package org.maltparser.parser.algorithm.planar;

import java.util.Stack;

import org.maltparser.core.exception.MaltChainedException;
import org.maltparser.core.syntaxgraph.DependencyStructure;
import org.maltparser.core.syntaxgraph.node.DependencyNode;
import org.maltparser.parser.ParserConfiguration;
import org.maltparser.parser.ParsingException;
/**
 * @author Carlos Gomez Rodriguez
 *
 */
public class PlanarConfig extends ParserConfiguration {
        // Root Handling
        /*
        public static final int STRICT = 1; //root tokens unattached, Reduce not permissible
        public static final int RELAXED = 2; //root tokens unattached, Reduce permissible
        public static final int NORMAL = 3; //root tokens attached to Root with RightArc
        */
        
        //Connectedness enforcing
        public static final int NO_CONNECTEDNESS = 1;
        public static final int REDUCE_ONLY = 2; //connectedness enforced on reduce only
        public static final int FULL_CONNECTEDNESS = 3; //connectedness enforced on shift and reduce
        
        // Root Handling
        public static final int NORMAL = 1; //root tokens attached to Root with RightArc
        public static final int RELAXED = 2; //root tokens unattached
        
        //Constraints
        public final boolean SINGLE_HEAD = true; //single-head constraint
        public boolean noCoveredRoots = false; //no-covered-roots constraint
        public boolean acyclicity = true; //acyclicity constraint
        public int connectedness = NO_CONNECTEDNESS; //connectedness constraint
        
        
        private final Stack<DependencyNode> stack;
        private final Stack<DependencyNode> input;
        private DependencyStructure dependencyGraph;
        
        
        //root handling: explicitly create links to dummy root or not?
        private int rootHandling;

        
        public PlanarConfig(String noCoveredRoots , String acyclicity , String connectedness , String rootHandling ) throws MaltChainedException {
                super();
                stack = new Stack<DependencyNode>();
                input = new Stack<DependencyNode>();
                setRootHandling(rootHandling);
                setNoCoveredRoots(Boolean.valueOf(noCoveredRoots));
                setAcyclicity(Boolean.valueOf(acyclicity));
                setConnectedness(connectedness);
        }
        
        public Stack<DependencyNode> getStack() {
                return stack;
        }
        
        public Stack<DependencyNode> getInput() {
                return input;
        }
        
        public DependencyStructure getDependencyStructure() {
                return dependencyGraph;
        }
        
        public boolean isTerminalState() {
                return input.isEmpty();
        }
        
        public DependencyNode getStackNode(int index) throws MaltChainedException {
                if (index < 0) {
                        throw new ParsingException("Stack index must be non-negative in feature specification. ");
                }
                if (stack.size()-index > 0) {
                        return stack.get(stack.size()-1-index);
                }
                return null;
        }
        
        public DependencyNode getInputNode(int index) throws MaltChainedException {
                if (index < 0) {
                        throw new ParsingException("Input index must be non-negative in feature specification. ");
                }
                if (input.size()-index > 0) {
                        return input.get(input.size()-1-index);
                }       
                return null;
        }
        
        public void setDependencyGraph(DependencyStructure source) throws MaltChainedException {
                this.dependencyGraph = source;
//              dependencyGraph.clear();
//              for (int index : source.getTokenIndices()) {
//                      DependencyNode gnode = source.getDependencyNode(index);
//                      DependencyNode pnode = dependencyGraph.addDependencyNode(gnode.getIndex());
//                      for (SymbolTable table : gnode.getLabelTypes()) {
//                              pnode.addLabel(table, gnode.getLabelSymbol(table));
//                      }
//                      
//                      if (gnode.hasHead()) {
//                              Edge s = gnode.getHeadEdge();
//                              Edge t = dependencyGraph.addDependencyEdge(s.getSource().getIndex(), s.getTarget().getIndex());
//                              
//                              for (SymbolTable table : s.getLabelTypes()) {
//                                      t.addLabel(table, s.getLabelSymbol(table));
//                              }
//                      }
//              }
//              for (SymbolTable table : source.getDefaultRootEdgeLabels().keySet()) {
//                      dependencyGraph.setDefaultRootEdgeLabel(table, source.getDefaultRootEdgeLabelSymbol(table));
//              }
        }
        
        public DependencyStructure getDependencyGraph() {
                return dependencyGraph;
        }
        
