package org.simantics.xml.data;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.Date;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.Attribute;
import javax.xml.stream.events.Characters;
import javax.xml.stream.events.EndElement;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;

import org.simantics.xml.sax.SchemaConversionBase;
import org.w3._2001.xmlschema.Annotated;
import org.w3._2001.xmlschema.ComplexType;
import org.w3._2001.xmlschema.Element;
import org.w3._2001.xmlschema.ExplicitGroup;
import org.w3._2001.xmlschema.Import;
import org.w3._2001.xmlschema.LocalComplexType;
import org.w3._2001.xmlschema.LocalElement;
import org.w3._2001.xmlschema.OpenAttrs;
import org.w3._2001.xmlschema.Schema;
import org.w3._2001.xmlschema.TopLevelElement;

/**
 * This class generates XML-file parsers based on bunch of XML data files. It is recommended to use schema based parser (org.simantics.xml.sax.SchemaConverter) if possible.
 * Parser generated by this class is not reliable...
 * 
 * @author luukkainen
 *
 */
public class XmlDataConverter {
	
	File outputPlugin;
	File conversionFile;
	List<File> inputFiles;
	
	String pluginName;
	
	private String[] header;
	
	public XmlDataConverter(List<File> inputFiles, File conversionFile, File outputPlugin) {
		if (inputFiles.size() == 0)
			throw new IllegalArgumentException("At least one input file must be given.");
		this.outputPlugin = outputPlugin;
		this.conversionFile = conversionFile;
		this.inputFiles = inputFiles;
		
		pluginName = outputPlugin.getName();
		
	}
	
	public void convert() throws IOException, XMLStreamException, JAXBException {
		
		init();
		doConvert();
		
		Map<Schema, File> fileMap = new HashMap<>();
		JAXBContext jc = JAXBContext.newInstance("org.w3._2001.xmlschema");
		Marshaller m = jc.createMarshaller();
		m.setProperty("jaxb.formatted.output", true);
		Set<String> filenames = new HashSet<>(); 
		for (Schema s : schemaMap.values()) {
			String name = s.getTargetNamespace();
			// Special case for XAML
			if (name.startsWith("clr-namespace:")) {
				name = name.substring("clr-namespace:".length());
				int i = name.indexOf(";assembly");
				if (i > 0)
					name = name.substring(0, i);
			}
			name = name.replaceAll("\\.", "_");
			name = name.replaceAll("/", "_");
			name = name.replaceAll(":", "_");
			name = name.replaceAll(";", "_");
			if (filenames.contains(name)) {
				int i = 2;
				while (filenames.contains(name+i)) {
					i++;
				}
				name = name+i;
			}
			filenames.add(name);
			File file = new File(outputPlugin.getAbsolutePath() + File.separator + name +".xsd");
			fileMap.put(s, file);
		}
		for (Schema s : schemaMap.values()) {
			for (OpenAttrs openAttrs : s.getIncludeOrImportOrRedefine()) {
				if (openAttrs instanceof Import) {
					Import import1 = (Import)openAttrs;
					Schema dep = schemaMap.get(import1.getNamespace());
					import1.setSchemaLocation(fileMap.get(dep).getName());
				}
			}
		}
		for (Schema s : schemaMap.values()) {
			File file = fileMap.get(s);
			m.marshal(s, file);
		}
		Schema rootSchema = schemaMap.values().iterator().next();
		DataSchemaConverter schemaConverter = new DataSchemaConverter(rootSchema,fileMap.get(rootSchema),conversionFile,outputPlugin);
		schemaConverter.setFileMap(fileMap);
		schemaConverter.setSchemaMap(schemaMap);
		schemaConverter.convert();
		
		
		header = null;
		schemaMap = null;
		elementMap = null;
	}
	
	protected void init()  throws IOException {
		
		header = new String[4];
		header[0] = "Generated with org.simantics.xml.sax XML data file converter";
		header[1] = "";
		header[2] = "File " + inputFiles.get(0).getAbsolutePath().replaceAll(Matcher.quoteReplacement("\\"), "/") + " , total file count: " + (inputFiles.size()) + "";
		header[3] = "Date " + new Date().toString();
		
		schemaMap = new HashMap<>();
		elementMap = new HashMap<>();
		attributeMap = new HashMap<>();
		elementNsMap = new HashMap<>();
	}
	
