package org.simantics.graph.representation;

import java.io.BufferedInputStream;
import java.io.DataInput;
import java.io.DataInputStream;
import java.io.InputStream;
import java.math.BigInteger;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.simantics.databoard.Bindings;
import org.simantics.databoard.Datatypes;
import org.simantics.databoard.binding.Binding;
import org.simantics.databoard.binding.mutable.Variant;
import org.simantics.databoard.container.DataContainers;
import org.simantics.databoard.type.Datatype;

import gnu.trove.list.array.TIntArrayList;
import gnu.trove.map.hash.TIntObjectHashMap;
import gnu.trove.set.hash.TLongHashSet;

/**
 * @author Antti Villberg
 * @since 1.24.0
 */
public class PrettyPrintTG extends TransferableGraphUtils {

	int blankCounter = 0;
	MessageDigest m;

	private final Pattern versionExtractPattern = Pattern.compile("^.*-(\\d+\\.\\d+)");

	final StringBuilder output;
	final Map<String,String> ontologies = new HashMap<>(knownOntologies);
	final Set<String> referencedOntologies = new TreeSet<>();

	static class ResourceInfo {
		final boolean hasURI;
		final String name;
		final int resource;
		boolean newResource = false;
		
		// -1 = no owner, -2 = multiple owners
		int owner = -1;
		int ownerPredicate = 0;
		String aliasURI = null;
		TIntArrayList owned = new TIntArrayList();
		//TIntObjectHashMap<TIntHashSet> statements = new TIntObjectHashMap<TIntHashSet>();
		public ResourceInfo(boolean hasURI, String name, int resource) {
			this.hasURI = hasURI;
			this.name = name;
			this.resource = resource;
		}
	}

	public PrettyPrintTG(StringBuilder b) throws NoSuchAlgorithmException {
		output = b;
		m = MessageDigest.getInstance("SHA-256");
	}

	public PrettyPrintTG() throws NoSuchAlgorithmException {
		this(new StringBuilder());
	}

	TIntObjectHashMap<ResourceInfo> infos = new TIntObjectHashMap<>();

	String tgNodeName(String name) {
		if(name.contains(" ")) return "\"" + name + "\"";
		else return name;
	}

	ResourceInfo recurseURI(TransferableGraph1 graph, Identity parent, String parentName) {
		String name = parentName + "." + tgNodeName(getName(parent));
		ResourceInfo info = new ResourceInfo(true, name, parent.resource); 
		infos.put(parent.resource, info);
		for(Identity child : getChildren(graph, parent)) {
			recurseURI(graph, child, name);
		}
		return info;
	}

	void discoverBlank(TransferableGraph1 graph, int resource, TIntArrayList todo) throws Exception {
		TIntArrayList statements = getStatements(graph, resource);
		for(int i=0;i<statements.size();i+=2) {
			int object = statements.get(i+1);
			Identity objectId = getIdentity(graph, object);
			if(objectId != null) {
				if(objectId.definition instanceof External) continue;
			}
			Value value = TransferableGraphUtils.findValue(graph, object);
			if(value != null) {
				infos.put(object, new ResourceInfo(false, printValue(value), object));
				continue;
			}
			ResourceInfo existing = infos.get(object);
			if(existing == null) {
				existing = new ResourceInfo(false, "blank" + blankCounter++, object);
				infos.put(object, existing);
				todo.add(object);
			}
		}
	}

	void discoverOwners(TransferableGraph1 graph, ResourceInfo info) {
		int resource = info.resource;
		TIntArrayList statements = getStatements(graph, resource);
		for(int i=0;i<statements.size();i+=2) {
			int predicate = statements.get(i);
			int object = statements.get(i+1);
			ResourceInfo existing = infos.get(object);
			if(existing == null) continue;
			if(existing.owner == -1) {
				existing.owner = resource;
				existing.ownerPredicate = predicate;
				//System.err.println("First owner " + info.name + " => " + predicateURI + " " + existing.name);
			} else {
				existing.owner = -2;
				//System.err.println("Multiple owners " + info.name + " => " + predicateURI + " " + existing.name);
			}
		}
		
