package org.apache.chainsaw.ant;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DirectoryScanner;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.types.FileSet;

/**
 * This Ant task creates the necessary .bat and .sh files required to run Chainsaw
 * on the commandline.  This task was created because it was getting VERY annoying
 * to constantly maintain 2 script files as the Jar file names kept changing during
 * the log4j 1.3 alpha stage, and as we (the Chainsaw developers) added dependencies
 * as we added functionality.
 * 
 * This task takes and outputLocation as a , and a set of FileSets which form the
 * basis of the classpath that is required to run Chainsaw.
 * 
 * @author psmith
 *
 */
public class CreateShellScripts extends Task {


    private String outputLocation;

    private Vector fileSets = new Vector();
    private String scriptType="";
    
    private Collection KNOWN_SCRIPT_TYPES = Arrays.asList(new String[] {"shell", "webstart"});

    public String getOutputLocation() {
        return outputLocation;
    }

    public void setOutputLocation(String outputLocation) {
        this.outputLocation = outputLocation;
    }

    public void execute() throws BuildException {
        super.execute();
        if(getScriptType().length()==0) {
            throw new BuildException("scriptType property has not been set");
        }else if (!KNOWN_SCRIPT_TYPES.contains(getScriptType())) {
            throw new BuildException("scriptType '"+ getScriptType() + "' is not one of then known types: " + KNOWN_SCRIPT_TYPES);
        }
        File outputLocationDir = new File(getOutputLocation());
        if(!outputLocationDir.exists()) {
            log("Creating director(ies) ->" + getOutputLocation());
            outputLocationDir.mkdirs();
        }
        Collection filenames = getFilenames();
        try {
            if (getScriptType().equals("shell")) {
                createUnixShellScript(outputLocationDir, filenames);
                createBatShellScript(outputLocationDir, filenames);
            }else {
                createJNLP(outputLocationDir, filenames);
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw new BuildException("Failed to create Scripts",e);
        }        
    }

    
    /**
     * Creates a JNLP file for launching Chainsaw
     * @param outputLocationDir
     * @param filenames
     * @throws IOException
     */
    private void createJNLP(File outputLocationDir, Collection filenames) throws IOException {
//        String templateName = CreateShellScripts.class.getPackage().toString().replace('.', '/')+"/chainsawWebStart.jnlp";
//        log("Using JNLP template: " + templateName);
        BufferedReader reader = new BufferedReader(new FileReader(new File("packaging/chainsawWebStart.jnlp")));

        // convert the file to a String
        StringBuffer buf = new StringBuffer(1024);
        String line;
        while((line=reader.readLine())!=null) {
            buf.append(line).append("\n");
        }
        
        StringBuffer jarBuf = new StringBuffer();
        
        /**
         * Good one Sun!  For some stupid reason, we MUST list the jar that contains the main-class
         * FIRST.  Why? Why? WHYYYYYYYYYYYYYYYYYY?
         * 
         * So, we sort a copied list and make sure that the chainsaw jar is first.
         */
        List list = new ArrayList(filenames);
        Collections.sort(list, new Comparator() {

            public int compare(Object o1, Object o2) {
                if(o1.toString().toLowerCase().indexOf("chainsaw")>-1) {
                    return -1;
                }else if(o2.toString().toLowerCase().indexOf("chainsaw")>-1) {
                    return 1;
                }else {
                    return 0;
                }
            }});
        for (Iterator iter = list.iterator(); iter.hasNext();) {
            String jar = (String) iter.next();
            jarBuf.append("\t<jar href=\"lib/"+jar + "\"/>\n");
        }
        // now replace the bits we want
        int jarStringLocation = buf.indexOf("@JARS@");
        buf.replace(jarStringLocation, jarStringLocation + 6, jarBuf.toString());
        
        File jnlp = new File(outputLocationDir, "chainsawWebStart.jnlp");
        Writer writer = new FileWriter(jnlp);
        writer.write(buf.toString());
        writer.close();
    }

    public void addFileSet(FileSet fileSet) {
        fileSets.add(fileSet);
    }

    private void createBatShellScript(File outputLocationDir, Collection filenames) throws IOException {
        File unixScript = new File(outputLocationDir, "chainsaw.bat");
        
        log("Creating Windows .bat script: " + unixScript.getAbsolutePath());
        
        Writer writer = new FileWriter(unixScript);
        writeExecutionLine(filenames, writer, ';');
        writer.close();
    }

    private void createUnixShellScript(File outputLocationDir, Collection fileNames) throws IOException {
        File unixScript = new File(outputLocationDir, "chainsaw.sh");
        
        log("Creating Unix script: " + unixScript.getAbsolutePath());
        
        Writer writer = new FileWriter(unixScript);
        writer.write("#!/bin/sh\n");
        writeExecutionLine(fileNames, writer, ':');
        writer.close();
    }

    
    private void writeExecutionLine(Collection fileNames, Writer writer, char jarSeparator) throws IOException {
        writer.write("java -classpath ");
        for (Iterator iter = fileNames.iterator(); iter.hasNext();) {
            String fileName = (String) iter.next();
            writer.write(fileName);
            if(iter.hasNext()) {
                writer.write(jarSeparator);
            }
        }
        writer.write(" org.apache.log4j.chainsaw.LogUI" );
        writer.write("\n");
    }

    private Collection getFilenames() {
        List jars = new ArrayList();
        for (Iterator iter = fileSets.iterator(); iter.hasNext();) {
            FileSet fileSet = (FileSet) iter.next();
            DirectoryScanner ds = fileSet.getDirectoryScanner(getProject()); // 3
            String[] includedFiles = ds.getIncludedFiles();
            for (int i = 0; i < includedFiles.length; i++) {
                String filename = includedFiles[i].replace('\\', '/'); // 4
                filename = filename.substring(filename.lastIndexOf("/") + 1);
                // if (foundLocation==null && file.equals(filename)) {
                // File base = ds.getBasedir(); // 5
                // File found = new File(base, includedFiles[i]);
                // foundLocation = found.getAbsolutePath();
                // }
                jars.add(filename);
            }
        }
        return jars;
    }

    public String getScriptType() {
        return scriptType;
    }

    public void setScriptType(String scriptType) {
        this.scriptType = scriptType.toLowerCase();
    }

}