	Map<String, Schema> schemaMap = new LinkedHashMap<>();
	Map<Schema,Map<String,Element>> elementMap = new HashMap<>();
	Map<Element,String> elementNsMap = new HashMap<>();
	Map<Schema,Map<String,org.w3._2001.xmlschema.Attribute>> attributeMap = new HashMap<>();
	
	protected void doConvert() throws IOException, XMLStreamException, JAXBException {
		XMLInputFactory input = XMLInputFactory.newInstance();
		
		
		for (File inputFile : inputFiles) {
			XMLEventReader reader = input.createXMLEventReader(new FileInputStream(inputFile));
			convertFile(reader);
		}
		
	}
	
	private void convertFile(XMLEventReader reader) throws XMLStreamException {
		Deque<Element> elementStack = new ArrayDeque<>();
		while (reader.hasNext()) {
			XMLEvent event = reader.nextEvent();
			if (event.isStartElement()) {
				StartElement parseElement = event.asStartElement();
//				System.out.println("Start " + parseElement.getName());
				Element schemaElement = null;
				String currentNS = parseElement.getName().getNamespaceURI();
				Schema s = schemaMap.get(currentNS);
				String elementName = parseElement.getName().getLocalPart();
				if (s == null) {
					s = getOrCreateSchema(parseElement);
				} else {
					schemaElement = elementMap.get(s).get(elementName);
				}
				Element parentElement = elementStack.peek();
				
				boolean newElement = false;
				boolean sameNameSpace = true;
				
				if (parentElement != null) {
					String parentNs = elementNsMap.get(parentElement);
					sameNameSpace =currentNS.equals(parentNs);
					if (!sameNameSpace) {
						Schema ps = getOrCreateSchema(parentNs);
						addSchemaDependency(ps, s);
					}
						
				}
				if (schemaElement == null) {
					if (elementStack.isEmpty()) {
						schemaElement = new TopLevelElement();
						s.getSimpleTypeOrComplexTypeOrGroup().add(schemaElement);
					} else {
						schemaElement = new TopLevelElement();
						s.getSimpleTypeOrComplexTypeOrGroup().add(schemaElement);
					}
					schemaElement.setName(elementName);
					elementNsMap.put(schemaElement, currentNS);				
					
					
					elementMap.get(s).put(elementName, schemaElement);
					newElement = true;
				}
				if (parentElement != null) {
					ComplexType complexType = parentElement.getComplexType(); 
					ExplicitGroup choice = complexType.getChoice();
					if (choice == null) {
						choice = new ExplicitGroup();
						complexType.setChoice(choice);
						choice.setMaxOccurs("unbounded");
					}
					LocalElement localElement = new LocalElement();
					localElement.setRef(new QName(parseElement.getName().getNamespaceURI(), elementName));
					
					addElement(choice, new QName(SchemaConversionBase.SCHEMA_NS,"element"), localElement);
				}
				
				elementStack.push(schemaElement);
				
				Iterator<Attribute> attributeIterator = parseElement.getAttributes();
				
//				while (attributeIterator.hasNext()) {
//					Attribute attribute = attributeIterator.next();
//					System.out.println("Attribute " + attribute.getName() + " " + attribute.getValue());
//				}
				if (newElement) {
					LocalComplexType complexType = new LocalComplexType();
					schemaElement.setComplexType(complexType);
					attributeIterator = parseElement.getAttributes();
					while (attributeIterator.hasNext()) {
						Attribute attribute = attributeIterator.next();
						if ("http://www.w3.org/XML/1998/namespace".equals(attribute.getName().getNamespaceURI()))
							continue;
						addAttribute(attribute, complexType, currentNS);
					}
					
