package net.yacy.interaction;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.net.URLEncoder;
import java.nio.charset.Charset;

import net.yacy.yacy;
import net.yacy.cora.document.ASCII;
import net.yacy.cora.protocol.RequestHeader;
import net.yacy.cora.protocol.http.HTTPClient;
import net.yacy.document.Document;
import net.yacy.document.TextParser;
import net.yacy.kelondro.data.meta.DigestURI;
import net.yacy.kelondro.logging.Log;
import net.yacy.search.Switchboard;

import org.htmlparser.Tag;
import org.htmlparser.Text;
import org.htmlparser.util.NodeList;
import org.htmlparser.visitors.NodeVisitor;

import de.anomic.http.server.ServerSideIncludes;


public class AugmentHtmlStream {

    static RequestHeader globalrequestHeader;

    /**
     * creates a NodeVisitor which assigns a unique ID to every node
     *
     * @return customized NodeVisitor
     */
    private static class VisitorAddUniqueID extends NodeVisitor {

        private int counter;

        public VisitorAddUniqueID() {
            this.setCounter(0);
        }

        @Override
        public void visitTag(Tag tag) {
            if (tag.getAttribute("id") == null) {
                this.setCounter(this.getCounter() + 1);
                tag.setAttribute("id", "\"sci" + this.getCounter() + "\"");
            }

            if (tag instanceof org.htmlparser.tags.LinkTag) {
                // Link
                Log.logInfo("AUGMENTATION", tag.getAttribute("href"));

                //LinkTag lt = (LinkTag)tag;

            }

        }

        @Override
        public void visitStringNode(Text string) {

        }

        public void setCounter(int counter) {
            this.counter = counter;
        }

        public int getCounter() {
            return this.counter;
        }

    }

    /**
     * creates a NodeVisitor which inspects the element if it contains useful
     * text
     *
     * @return customized NodeVisitor
     */
    private static class VisitorText extends NodeVisitor {

        private int counter;

        public VisitorText() {
            this.counter = 0;
        }

        @Override
        public void visitTag(Tag tag) {

//          tag.setText(tag.getText()+" <span>augmented</span>");

//          Node node = new org.htmlparser.nodes.TextNode(loadInternal("interactionparts/scibutton.html", globalrequestHeader));
//          NodeList nl = tag.getChildren();
//          nl.add (node);
//          tag.setChildren(nl);

        }

        @Override
        public void visitStringNode(Text string) {

//          if (string.getParent() != null) {
//
//              string.setText(string
//                      .getText()
//                      .replaceAll("und",
//                              "<a href=\"http://www.kit.edu/\" target=\"_blank\">KIT</a>"));
//
//
//          }
        }

        public void setCounter(int counter) {
            this.counter = counter;
        }

        public int getCounter() {
            return this.counter;
        }

    }

    /**
     * send web page to external REFLECT web service
     *
     * @return the web page with integrated REFLECT elements
     */
    private static String processExternal(String url, String fieldname,
            String data) throws IOException {
        final HTTPClient client = new HTTPClient();
        try {
            StringBuilder postdata = new StringBuilder();
            postdata.append("document=");
            postdata.append(URLEncoder.encode(data, "UTF-8"));
            InputStream in = new ByteArrayInputStream(postdata.toString()
                    .getBytes());
            byte[] result = client.POSTbytes(url, in, postdata.length());
            if (result != null) {
                return new String(result);
            }
        } finally {
            client.finish();
        }
        return null;
    }

    private static String loadInternal(String path, RequestHeader requestHeader) {
        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
        String realmProp = requestHeader.get(RequestHeader.AUTHORIZATION);
        ServerSideIncludes.writeContent(path, buffer, realmProp, "127.0.0.1", requestHeader); // TODO: ip
        return buffer.toString();
    }

    /**
     * add DOCTYPE if necessary
     *
     * @return the web page with a leading DOCTYPE definition
     */
    private static String processAddDoctype(String data) {

        String result = data;

        BufferedReader reader = new BufferedReader(new StringReader(data));

        try {
            String firstline = reader.readLine();

            if (firstline != null) {
                if (!firstline.startsWith("<!DOCTYPE")) {
                    result = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\">\n"
                            + data;
                }
            }
        } catch (IOException e1) {

        }

        return result;

    }

    /**
     * load snippet from resource text file
     *
     * @return text from resource text file
     */
    private static String loadPart(String part) {
        String result = "";
    try {
        BufferedReader in = new BufferedReader(new FileReader(yacy.homedir + File.separatorChar + "htroot"
                + File.separatorChar + "interaction" + File.separatorChar
                + "parts" + File.separatorChar + part));
        String str;
        while ((str = in.readLine()) != null) {
            result += str;
        }
        in.close();
    } catch (IOException e) {
    }

    return result;
    }

    public static StringBuffer process (StringBuffer data, Charset charset, DigestURI url, RequestHeader requestHeader) {
              
        String action =  requestHeader.get("YACYACTION");
        requestHeader.remove("YACYACTION");

        globalrequestHeader = requestHeader;
        
        Switchboard sb = Switchboard.getSwitchboard();

        boolean augmented = false;

        try {
            Log.logInfo("AUGMENTATION", url.getName());
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        String Doc = data.toString();