	}

	String printValue(Value value) throws Exception {
		Variant variant = value.value;
		Datatype dt = variant.getBinding().type();
		if(Datatypes.STRING.equals(dt)) {
			String s = (String)variant.getValue(Bindings.STRING);
			if(s.contains("\n")) {
				return "\"\"\"" + s + "\"\"\"";
			} else {
				return "\"" + s + "\"";		
			}
		} else if(Datatypes.BOOLEAN.equals(dt)) {
			Boolean i = (Boolean)variant.getValue(Bindings.BOOLEAN);
			return i ? "true" : "false";
		} else if(Datatypes.INTEGER.equals(dt)) {
			Integer i = (Integer)variant.getValue(Bindings.INTEGER);
			return i.toString();
		} else if(Datatypes.LONG.equals(dt)) {
			Long i = (Long)variant.getValue(Bindings.LONG);
			return i.toString();
		} else {
			byte[] data = variant.getBinding().serializer().serialize(variant.getValue());
			m.reset();
			m.update(data, 0, data.length);
			return "\"" + new BigInteger(1, m.digest()).toString(16) + "\"";
		}

	}

	//	void fixInstanceOf(TransferableGraph1 graph, ResourceInfo info) {
	//		Identity id = getIdentity(graph, info.resource);
	//		if(id == null) return;
	//		if(id.definition instanceof Internal) {
	//			Identity instanceOf = findExternal(graph, "http://www.simantics.org/Layer0-1.1/InstanceOf");
	//			Identity library = findExternal(graph, "http://www.simantics.org/Layer0-1.1/Library");
	//			info.statements.add(instanceOf.resource);
	//			info.statements.add(library.resource);
	//		}
	//	}

	public static String getExternalURI(TransferableGraph1 tg, External ext) {
		String name = ext.name;
		if(name.contains(" ")) name = name.replace(" ", "_").replaceAll("@", "_");//name = "\"" + name + "\"";
		int parentId = ext.parent;
		//if(parentId == 0) return ext.name;
		//		else {
		Identity id = getIdentity(tg, parentId);
		if(id.definition instanceof External) {
			return getExternalURI(tg, (External)id.definition) + "/" + name;
		} else if(id.definition instanceof Root) {
			Root root = (Root)id.definition;
			return "http:/" + root.name + "/" + name; 
		} else {
			return null;
		}
		//		}
	}

	public static String getExternalURI(TransferableGraph1 tg, int resource) {
		Identity id = getIdentity(tg, resource);
		if(id == null) return null;
		if(id.definition instanceof External) {
			External ext = (External)id.definition;
			return getExternalURI(tg, ext);
		}
		return null;
	}

	String rewritePredicateURI(TransferableGraph1 graph, int predicate) {
		
		String uri = getExternalURI(graph, predicate);
		if(uri == null) {
			ResourceInfo info = infos.get(predicate);
			if(info != null) return info.name;
			return "_";
		}
		
		for(String ontology : ontologies.keySet()) {
			if(uri.contains(ontology)) {
				String key = ontologies.get(ontology);
				uri = uri.replace(ontology, key);
				referencedOntologies.add(ontology);
			}
		}
		
		uri = uri.replace("/", ".");
		
		return uri;
		
	}

	void indent(int indent) {
		for(int i=0;i<indent;i++) output.append("  ");
	}
	
	void printBlank(TransferableGraph1 graph, String predicateURI2, ResourceInfo info, int indent) {

		if(info.hasURI) return;
		indent(indent);
		output.append(predicateURI2 + " " + info.name + "\n");

		if(info.owner < 0) {
			printURI(graph, info, false, indent);
		}
		
	}

	long longStm(int predicate, int object) {
		return (predicate<<32) | (object & 0xffffffffL); 
	}

	void addStatement(Map<String,Set<String>> statements, String predicate, String object) {
		Set<String> objects = statements.get(predicate);
		if(objects == null) {
			objects = new TreeSet<>();
			statements.put(predicate, objects);
		}
		objects.add(object);
	}

	void printURI(TransferableGraph1 graph, ResourceInfo info, boolean requireURI, int indent) {

		if(requireURI && !info.hasURI) return;

		Map<String,Set<String>> statements = new TreeMap<>();
		Identity consistsOf = findExternal(graph, "http://www.simantics.org/Layer0-1.1/ConsistsOf");
		TLongHashSet processed = new TLongHashSet();
		for(int i=0;i<info.owned.size();i+=2) {
			long stmId = longStm(info.owned.get(i), info.owned.get(i+1));
			processed.add(stmId);
		}
		