				} else {
					LocalComplexType complexType = schemaElement.getComplexType();
					attributeIterator = parseElement.getAttributes();
					Map<String,org.w3._2001.xmlschema.Attribute> currentAttributes = new HashMap<>();
					Iterator<Annotated> currentAttributeIterator = complexType.getAttributeOrAttributeGroup().iterator();
					while (currentAttributeIterator.hasNext()) {
						Annotated annotated = currentAttributeIterator.next();
						if (annotated instanceof org.w3._2001.xmlschema.Attribute) {
							org.w3._2001.xmlschema.Attribute schemaAttribute = (org.w3._2001.xmlschema.Attribute)annotated;
							String n = schemaAttribute.getName();
							if (n != null)
								currentAttributes.put(n, schemaAttribute);
						}
					}
					while (attributeIterator.hasNext()) {
						Attribute attribute = attributeIterator.next();
						if ("http://www.w3.org/XML/1998/namespace".equals(attribute.getName().getNamespaceURI()))
							continue;
						org.w3._2001.xmlschema.Attribute schemaAttribute = currentAttributes.get(attribute.getName().getLocalPart());
						if (schemaAttribute == null) {
							addAttribute(attribute, complexType, currentNS);
						} else {
							QName newType = getType(attribute.getValue());
							updateAttributeType(schemaAttribute, newType);
						}
						
					}
				}
				
			} else if (event.isEndElement()) {
				EndElement element = event.asEndElement();
//				System.out.println("End " + element.getName());
				elementStack.pop();
			} else if (event.isAttribute()) {
			
			} else if (event.isStartDocument()) {

			} else if (event.isEndDocument()) {
				
			} else if (event.isEntityReference()) {
			
			} else if (event.isCharacters()) {
				Characters characters = event.asCharacters();
//				if (!characters.isWhiteSpace())
//					System.out.println(characters.getData());
		    } else if (event.isNamespace()) {
		    
		    }
		}
	}
	
	private void updateAttributeType(org.w3._2001.xmlschema.Attribute schemaAttribute, QName newType) {
		
		QName currentType = schemaAttribute.getType();
		if (!newType.getLocalPart().equals(currentType.getLocalPart())) {
				
			
			if (currentType.getLocalPart().equals("integer") && newType.getLocalPart().equals("double")) {
				// change integer to double
				schemaAttribute.setType(newType);
			} else if (currentType.getLocalPart().equals("double") && newType.getLocalPart().equals("integer")) {
				// nothing to do, integer can be parsed as double
			} else if (!currentType.getLocalPart().equals("string")){
				schemaAttribute.setType(new QName(SchemaConversionBase.SCHEMA_NS, "string"));
			}
		}
	}
	
	private void addElement(ExplicitGroup choice, QName type, LocalElement localElement) {
		for (Object o  : choice.getParticle()) {
			JAXBElement<LocalElement> el = (JAXBElement<LocalElement>)o;
			if (el.getName().equals(type)) {
				QName ref = el.getValue().getRef();
				QName ref2 = localElement.getRef();
				if (ref != null) {
					if (ref.equals(ref2))
						return;
				} else if (el.getValue().getType().equals(localElement.getType()))
						return;	
			}
				
		}
		choice.getParticle().add(new JAXBElement<LocalElement>(type, LocalElement.class, null, localElement));
	}
	
	private void addSchemaDependency(Schema parentSchema, Schema schema) {
		for (OpenAttrs openAttrs : parentSchema.getIncludeOrImportOrRedefine()) {
			if (openAttrs instanceof Import) {
				Import import1 = (Import)openAttrs;
				if (import1.getNamespace().equals(schema.getTargetNamespace()))
					return;
			}
		}
		Import import1 = new Import();
		import1.setNamespace(schema.getTargetNamespace());
		parentSchema.getIncludeOrImportOrRedefine().add(import1);
	}
	
