/**
 * This script creates a new composition with a blurred background effect.
 * It duplicates the selected footage, scales it to fit the composition,
 * applies a Gaussian Blur and Levels effect to the duplicated layer,
 * and renames the layers accordingly.
 */

// Get the active project
var project = app.project;
if (!project) {
    alert("No project open.");
} else {
    app.beginUndoGroup("Create Blurred Background");
    
    // Get the selected items
    var selectedItems = project.selection;
    if (selectedItems.length === 0) {
        alert("No footage selected.");
    } else {
        var footage = selectedItems[0];
    
        // Create a new composition
        var compWidth = 1920;
        var compHeight = 1080;
        var compDuration = footage.duration;
        var compFPS = footage.frameRate;
        var comp = project.items.addComp("Blurred Background Comp", compWidth, compHeight, 1, compDuration, compFPS);
    
        // Add the footage to the composition
        var layer = comp.layers.add(footage);
        // Scale to fit height
        var scaleFactor = (compHeight / footage.height) * 100;
        layer.transform.scale.setValue([scaleFactor, scaleFactor]);
        layer.transform.position.setValue([compWidth / 2, compHeight / 2]);
    
        // Duplicate the layer
        var duplicateLayer = layer.duplicate();
        duplicateLayer.moveBefore(layer);
    
        // Scale the duplicated layer to fill width
        var duplicateScaleFactor = (compWidth / footage.width) * 100;
        duplicateLayer.transform.scale.setValue([duplicateScaleFactor, duplicateScaleFactor]);
    
        // Add Gaussian Blur effect to duplicated layer
        var blurEffect = duplicateLayer.Effects.addProperty("ADBE Gaussian Blur 2");
        blurEffect.property("Blurriness").setValue(100);
    
        // Add Levels effect to duplicated layer
        var levelsEffect = duplicateLayer.property("Effects").addProperty("ADBE Easy Levels");
    
        // Rename the layers
        duplicateLayer.name = "Background Layer";
        layer.name = "Foreground Layer";
    
        // Reorder layers to ensure original layer is on top
        layer.moveToBeginning();
    
        // Open the new composition
        comp.openInViewer();
    
        app.endUndoGroup();
    }
}