        // Send document to REFLECT (http://www.reflect.ws/REST_API.html)
        if (sb.getConfigBool("augmentation.reflect", false) == true) {
            try {

                Doc = processExternal("http://reflect.ws/REST/GetHTML",
                        "document", Doc);
                Log.logInfo("AUGMENTATION", "reflected " + url);
                augmented = true;
            } catch (Exception e) {

            }
        }

        // Add DOCTYPE if not present.
        // This is required for IE to render position:absolute correctly.

        if (sb.getConfigBool("augmentation.addDoctype", true) == true) {
            Doc = processAddDoctype(Doc);
            augmented = true;
        }


        if (sb.getConfigBool("augmentation.reparse", true) == true) {

            NodeList list = new NodeList();

            // Fill NodeList with parsed Document
            try {

                org.htmlparser.Parser par = new org.htmlparser.Parser();

                par.setInputHTML(Doc);

                list = par.parse(null);

                Log.logInfo ("AUGMENTATION", url.toString());

            } catch (Exception e) {
            }

            // Add Unique ID to every node element which has no id yet.
            // This allows consistent interaction between client (browser) and
            // back-end (data store) by providing "position awareness" in the
            // document.
            if (sb.getConfigBool("augmentation.reparse.adduniqueid", true) == true) {
                try {

                    NodeVisitor visitorAddUniqueID = new AugmentHtmlStream.VisitorAddUniqueID();
                    list.visitAllNodesWith(visitorAddUniqueID);

                } catch (Exception e) {
                }
            }

            // Inspect on text tags

            try {

                NodeVisitor visitorText = new AugmentHtmlStream.VisitorText();
                list.visitAllNodesWith(visitorText);

            } catch (Exception e) {
            }



            // System.out.println("Starting augmentation for " + url);
            // System.out.println("Content: " + Doc);

            if (!(list == null)) {

                // DOCUMENT IS MANIPULABLE BY HTML REWRITER

                // SO SEND IT TO YACY PARSER

                Document document = null;

                try {
                    final StringReader stringReader = new StringReader(Doc);
                    InputStream inputStream = new InputStream() {

                        @Override
                        public int read() throws IOException {
                            return stringReader.read();
                        }
                    };

                    document = Document.mergeDocuments(
                            url,
                            "text/html",
                            TextParser.parseSource(url, "text/html", null,
                                    data.length(), inputStream));

                } catch (Exception e) {

                }

                if (document != null) {

                    if (document.dc_format() == "text/html") {

//                        SCI_TITLE = document.dc_title();
//                        SCI_CREATOR = document.dc_creator();
//                        SCI_DESCRIPTION = document.dc_description();
//                        SCI_IDENTIFIER = document.dc_identifier();

                    }

                }


                // ADD AUGMENTED HEADER INFORMATION

                NodeList header = list.extractAllNodesThatMatch(
                        new org.htmlparser.filters.NodeClassFilter(
                                org.htmlparser.tags.HeadTag.class), true);

                org.htmlparser.util.SimpleNodeIterator iterHeader = header
                        .elements();

                while (iterHeader.hasMoreNodes()) {
                    org.htmlparser.tags.HeadTag ht = ((org.htmlparser.tags.HeadTag) iterHeader
                            .nextNode());

                    NodeList headchildren = ht.getChildren();

                    headchildren.add(new org.htmlparser.nodes.TextNode(loadInternal("env/templates/jqueryheader.template", requestHeader)));
                    headchildren.add(new org.htmlparser.nodes.TextNode("<script type='text/javascript'>"+loadInternal("interaction_elements/interaction.js", requestHeader)+"</script>"));
                    headchildren.add(new org.htmlparser.nodes.TextNode("<script type='text/javascript'>"+loadInternal("interaction_elements/interaction_metadata.js", requestHeader)+"</script>"));

                    augmented = true;

                    ht.setChildren(headchildren);
                }

                // ADD AUGMENTED BODY INFORMATION

                NodeList body = list.extractAllNodesThatMatch(
                        new org.htmlparser.filters.NodeClassFilter(
                                org.htmlparser.tags.BodyTag.class), true);

                org.htmlparser.util.SimpleNodeIterator iterBody = body
                        .elements();

                while (iterBody.hasMoreNodes()) {

                    org.htmlparser.tags.BodyTag bt = ((org.htmlparser.tags.BodyTag) iterBody
                            .nextNode());

                    NodeList bodychildren = bt.getChildren();

                    bodychildren.add(new org.htmlparser.nodes.TextNode(loadInternal("interaction_elements/OverlayInteraction.html?action="+action+"&urlhash="+ ASCII.String(url.hash()) +"&url="+url.toNormalform(false, true), requestHeader)));
                    
                    bodychildren.add(new org.htmlparser.nodes.TextNode(loadInternal("interaction_elements/Footer.html?action="+action+"&urlhash="+ ASCII.String(url.hash()) +"&url="+url.toNormalform(false, true), requestHeader)));

                    bt.setChildren(bodychildren);

                    augmented = true;

                }

                Doc = list.toHtml(true);

                augmented = true;

            } // not list = null

        } // reparse


        if (augmented) {

            return (new StringBuffer (Doc));
        } else {
            return (data);
        }
    }

}