	private void addAttribute(Attribute attribute, ComplexType complexType, String currentNS) {
		if (attribute.getName().getNamespaceURI().length() == 0 || attribute.getName().getNamespaceURI().equals(currentNS)) {
			org.w3._2001.xmlschema.Attribute schemaAttribute = new org.w3._2001.xmlschema.Attribute();
			schemaAttribute.setName(attribute.getName().getLocalPart());
			schemaAttribute.setType(getType(attribute.getValue()));
			addAttribute(complexType, schemaAttribute);
		} else {
			{
				Schema schema = getOrCreateSchema(currentNS);
				Schema attrSchema = getOrCreateSchema(attribute.getName().getNamespaceURI());
				
				org.w3._2001.xmlschema.Attribute schemaAttribute = attributeMap.get(attrSchema).get(attribute.getName().getLocalPart());
				if (schemaAttribute == null) {
					schemaAttribute = new org.w3._2001.xmlschema.TopLevelAttribute();
					schemaAttribute.setName(attribute.getName().getLocalPart());
					schemaAttribute.setType(getType(attribute.getValue()));
					attrSchema.getSimpleTypeOrComplexTypeOrGroup().add(schemaAttribute);
					attributeMap.get(attrSchema).put(attribute.getName().getLocalPart(), schemaAttribute);
				}
				addSchemaDependency(schema, attrSchema);
				
			}
			{
				org.w3._2001.xmlschema.Attribute schemaAttribute = new org.w3._2001.xmlschema.Attribute();
				schemaAttribute.setRef(new QName(attribute.getName().getNamespaceURI(),attribute.getName().getLocalPart()));
				addAttribute(complexType, schemaAttribute);
			}
			
		}
	}
	
	private void addAttribute(ComplexType complexType, org.w3._2001.xmlschema.Attribute schemaAttribute) {
		if (schemaAttribute.getName() != null) {
			for (Annotated annotated : complexType.getAttributeOrAttributeGroup()) {
				if (annotated instanceof org.w3._2001.xmlschema.Attribute) {
					org.w3._2001.xmlschema.Attribute attr = (org.w3._2001.xmlschema.Attribute)annotated;
					if (schemaAttribute.getName().equals(attr.getName())) {
						updateAttributeType(attr, schemaAttribute.getType());
					}
				}
			}
		} else {
			for (Annotated annotated : complexType.getAttributeOrAttributeGroup()) {
				if (annotated instanceof org.w3._2001.xmlschema.Attribute) {
					org.w3._2001.xmlschema.Attribute attr = (org.w3._2001.xmlschema.Attribute)annotated;
					if (attr.getName() != null)
						continue;
					if (schemaAttribute.getRef().equals(attr.getRef())) {
						return;
					}
				}
			}
		}
		complexType.getAttributeOrAttributeGroup().add(schemaAttribute);
	}
	
	
	private QName getType(String value) {
		try {
			Integer.parseInt(value);
			return new QName(SchemaConversionBase.SCHEMA_NS, "integer");
		} catch (NumberFormatException e) {
			
		}
		
		try {
			Double.parseDouble(value);
			return new QName(SchemaConversionBase.SCHEMA_NS, "double");
		} catch (NumberFormatException e) {
			
		}
		if ("True".equals(value) || "False".equals(value))
			return new QName(SchemaConversionBase.SCHEMA_NS, "boolean");
		return new QName(SchemaConversionBase.SCHEMA_NS, "string");
		
	}
	
	private Schema getOrCreateSchema(StartElement parseElement) {
		return getOrCreateSchema(parseElement.getName().getNamespaceURI());
	}
	
	private Schema getOrCreateSchema(String ns) {
		if (ns == null)
			throw new IllegalArgumentException("Schema NS cannot be null.");
		Schema s = schemaMap.get(ns);
		if (s == null) {
			s = new Schema();
			s.setTargetNamespace(ns);
			schemaMap.put(ns, s);
			elementMap.put(s, new HashMap<String,Element>());
			attributeMap.put(s, new HashMap<String, org.w3._2001.xmlschema.Attribute>());
		}
		return s;
	}

}