package org.maltparser.core.feature.map;

import org.maltparser.core.exception.MaltChainedException;
import org.maltparser.core.feature.FeatureException;
import org.maltparser.core.feature.function.FeatureFunction;
import org.maltparser.core.feature.function.FeatureMapFunction;
import org.maltparser.core.feature.value.FeatureValue;
import org.maltparser.core.feature.value.MultipleFeatureValue;
import org.maltparser.core.feature.value.SingleFeatureValue;
import org.maltparser.core.io.dataformat.ColumnDescription;
import org.maltparser.core.io.dataformat.DataFormatInstance;
import org.maltparser.core.symbol.SymbolTable;
import org.maltparser.core.symbol.SymbolTableHandler;
/**
*
*
* @author Johan Hall
*/
public final class PrefixFeature implements FeatureMapFunction {
        public final static Class<?>[] paramTypes = { org.maltparser.core.syntaxgraph.feature.InputColumnFeature.class, java.lang.Integer.class };
        private FeatureFunction parentFeature;
        private MultipleFeatureValue multipleFeatureValue;
        private final SymbolTableHandler tableHandler;
        private SymbolTable table;
        private final DataFormatInstance dataFormatInstance;
        private ColumnDescription column;
        private int prefixLength;

        public PrefixFeature(DataFormatInstance dataFormatInstance, SymbolTableHandler tableHandler) throws MaltChainedException {
                this.dataFormatInstance = dataFormatInstance;
                this.tableHandler = tableHandler;
                this.multipleFeatureValue = new MultipleFeatureValue(this);
        }
        
        public void initialize(Object[] arguments) throws MaltChainedException {
                if (arguments.length != 2) {
                        throw new FeatureException("Could not initialize PrefixFeature: number of arguments are not correct. ");
                }
                if (!(arguments[0] instanceof FeatureFunction)) {
                        throw new FeatureException("Could not initialize PrefixFeature: the first argument is not a feature. ");
                }
                if (!(arguments[1] instanceof Integer)) {
                        throw new FeatureException("Could not initialize PrefixFeature: the second argument is not a string. ");
                }
                setParentFeature((FeatureFunction)arguments[0]);
                setPrefixLength(((Integer)arguments[1]).intValue());
                ColumnDescription parentColumn = dataFormatInstance.getColumnDescriptionByName(parentFeature.getSymbolTable().getName());
                if (parentColumn.getType() != ColumnDescription.STRING) {
                        throw new FeatureException("Could not initialize PrefixFeature: the first argument must be a string. ");
                }
                setColumn(dataFormatInstance.addInternalColumnDescription(tableHandler, "PREFIX_"+prefixLength+"_"+parentFeature.getSymbolTable().getName(), parentColumn));
                setSymbolTable(tableHandler.getSymbolTable(column.getName()));
//              setSymbolTable(tableHandler.addSymbolTable("PREFIX_"+prefixLength+"_"+parentFeature.getSymbolTable().getName(), parentFeature.getSymbolTable()));
        }
        
        public Class<?>[] getParameterTypes() {
                return paramTypes; 
        }
        
        public FeatureValue getFeatureValue() {
                return multipleFeatureValue;
        }
        
        public int getCode(String symbol) throws MaltChainedException {
                return table.getSymbolStringToCode(symbol);
        }

        public String getSymbol(int code) throws MaltChainedException {
                return table.getSymbolCodeToString(code);
        }
        
        public void update() throws MaltChainedException {
                parentFeature.update();
                FeatureValue value = parentFeature.getFeatureValue();
                if (value instanceof SingleFeatureValue) {
                        String symbol = ((SingleFeatureValue)value).getSymbol();
                        if (((FeatureValue)value).isNullValue()) {
                                multipleFeatureValue.addFeatureValue(parentFeature.getSymbolTable().getSymbolStringToCode(symbol), symbol);
                                multipleFeatureValue.setNullValue(true);
                        } else {
                                String prefixStr;
                                if (symbol.length()-prefixLength > 0) {
                                        prefixStr = symbol.substring(0, prefixLength);
                                } else {
                                        prefixStr = symbol;
                                }
                                int code = table.addSymbol(prefixStr);
                                multipleFeatureValue.addFeatureValue(code, prefixStr);
                                multipleFeatureValue.setNullValue(false);
                        }
                } else if (value instanceof MultipleFeatureValue) {
                        multipleFeatureValue.reset();
                        if (((MultipleFeatureValue)value).isNullValue()) {
                                multipleFeatureValue.addFeatureValue(parentFeature.getSymbolTable().getSymbolStringToCode(((MultipleFeatureValue)value).getFirstSymbol()), ((MultipleFeatureValue)value).getFirstSymbol());
                                multipleFeatureValue.setNullValue(true);
                        } else {
                                for (String symbol : ((MultipleFeatureValue)value).getSymbols()) {
                                        String prefixStr;
                                        if (symbol.length()-prefixLength > 0) {
                                                prefixStr = symbol.substring(0, prefixLength);
                                        } else {
                                                prefixStr = symbol;
                                        }
                                        int code = table.addSymbol(prefixStr);
                                        multipleFeatureValue.addFeatureValue(code, prefixStr);
                                        multipleFeatureValue.setNullValue(true);
                                }
                        }
                }
        }
        
        public FeatureFunction getParentFeature() {
                return parentFeature;
        } 
        
        public void setParentFeature(FeatureFunction feature) {
                this.parentFeature = feature;
        }
        
        public int getPrefixLength() {
                return prefixLength;
        }

        public void setPrefixLength(int prefixLength) {
                this.prefixLength = prefixLength;
        }

        public SymbolTableHandler getTableHandler() {
                return tableHandler;
        }

        public SymbolTable getSymbolTable() {
                return table;
        }

        public void setSymbolTable(SymbolTable table) {
                this.table = table;
        }
        
        public DataFormatInstance getDataFormatInstance() {
                return dataFormatInstance;
        }
        
        public ColumnDescription getColumn() {
                return column;
        }
        
        protected void setColumn(ColumnDescription column) {
                this.column = column;
        }
        
        public  int getType() {
                return column.getType();
        }
        
        public String getMapIdentifier() {
                return getSymbolTable().getName();
        }
        
        public boolean equals(Object obj) {
                if (this == obj)
                        return true;
                if (obj == null)
                        return false;
                if (getClass() != obj.getClass())
                        return false;
                return obj.toString().equals(this.toString());
        }
        
        public String toString() {
                final StringBuilder sb = new StringBuilder();
                sb.append("Prefix(");
                sb.append(parentFeature.toString());
                sb.append(", ");
                sb.append(prefixLength);
                sb.append(')');
                return sb.toString();
        }
}