/**
 *
 */
package de.intevation.gnv.artifacts;

import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import javax.xml.xpath.XPathConstants;

import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import de.intevation.artifactdatabase.Config;
import de.intevation.artifactdatabase.DefaultArtifact;
import de.intevation.artifactdatabase.XMLUtils;
import de.intevation.artifacts.ArtifactFactory;
import de.intevation.artifacts.ArtifactNamespaceContext;
import de.intevation.artifacts.CallContext;
import de.intevation.artifacts.CallMeta;
import de.intevation.gnv.artifacts.context.GNVArtifactContext;
import de.intevation.gnv.state.DefaultInputData;
import de.intevation.gnv.state.InputData;
import de.intevation.gnv.state.InputValue;
import de.intevation.gnv.state.OutputMode;
import de.intevation.gnv.state.OutputState;
import de.intevation.gnv.state.State;
import de.intevation.gnv.state.StateFactory;
import de.intevation.gnv.state.exception.StateException;
import de.intevation.gnv.transition.Transition;
import de.intevation.gnv.transition.TransitionFactory;
import de.intevation.gnv.utils.ArtifactXMLUtilities;

/**
 * @author Tim Englich <tim.englich@intevation.de>
 * 
 */
public abstract class GNVArtifactBase extends DefaultArtifact {
    /**
     * the logger, used to log exceptions and additonaly information
     */
    private static Logger log = Logger.getLogger(GNVArtifactBase.class);
    /**
     * The UID of this Class
     */
    private static final long serialVersionUID = -8907096744400741458L;

    /**
     * The Identifier for the Replacement of the Artifactname
     */
    public static final String XPATH_IDENTIFIER_REPLACE = "IDENTIFIER";

    /**
     * The XPATH to the XML-Fragment that should be used for the Configuration
     */
    public static final String XPATH_ARTIFACT_CONFIGURATION = "/artifact-database/artifacts/artifact[@name='"
                                                              + XPATH_IDENTIFIER_REPLACE
                                                              + "']";

    /**
     * The current State
     */
    protected State current = null;

    /**
     * The States that can be used
     */
    protected Map<String, State> states = null;
    
    /**
     * The Transitions which can switch between the different States.
     */
    protected Collection<Transition> transitions = null;

    /**
     * The Name of the Artifact
     */
    protected String name = null;

    private ArtifactXMLUtilities xmlUtilities = new ArtifactXMLUtilities();

    /**
     * Constructor
     */
    public GNVArtifactBase() {
        super();
    }

    /**
     * @see de.intevation.artifactdatabase.DefaultArtifact#advance(org.w3c.dom.Document,
     *      de.intevation.artifacts.CallContext)
     */
    @Override
    public Document advance(Document target, CallContext context) {
        log.debug("GNVArtifactBase.advance");
        Document result = XMLUtils.newDocument();
        try {
            if (this.current != null) {
                String stateName = this.readStateName(target);
                log.debug("Statename: " + stateName);
                if (this.isStateCurrentlyReachable(stateName)) {
                    try {
                        State nextStep = this.states
                                .get(stateName);
                        // 1.Ergebnisse Berechnen
                        this.current.advance(super.identifier, context.getMeta());
                        // 2. Ergebnisse �bergeben
                        nextStep.putInputData(this.current.getInputData(), 
                                              super.identifier);
                        // 3. Umschalten auf neue Transistion
                        this.current = nextStep;
                        
                        // 4. Initialisieren des n�chsten Schrittes == Laden der Daten
                        this.current.initialize(super.identifier, context.getMeta());
                        
                        result = new ArtifactXMLUtilities()
                                .createSuccessReport("Advance success",
                                        XMLUtils.newDocument());
                    } catch (StateException e) {
                        log.error(e, e);
                        result = new ArtifactXMLUtilities()
                                .createExceptionReport(e
                                        .getLocalizedMessage(), XMLUtils
                                        .newDocument());
                    }
                } else {
                    String msg = "Transitions�bergang wird nicht unterst�tzt.";
                    log.error(msg);
                    result = new ArtifactXMLUtilities().createExceptionReport(
                            msg, XMLUtils.newDocument());
                }
            } else {
                String msg = "Kein State aktiviert.";
                log.error(msg);
                result = new ArtifactXMLUtilities().createExceptionReport(msg,
                        XMLUtils.newDocument());
            }
        } catch (Exception e) {
            log.error(e, e);
            result = new ArtifactXMLUtilities().createExceptionReport(e
                    .getLocalizedMessage(), XMLUtils.newDocument());
        }
        return result;
    }
    
