PyQGIS composed Atlas generation

Question

I have some layers :

layer 1
layer 2
layer 3

and I have create styles for any labels layer using base rule styles and labels and I have create a template .qpt and I use atlas correct.

In my template I have dynamic labels with my values from attributes like name id and more.

Here my template :

On my style I have define specific $mapid for any style and layer.

Now I want to create a plugin where add automate layers styles and create composed Atlas generation.

First have a plugin window where the user can chooses layers from ToC.

Here the window :

Second I create the PyQGIS code where add style on chooses labels:

def run(self):
    layers = self.iface.legendInterface().layers()
    layer_list = []
    for layer in layers:
         layer_list.append(layer.name())
    self.dlg.comboBox_1_layer1.addItems(layer_list)
    self.dlg.comboBox_2_layer2.addItems(layer_list)
    self.dlg.comboBox_3_layer3.addItems(layer_list)
    self.dlg.show()
    result = self.dlg.exec_()
    if result:
        selectedLayerIndex1 = self.dlg.comboBox_1_layer1.currentIndex()
        selectedLayerIndex2 = self.dlg.comboBox_2_layer2.currentIndex()
        selectedLayerIndex3 = self.dlg.comboBox_3_layer3.currentIndex()
        selectedLayer1 = layers[selectedLayerIndex1]
        selectedLayer2 = layers[selectedLayerIndex2]
        selectedLayer3 = layers[selectedLayerIndex3]
        selectedLayer4 = layers[selectedLayerIndex4]
        selectedLayer5 = layers[selectedLayerIndex5]
        selectedLayer6 = layers[selectedLayerIndex6]
        a='/layer1.qml'
        b='/layer2.qml'
        c='/layer3.qml'
        test1=uri+a
        test2=uri+b
        test3=uri+c
        selectedLayer1.loadNamedStyle(test1)
        selectedLayer2.loadNamedStyle(test2)
        selectedLayer3.loadNamedStyle(test3)
        pass

This code work fine I have specific style for any chooses layer.

But I don't know how to start/add composed with my layers where I chooses and how to define my atlas with my template.

Any idea how to do that?