        public void initialize(ParserConfiguration parserConfiguration) throws MaltChainedException {
                if (parserConfiguration != null) {
                        PlanarConfig planarConfig = (PlanarConfig)parserConfiguration;
                        Stack<DependencyNode> sourceStack = planarConfig.getStack();
                        Stack<DependencyNode> sourceInput = planarConfig.getInput();
                        setDependencyGraph(planarConfig.getDependencyGraph());
                        for (int i = 0, n = sourceStack.size(); i < n; i++) {
                                stack.add(dependencyGraph.getDependencyNode(sourceStack.get(i).getIndex()));
                        }
                        for (int i = 0, n = sourceInput.size(); i < n; i++) {
                                input.add(dependencyGraph.getDependencyNode(sourceInput.get(i).getIndex()));
                        }
                } else {
                        stack.push(dependencyGraph.getDependencyRoot());
                        for (int i = dependencyGraph.getHighestTokenIndex(); i > 0; i--) {
                                final DependencyNode node = dependencyGraph.getDependencyNode(i);
                                if (node != null && !node.hasHead()) { 
                                        input.push(node);
                                }
                        }
                }
        }
        
        public void initialize() throws MaltChainedException {
                stack.push(dependencyGraph.getDependencyRoot());
                for (int i = dependencyGraph.getHighestTokenIndex(); i > 0; i--) {
                        final DependencyNode node = dependencyGraph.getDependencyNode(i);
                        if (node != null && !node.hasHead()) { 
                                input.push(node);
                        }
                }
        }
        /*
        public int getRootHandling() {
                return rootHandling;
        }
        */
        
        public boolean requiresSingleHead()
        {
                return SINGLE_HEAD;
        }
        
        public boolean requiresNoCoveredRoots()
        {
                return noCoveredRoots;
        }
        
        public boolean requiresAcyclicity()
        {
                return acyclicity;
        }
        
        public boolean requiresConnectednessCheckOnReduce()
        {
                return connectedness != NO_CONNECTEDNESS;
        }
        
        public boolean requiresConnectednessCheckOnShift()
        {
                return connectedness == FULL_CONNECTEDNESS;
        }
        
        public void setNoCoveredRoots ( boolean value ) {noCoveredRoots = value;}
        
        public void setAcyclicity ( boolean value ) {acyclicity = value;}

        protected void setConnectedness(String conn) throws MaltChainedException {
                if (conn.equalsIgnoreCase("none")) {
                        connectedness = NO_CONNECTEDNESS;
                } else if (conn.equalsIgnoreCase("reduceonly")) {
                        connectedness = REDUCE_ONLY;
                } else if (conn.equalsIgnoreCase("full")) {
                        connectedness = FULL_CONNECTEDNESS;
                } else {
                        throw new ParsingException("The connectedness constraint option '"+conn+"' is unknown");
                }
        }
        
        /*
        public void setRootHandling(int rootHandling) {
                this.rootHandling = rootHandling;
        }
        
        protected void setRootHandling(String rh) throws MaltChainedException {
                if (rh.equalsIgnoreCase("strict")) {
                        rootHandling = STRICT;
                } else if (rh.equalsIgnoreCase("relaxed")) {
                        rootHandling = RELAXED;
                } else if (rh.equalsIgnoreCase("normal")) {
                        rootHandling = NORMAL;
                } else {
                        throw new ParsingException("The root handling '"+rh+"' is unknown");
                }
        }
        */
        
        public int getRootHandling() {
                return rootHandling;
        }
        
        protected void setRootHandling(String rh) throws MaltChainedException {
                if (rh.equalsIgnoreCase("relaxed")) {
                        rootHandling = RELAXED;
                } else if (rh.equalsIgnoreCase("normal")) {
                        rootHandling = NORMAL;
                } else {
                        throw new ParsingException("The root handling '"+rh+"' is unknown");
                }
        }
        
        public void clear() throws MaltChainedException {
//              dependencyGraph.clear();
                stack.clear();
                input.clear();
                historyNode = null;
        }
        
        public boolean equals(Object obj) {
                if (this == obj)
                        return true;
                if (obj == null)
                        return false;
                if (getClass() != obj.getClass())
                        return false;
                PlanarConfig that = (PlanarConfig)obj;
                
                if (stack.size() != that.getStack().size()) 
                        return false;
                if (input.size() != that.getInput().size())
                        return false;
                if (dependencyGraph.nEdges() != that.getDependencyGraph().nEdges())
                        return false;
                for (int i = 0; i < stack.size(); i++) {
                        if (stack.get(i).getIndex() != that.getStack().get(i).getIndex()) {
                                return false;
                        }
                }
                for (int i = 0; i < input.size(); i++) {
                        if (input.get(i).getIndex() != that.getInput().get(i).getIndex()) {
                                return false;
                        }
                }               
                return dependencyGraph.getEdges().equals(that.getDependencyGraph().getEdges());
        }
        
        public String toString() {
                final StringBuilder sb = new StringBuilder();
                sb.append(stack.size());
                sb.append(", ");
                sb.append(input.size());
                sb.append(", ");
                sb.append(dependencyGraph.nEdges());
                return sb.toString();
        }
}