    
    private boolean isStateCurrentlyReachable(String stateid){
        log.debug("GNVArtifactBase.isStateCurrentlyReachable "+stateid);
        Iterator<Transition> it = this.transitions.iterator();
        String from = this.current.getID();
        while (it.hasNext()){
            Transition transition = it.next();
            if (transition.getFrom().equals(from)){
                if (transition.getTo().equals(stateid) && transition.isValid(this.current)){
                    return true;
                }
            }
        }
        return false;
    }
    
    public Document initialize (CallContext context) {
        Document result = XMLUtils.newDocument();
        try {
            this.current.initialize(super.identifier, context.getMeta());
            result = new ArtifactXMLUtilities()
            .createSuccessReport("Initialize success",
                    XMLUtils.newDocument());
        } catch (StateException e) {
            log.error(e,e);
            result = new ArtifactXMLUtilities().createExceptionReport(e
                    .getLocalizedMessage(), XMLUtils.newDocument());
        }
        return result;
    }

    protected String readStateName(Document document) {
        String returnValue = Config.getStringXPath(document,
                "action/target/@name");
        return returnValue;
    }

    protected Node getConfigurationFragment(Document document) {
        log.debug("GNVArtifactBase.getConfigurationFragment");
        String xpathQuery = XPATH_ARTIFACT_CONFIGURATION.replaceAll(
                XPATH_IDENTIFIER_REPLACE, this.name);
        log.debug(xpathQuery);
        
        Element configurationNode = (Element)Config.getNodeXPath(document, xpathQuery);
        
        String link = configurationNode.getAttribute("xlink:href");
        if (link != null ){
            String absolutFileName = Config.replaceConfigDir(link);
            configurationNode = (Element)new ArtifactXMLUtilities().readConfiguration(absolutFileName);
        }
        
        return configurationNode;
    }

    /**
     * @see de.intevation.artifactdatabase.DefaultArtifact#feed(org.w3c.dom.Document,
     *      de.intevation.artifacts.CallContext)
     */
    @Override
    public Document feed(Document target, CallContext context) {
        log.debug("GNVArtifactBase.feed");
        Document result = XMLUtils.newDocument();
        try {
            if (this.current != null) {
                Collection<InputData> inputData = this.parseInputData(target,
                                                                      "/action/data/input");
                if (!inputData.isEmpty()){
                    this.current.putInputData(inputData, super.identifier);
                    result = new ArtifactXMLUtilities().createSuccessReport(
                            "Feed success", XMLUtils.newDocument());
                }else{
                    String msg = "No Inputdata given. Please select at least one Entry.";
                    log.warn(msg);
                    result = new ArtifactXMLUtilities().createExceptionReport(msg,
                            XMLUtils.newDocument());
                }
            } else {
                String msg = "No State instantiated";
                log.warn(msg);
                result = new ArtifactXMLUtilities().createExceptionReport(msg,
                        XMLUtils.newDocument());
            }
        } catch (StateException e) {
            log.error(e, e);
            result = new ArtifactXMLUtilities().createExceptionReport(e
                    .getLocalizedMessage(), XMLUtils.newDocument());
        }
        return result;
    }

    /**
     * @see de.intevation.artifactdatabase.DefaultArtifact#setup(java.lang.String,
     *      java.lang.Object)
     */
    @Override
    public void setup(String identifier, ArtifactFactory factory, Object context) {
        log.debug("GNVArtifactBase.setup");
        super.setup(identifier, factory, context);

        Object localContext = context;
        if (context instanceof CallContext) {
            localContext = ((CallContext) context).globalContext();

        }

        if (localContext instanceof GNVArtifactContext) {
            GNVArtifactContext gnvContext = (GNVArtifactContext) localContext;
            Document doc = gnvContext.getConfig();
            Node artifactNode = this.getConfigurationFragment(doc);
                        
