
            int r2 = r + 1;
            for (int v = 1; v < values.length; v++) {
                Cell newCell = new Cell(values[v].trim(), null);
                
                if (r2 < project.rows.size()) {
                    Row oldRow2 = project.rows.get(r2);
                    if (oldRow2.isCellBlank(cellIndex) && 
                        oldRow2.isCellBlank(keyCellIndex)) {
                        
                        Row newRow = oldRow2.dup();
                        newRow.setCell(cellIndex, newCell);
                        
                        newRows.add(newRow);
                        r2++;
                        
                        continue;
                    }
                }
                
                Row newRow = new Row(cellIndex + 1);
                newRow.setCell(cellIndex, newCell);
                
                newRows.add(newRow);
            }
            
            r = r2 - 1; // r will be incremented by the for loop anyway
        }
        
        return new HistoryEntry(
            project, 
            getBriefDescription(null), 
            this, 
            new MassRowChange(newRows)
        );
    }
}