		TIntArrayList rawStatements = getStatements(graph, info.resource);
		for(int i=0;i<rawStatements.size();i+=2) {
			long stmId = longStm(rawStatements.get(i), rawStatements.get(i+1));
			if(!processed.add(stmId)) continue;
			if(consistsOf.resource == rawStatements.get(i)) continue;
			String predicateURI = rewritePredicateURI(graph, rawStatements.get(i));
			ResourceInfo objectInfo = infos.get(rawStatements.get(i+1));
			if(objectInfo == null) {
				String objectURI = rewritePredicateURI(graph, rawStatements.get(i+1));
				addStatement(statements, predicateURI, objectURI);
			} else {
				addStatement(statements, predicateURI, objectInfo.name);
			}
		}

		if(indent == 0) {
			if("ROOT".equals(info.name)) {
				output.append("ROOT=<http:/>");
			} else if (info.aliasURI != null) {
				output.append(info.name + " = <" + info.aliasURI + ">");
			} else {
				output.append(info.name);
			}
			Set<String> instanceOfs = statements.get("L0.InstanceOf");
			if(instanceOfs != null) {
				for(String instanceOf : instanceOfs) {
					output.append(" : " + instanceOf);		
				}
			}
			Set<String> subrelationOfs = statements.get("L0.SubrelationOf");
			if(subrelationOfs != null) {
				for(String subrelationOf : subrelationOfs) {
					output.append(" <R " + subrelationOf);		
				}
			}
			Set<String> inherits = statements.get("L0.Inherits");
			if(inherits != null) {
				for(String inherit : inherits) {
					output.append(" <T " + inherit);		
				}
			}
			output.append("\n");
		}

		if(info.newResource)
			output.append("  @L0.new\n");

		for(Map.Entry<String, Set<String>> entry : statements.entrySet()) {
			String predicate = entry.getKey();
			if("L0.InstanceOf".equals(predicate)) continue;
			if("L0.SubrelationOf".equals(predicate)) continue;
			if("L0.Inherits".equals(predicate)) continue;
			if("L0.PartOf".equals(predicate)) continue;
			Set<String> objects = entry.getValue();
			if(objects.size() == 1) {
				indent(indent+1);
				output.append(predicate + " " + objects.iterator().next() + "\n");	
			} else{
				indent(indent+1);
				output.append(predicate + "\n");	
				for(String object : objects) {
					indent(indent+1);
					output.append("  " + object + "\n");	
				}
			}
		}

		for(int i=0;i<info.owned.size();i+=2) {
			String predicateURI = rewritePredicateURI(graph, info.owned.get(i));
			ResourceInfo ownedInfo = infos.get(info.owned.get(i+1));
			printBlank(graph, predicateURI, ownedInfo, indent+1);
		}
		
	}

	void prettyPrint(Path input, Path output) throws Exception {

		System.out.format("Converting exported shared ontology%n\t" + input.toString() + "%nto bundle-compatible ontology%n\t" + output.toString());
		try (InputStream is = new BufferedInputStream(Files.newInputStream(input), 128*1024)) {
			DataInput dis = new DataInputStream(is);
			org.simantics.databoard.container.DataContainer container = 
					DataContainers.readFile(dis); 
			Binding binding = TransferableGraph1.BINDING;
			TransferableGraph1 graph = (TransferableGraph1)container.content.getValue(binding);
			prettyPrint(graph);
			Files.write(output, this.output.toString().getBytes());

		}

	}
	
	static Map<String,String> knownOntologies = new HashMap<>();
	
	static {
		knownOntologies.put("http://www.simantics.org/Layer0-1.1", "L0");
		knownOntologies.put("http://www.simantics.org/Layer0X-1.1", "L0X");
		knownOntologies.put("http://www.simantics.org/Modeling-1.2", "MOD");
		knownOntologies.put("http://www.simantics.org/Diagram-2.2", "DIA");
		knownOntologies.put("http://www.simantics.org/Structural-1.2", "STR");
		knownOntologies.put("http://www.simantics.org/Document-1.2", "DOC");
		knownOntologies.put("http://www.simantics.org/Documentation-1.2", "DOCU");
		knownOntologies.put("http://www.simantics.org/G2D-1.1", "G2D");
		knownOntologies.put("http://www.simantics.org/SelectionView-1.2", "SEL");
		knownOntologies.put("http://www.simantics.org/Viewpoint-1.2", "VP");
		knownOntologies.put("http://www.simantics.org/Image2-1.2", "IMAGE2");
		knownOntologies.put("http://www.simantics.org/GraphFile-0.1", "GRAPHFILE");
		knownOntologies.put("http://www.simantics.org/Project-1.2", "PROJECT");
		knownOntologies.put("http://www.semantum.fi/Simupedia-1.0", "SIMUPEDIA");
		knownOntologies.put("http://www.semantum.fi/SimupediaWorkbench-1.0", "SIMUPEDIA_WORKBENCH");
	}

