import scipy
import gobject
import gtk
from system import dataset, plots

class Project:
    def __init__(self,name="Testing"):
        self.data_tree = gtk.TreeStore(gobject.TYPE_STRING, 
                                       gobject.TYPE_STRING, 
                                       gobject.TYPE_PYOBJECT,gobject.TYPE_STRING,gobject.TYPE_STRING)

        self.name = name
        self.dim_names = []
        self._selection_observers = []
        self.current_data = None
        self.datasets = []
        self.sel_obj = dataset.Selection()
        
    def notify_selection_listeners(self):
        """Notifies observers"""
        for observer in self._selection_observers:
            observer.selection_changed(self.get_selection())

    def set_selection(self,dim_name,selection):
        """Sets a current selection and notify observers"""
        self.sel_obj.current_selection[dim_name] = set(selection)
        self.notify_selection_listeners()

    def get_selection(self):
        """Returns the current selection object"""
        return self.sel_obj.current_selection
 
    def get_data_iter(self, obj):
        """Retuns an iterator to data."""
        retval = [None]
        def is_obj(m, p, i, d):
            if obj == m.get_value(i, 2):
                d.append(i)
                return True

        self.data_tree.foreach(is_obj, retval)
        return retval[-1]

    def add_data(self, parent, data, fun='Function'):
        """Adds a set of data and plots to the navigator.

        This method is usually called after a Function in a workflow
        has finished and returns its output."""
        
        parent_iter = self.get_data_iter(parent)

        it = self.data_tree_insert(parent_iter, fun, None, "grey","black")

        for d in data:
            if isinstance(d, dataset.Dataset):
                self.add_dataset(d)
                self.data_tree_insert(it, d.get_name(), d, "white", "blue")
            elif isinstance(d, plots.Plot):
                self.data_tree_insert(it, d.get_title(), d, "white", "dark green")
                d.set_selection_listener(self.set_selection)
                self._selection_observers.append(d)

    def data_tree_insert(self, parent, text, data, bgcolour,fontcolour):
        tree = self.data_tree
        it = tree.append(parent)
        tree.set_value(it, 0, text)
        tree.set_value(it, 1, type(data))
        tree.set_value(it, 2, data)
        tree.set_value(it, 3, bgcolour)
        tree.set_value(it, 4, fontcolour)
        return it

    def add_dataset(self,dataset):
        """Appends a new Dataset to the project."""
        self.datasets.append(dataset)
        for dim_name in dataset.get_all_dims():
            if dim_name not in self.dim_names:
                self.dim_names.append(dim_name)
                self.sel_obj.current_selection[dim_name] = set()

        
    def object_at(self, path):
        "Returns the object at a given path in the tree."
        iter = self.get_iter(path)
        object = self.get_value(iter, 2)
        if object:
            object.show()
        return object

    def set_current_data(self, obj):
        self.current_data = obj