            NodeList stateList = Config.getNodeSetXPath(artifactNode,
                    "states/state");
            this.states = new HashMap<String, State>(stateList
                    .getLength());
            for (int i = 0; i < stateList.getLength(); i++) {
                State tmpState = StateFactory.getInstance()
                        .createState(stateList.item(i));
                if (tmpState != null) {
                    this.states.put(tmpState.getID(), tmpState);
                    if (this.current == null) {
                        this.current = tmpState;
                    }
                }
            }
            
            NodeList transitionList = Config.getNodeSetXPath(artifactNode,
            "states/transition");
            this.transitions = new ArrayList<Transition>(transitionList.getLength());
            for (int i = 0; i < transitionList.getLength(); i++) {
                Transition tmpTransition = TransitionFactory.getInstance()
                        .createTransition(transitionList.item(i));
                if (tmpTransition != null) {
                    this.transitions.add(tmpTransition);
                }
            }

        }
    }
    
    

    protected Document createDescibeOutput(CallMeta callMeta, String uuid, boolean incudeUI) {
        log.debug("GNVArtifactBase.createDescibeOutput");
        Document document = XMLUtils.newDocument();
        Element rootNode = this.createRootNode(document);
        this.createHeader(rootNode, document, "describe");
        this.createOutputs(rootNode, document);
        this.createCurrentState(rootNode, document);
        this.createReachableStates(rootNode, document);
        this.createModel(rootNode, document);
        if (incudeUI){
            this.createUserInterface(rootNode, document, callMeta, uuid);
        }
        return document;
    }
    
    protected boolean getIncludeUIFromDocument(Document document){
        String value = Config.getStringXPath(document, "action/include-ui");
        boolean includeUI = false;
        if (value != null){
            includeUI = Boolean.parseBoolean(value);
        }
        return includeUI;
    }

    protected Element createRootNode(Document document) {
        Element rootNode = xmlUtilities.createArtifactElement(document,
                "result");
        document.appendChild(rootNode);
        return rootNode;
    }

    protected void createHeader(Element parent, Document document,
                                String documentType) {
        Element typeNode = xmlUtilities.createArtifactElement(document, "type");
        typeNode.setAttribute("name", documentType);
        parent.appendChild(typeNode);

        Element uuidNode = xmlUtilities.createArtifactElement(document, "uuid");
        uuidNode.setAttribute("value", super.identifier);
        parent.appendChild(uuidNode);

        Element hashNode = xmlUtilities.createArtifactElement(document, "hash");
        hashNode.setAttribute("value", this.hash());
        parent.appendChild(hashNode);
    }

    protected void createReachableStates(Element parent, Document document) {
        Element stateNode = xmlUtilities.createArtifactElement(document,
                "reachable-states");
        if (this.current != null) {
            Iterator<Transition> transitions = this.transitions.iterator();
            while (transitions.hasNext()) {
                Transition tmpTransition = transitions.next();
                if (tmpTransition.getFrom().equals(current.getID()) && 
                    tmpTransition.isValid(this.current)){
                    Element currentNode = xmlUtilities.createArtifactElement(
                            document, "state");
                    currentNode.setAttribute("name", tmpTransition.getTo());
                    log.debug("Reachable State: " + tmpTransition.getTo());
                    currentNode.setAttribute("description", 
                                             this.states.get(tmpTransition.getTo())
                                                             .getDescription());
                    stateNode.appendChild(currentNode);
                }
            }
        }
        parent.appendChild(stateNode);
    }

    protected void createCurrentState(Element parent, Document document) {
        Element stateNode = xmlUtilities.createArtifactElement(document,
                "state");
        stateNode.setAttribute("name", this.current.getID());
        stateNode.setAttribute("description", this.current.getDescription());
        parent.appendChild(stateNode);
    }

    protected void createModel(Element parent, Document document) {
        Element modelNode = xmlUtilities.createArtifactElement(document,
                "model");
        if (this.current != null) {
            Collection<InputValue> inputValues = this.current
                    .getRequiredInputValues();
            if (inputValues != null) {
                Iterator<InputValue> it = inputValues.iterator();
                while (it.hasNext()) {
                    InputValue inputValue = it.next();
                    Element inputNode = xmlUtilities.createArtifactElement(
                            document, "input");
                    inputNode.setAttribute("name", inputValue.getName());
                    inputNode.setAttribute("type", inputValue.getType());
                    modelNode.appendChild(inputNode);
                }
            }
        }
        parent.appendChild(modelNode);
    }