	
	void prettyPrint(TransferableGraph1 graph) throws Exception {

		for(Identity id : graph.identities) {
			if(id.definition instanceof Internal) {
				Internal internal = (Internal)id.definition;
				Identity parent = TransferableGraphUtils.getIdentity(graph, internal.parent);
				if(parent.definition instanceof External) {
					String name = "BASE";
					ResourceInfo info = new ResourceInfo(true, name, id.resource);
					info.aliasURI = TransferableGraphUtils.getURI(graph, id.resource);
					info.newResource = true;
					infos.put(id.resource, info);
					for(Identity child : getChildren(graph, id)) {
						recurseURI(graph, child, name);
					}
				}
			} else if (id.definition instanceof External) {
				External ext = (External)id.definition;
				// Try to detect shared libraries
				if(ext.name.contains("@")) {
					
					int index = ext.name.indexOf('@');
					String prefix = ext.name.substring(0, index);
					int index2 = ext.name.indexOf('/', index);
					String ontology = index2 == -1 ? ext.name : ext.name.substring(0, index2);  
					String uri = TransferableGraphUtils.getURI(graph, id.resource);
					ontologies.put(uri, prefix);
					
				} else if (ext.name.contains("-")) {

					String uri = TransferableGraphUtils.getURI(graph, id.resource);
			        Matcher m = versionExtractPattern.matcher(uri);
			        if (m.matches()) {
			        	if(!ontologies.containsKey(uri)) {
							int index = ext.name.indexOf('-');
							String prefix = ext.name.substring(0, index);
							ontologies.put(uri, prefix);
			        	}
			        }

				}
				

				
			}
		}
		// Discover other resources
		TIntArrayList todo = new TIntArrayList();
		for(ResourceInfo info : infos.valueCollection())
			todo.add(info.resource);
		while(!todo.isEmpty()) {
			int resource = todo.removeAt(todo.size()-1);
			discoverBlank(graph, resource, todo);
		}
		for(ResourceInfo info : infos.valueCollection())
			discoverOwners(graph, info);
		//			for(ResourceInfo info : infos.valueCollection())
		//				fixInstanceOf(graph, info);
		for(ResourceInfo info : infos.valueCollection())
			if(info.owner >= 0) {
				ResourceInfo ownerInfo = infos.get(info.owner);
				ownerInfo.owned.add(info.ownerPredicate);
				ownerInfo.owned.add(info.resource);
			}

		TreeMap<String,ResourceInfo> order = new TreeMap<>();
		for(ResourceInfo info : infos.valueCollection())
			order.put(info.name, info);

		for(ResourceInfo info : order.values())
			printURI(graph, info, true, 0);

		for(ResourceInfo info : order.values())
			if(!info.hasURI && info.owner < 0)
				printURI(graph, info, false, 0);

		StringBuilder refs = new StringBuilder();
		for(String ontology : referencedOntologies) {
			String key = ontologies.get(ontology);
			refs.append(key + " = <" + ontology + ">\n");	
		}
		output.insert(0, refs.toString());
		
	}

	public static String print(TransferableGraph1 tg) throws Exception {
		StringBuilder b = new StringBuilder();
		new PrettyPrintTG(b).prettyPrint(tg);
		return b.toString();
	}

	public static void main(String[] args) throws Exception {
		if (args.length < 1) {
			System.out.println("Required arguments: <input .sharedOntology file> [<output .tg file>]");
		} else if (args.length < 2) {
			Path input = Paths.get(args[0]);
			Path output = input.getParent().resolve(input.getName(input.getNameCount()-1) + ".fixed");
			new PrettyPrintTG().prettyPrint(input, output);
		} else {
			new PrettyPrintTG().prettyPrint(Paths.get(args[0]), Paths.get(args[1]));
		}
	}

}