package ij.plugin;
import ij.*;
import ij.gui.GenericDialog;
import ij.process.*;
import ij.measure.Calibration;

/** This plugin implements the Image/Stacks/Tools/Grouped Z Project command. */

public class GroupedZProjector implements PlugIn {
    private static int method = ZProjector.AVG_METHOD;
    private int groupSize;
    
    public void run(String arg) {
        ImagePlus imp = IJ.getImage();
        int size = imp.getStackSize();
        if (size==1) {
            IJ.error("Z Project", "This command requires a stack");
            return;
        }
        if (imp.isHyperStack()) {
            new ZProjector().run("");
            return;
        }
        if (!showDialog(imp))
            return;
        ImagePlus imp2 = groupZProject(imp, method, groupSize);
        imp2.setCalibration(imp.getCalibration());
        Calibration cal = imp2.getCalibration();
        cal.pixelDepth *= groupSize;
        if (imp!=null)
            imp2.show();
    }
    
    public ImagePlus groupZProject(ImagePlus imp, int method, int groupSize) {
        if (method<0 || method>=ZProjector.METHODS.length)
            return null;
        int[] dim = imp.getDimensions();
        int projectedStackSize = imp.getStackSize()/groupSize;
        imp.setDimensions(1, groupSize, projectedStackSize);
        ZProjector zp = new ZProjector(imp);
        zp.setMethod(method);
        zp.setStartSlice(1);
        zp.setStopSlice(groupSize);
        zp.doHyperStackProjection(true);
        imp.setDimensions(dim[2], dim[3], dim[4]);

        ImagePlus zProjectorOutput = zp.getProjection();
        int[] zProjectDim = zProjectorOutput.getDimensions();
        for (int i=2; i<dim.length; i++) {
            if (dim[i] != 1)
                zProjectDim[i] = projectedStackSize;
            else
                zProjectDim[i] = 1;
        }
        // Fix dimensions for output ImagePlus
        zProjectorOutput.setDimensions(zProjectDim[2], zProjectDim[3], zProjectDim[4]);
        return zProjectorOutput;
    }
    
    boolean showDialog(ImagePlus imp) {
        int size = imp.getStackSize();
        GenericDialog gd = new GenericDialog("Z Project");
        gd.addChoice("Projection method:", ZProjector.METHODS, ZProjector.METHODS[method]);
        gd.addNumericField("Group size:", size, 0);
        String factors = "Valid factors: ";
        int i = 1, count = 0;
        while (i <= size && count<10) {
            if (size % i == 0) {
                count++; factors +=  " "+ i +",";
            }
            i++;
        }
        gd.setInsets(10,0,0);
        gd.addMessage(factors+"...");
        gd.showDialog();
        if (gd.wasCanceled())
            return false;
        method = gd.getNextChoiceIndex();
        groupSize = (int)gd.getNextNumber();
        if (groupSize<1 || groupSize>size || (size%groupSize)!=0) {
            IJ.error("ZProject", "Group size must divide evenly into the stack size.");
            return false;
        }
        return true;
    }
    
}