    protected void createUserInterface(Element parent, Document document,
                                       CallMeta callMeta, String uuid) {
        Element uiNode = xmlUtilities.createArtifactElement(document, "ui");

        if (this.current != null) {
            this.current.describe(document, uiNode, callMeta, uuid);
        }

        parent.appendChild(uiNode);
    }

    protected void createOutputs(Element parent, Document document) {
        log.debug("GNVArtifactBase.createOutputs");
        Element outputsNode = xmlUtilities.createArtifactElement(document,
                "outputs");
        if (this.current instanceof OutputState) {
            Collection<OutputMode> outputModes = ((OutputState) this.current)
                    .getOutputModes();
            if (outputModes != null) {
                Iterator<OutputMode> it = outputModes.iterator();
                while (it.hasNext()) {
                    OutputMode outputMode = it.next();
                    log.debug("Write Outputnode for " + outputMode.toString());
                    Element outputModeNode = xmlUtilities
                            .createArtifactElement(document, "output");
                    outputModeNode.setAttribute("name", outputMode.getName());
                    outputModeNode.setAttribute("description", outputMode
                            .getDescription());
                    outputModeNode.setAttribute("mime-type", outputMode
                            .getMimeType());
                    outputsNode.appendChild(outputModeNode);

                    Collection<InputValue> inputParameters = outputMode
                            .getInputParameters();
                    if (inputParameters != null) {
                        Element inputParametersNode = xmlUtilities
                                .createArtifactElement(document, "parameter");
                        outputModeNode.appendChild(inputParametersNode);
                        Iterator<InputValue> it2 = inputParameters.iterator();
                        while (it2.hasNext()) {
                            InputValue inputValue = it2.next();
                            Element inputParameterNode = xmlUtilities
                                    .createArtifactElement(document,
                                            "parameter");
                            inputParametersNode.appendChild(inputParameterNode);
                            inputParameterNode.setAttribute("name", inputValue
                                    .getName());
                            inputParameterNode.setAttribute("type", inputValue
                                    .getType());
                            inputParameterNode.setAttribute("value", inputValue
                                    .getDefaultValue());
                        }
                    }
                }
            } else {
                log.warn("No Outputmodes given.");
            }
        }
        parent.appendChild(outputsNode);
    }

    protected Collection<InputData> parseInputData(Document document,
                                                   String xPath) {
        log.debug("GNVArtifactBase.parseInputData");
        HashMap<String, InputData> returnValue = null;

        log.debug(new ArtifactXMLUtilities().writeDocument2String(document));

        NodeList inputElemets = (NodeList) XMLUtils.xpath(document, xPath,
                XPathConstants.NODESET, ArtifactNamespaceContext.INSTANCE);// Config.getNodeSetXPath(document,
                                                                           // "");
        if (inputElemets != null) {
            returnValue = new HashMap<String, InputData>(inputElemets
                    .getLength());
            for (int i = 0; i < inputElemets.getLength(); i++) {
                Element inputDataNode = (Element)inputElemets.item(i);
                String name = inputDataNode.getAttribute("name");
                String value = inputDataNode.getAttribute("value");

                if (returnValue.containsKey(name)) {
                    InputData inputData = returnValue.get(name);
                    inputData.concartValue(value);
                    log.debug(inputData.toString());
                    returnValue.put(name, inputData);
                } else {
                    InputData inputData = new DefaultInputData(name, value);

                    returnValue.put(name, inputData);
                }
            }
        }
        return returnValue.values();
    }

    /**
     * @see de.intevation.artifactdatabase.DefaultArtifact#out(org.w3c.dom.Document,
     *      java.io.OutputStream, de.intevation.artifacts.CallContext)
     */
    @Override
    public void out(Document format, OutputStream outputStream,
                    CallContext context) throws IOException {
        log.debug("TGNVArtifactBase.out");
        try {

            if (current != null && current instanceof OutputState) {
                ((OutputState) current)
                        .out(format, this.parseInputData(
                                format, "/action/out/params/input"),
                                outputStream, super.identifier, context.getMeta());
            }
        } catch (StateException e) {
            log.error(e, e);
            throw new IOException(e.getMessage());
        }
    }

    protected String readOutputType(Document document) {
        String value = Config.getStringXPath(document, "action/out/@name");
        return value;
    }
}