/**
This plugin, written by Jon Harmon, implements the File/Open Next command.
It opens the "next" image in a directory, where "next" can be the
succeeding or preceeding image in the directory list.
Press shift-o to open the succeeding image or 
alt-shift-o to open the preceeding image.
It can leave the previous file open, or close it.
You may contact the author at Jonathan_Harman at yahoo.com
This code was modified from Image_Browser by Albert Cardona
*/

package ij.plugin;
import ij.*;
import ij.io.*;
import ij.gui.*;
import java.io.File;

public class NextImageOpener implements PlugIn {

    boolean forward = true; // default browse direction is forward
    boolean closeCurrent = true; //default behavior is to close current window
    ImagePlus imp0;
    
    public void run(String arg) {
        /* get changes to defaults */
        if (arg.equals("backward") || IJ.altKeyDown()) forward = false;
        if (arg.equals("backwardsc")) {
            forward = false;
            closeCurrent = false;
        }
        if (arg.equals("forwardsc")) {
            forward = true;
            closeCurrent = false;
        }
                
        // get current image; displays error and aborts if no image is open
        imp0 = IJ.getImage();
        // get current image directory
        String currentPath = getDirectory(imp0);
        if (IJ.debugMode) IJ.log("OpenNext.currentPath:" + currentPath);
        if (currentPath==null) {
            IJ.error("Next Image", "Directory information for \""+imp0.getTitle()+"\" not found.");
            return;
        }
        // get the next name (full path)
        //long start = System.currentTimeMillis();
        String nextPath = getNext(currentPath, getName(imp0), forward);
        //IJ.log("time: "+(System.currentTimeMillis()-start));
        if (IJ.debugMode) IJ.log("OpenNext.nextPath:" + nextPath);
        // open
        if (nextPath != null) {
            String rtn = open(nextPath);
            if (rtn==null)
                open(getNext(currentPath, (new File(nextPath)).getName(), forward));
        }
    }
    
    String getDirectory(ImagePlus imp) {
        FileInfo fi = imp.getOriginalFileInfo();
        if (fi==null) return null;
        String dir = fi.openNextDir;
        if (dir==null) dir = fi.directory;
        return dir;
    }

    String getName(ImagePlus imp) {
        String name = imp.getTitle();
        FileInfo fi = imp.getOriginalFileInfo();
        if (fi!=null) {
            if (fi.openNextName!=null)
                name = fi.openNextName;
            else if (fi.fileName!=null)
                name = fi.fileName;
        }
        return name;
    }
    
    String open(String nextPath) {
        ImagePlus imp2 = IJ.openImage(nextPath);
        if (imp2==null) return null;
        String newTitle = imp2.getTitle();
        if (imp0.changes) {
            String msg;
            String name = imp0.getTitle();
            if (name.length()>22)
                msg = "Save changes to\n" + "\"" + name + "\"?";
            else
                msg = "Save changes to \"" + name + "\"?";
            YesNoCancelDialog d = new YesNoCancelDialog(imp0.getWindow(), "ImageJ", msg);
            if (d.cancelPressed())
                return "Canceled";
            else if (d.yesPressed()) {
                FileSaver fs = new FileSaver(imp0);
                if (!fs.save())
                    return "Canceled";
            }
            imp0.changes = false;
        }
        if (imp2.isComposite() || imp2.isHyperStack()) {
            imp2.show();
            imp0.close();
            imp0 = imp2;
        } else {
            imp0.setStack(newTitle, imp2.getStack());
            imp0.setCalibration(imp2.getCalibration());
            imp0.setFileInfo(imp2.getOriginalFileInfo());
            imp0.setProperty ("Info", imp2.getProperty ("Info"));
            imp0.setOverlay(imp2.getOverlay());
            ImageWindow win = imp0.getWindow();
            if (win!=null) win.repaint();
        }
        return "ok";
    }

    /** gets the next image name in a directory list */
    String getNext(String path, String imageName, boolean forward) {
        File dir = new File(path);
        if (!dir.isDirectory()) return null;
        String[] names = dir.list();
        ij.util.StringSorter.sort(names);
        int thisfile = -1;
        for (int i=0; i<names.length; i++) {
            if (names[i].equals(imageName)) {
                thisfile = i;
                break;
            }
        }
        if (IJ.debugMode) IJ.log("OpenNext.thisfile:" + thisfile);
        if(thisfile == -1) return null;// can't find current image
        
        // make candidate the index of the next file
        int candidate = thisfile + 1;
        if (!forward) candidate = thisfile - 1;
        if (candidate<0) candidate = names.length - 1;
        if (candidate==names.length) candidate = 0;
        // keep on going until an image file is found or we get back to beginning
        while (candidate!=thisfile) {
            String nextPath = path + names[candidate];
            if (IJ.debugMode) IJ.log("OpenNext: "+ candidate + "  " + names[candidate]);
            File nextFile = new File(nextPath);
            boolean canOpen = true;
            if (names[candidate].startsWith(".") || nextFile.isDirectory())
                canOpen = false;
            if (canOpen) {
                Opener o = new Opener();
                int type = o.getFileType(nextPath);
                if (type==Opener.UNKNOWN || type==Opener.JAVA_OR_TEXT
                ||  type==Opener.ROI ||  type==Opener.TEXT)
                    canOpen = false;
            }
            if (canOpen)
                    return nextPath;
            else {// increment again
                if (forward)
                    candidate = candidate + 1;
                else
                    candidate = candidate - 1;
                if (candidate<0) candidate = names.length - 1;
                if (candidate == names.length) candidate = 0;
            }
            
        }
        if (IJ.debugMode) IJ.log("OpenNext: Search failed");
        return null;
    }

}