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)

        self.name = name
        self.dim_names = []
        self._observers = {}
        self.current_data = None
        self.datasets = []
        self.sel_obj = dataset.Selection()
        
    def attach(self,observer,key):
        """Attach observer for selection updates"""
        if not self._observers.has_key(key):
            self._observers[key]=[]        
        if not observer in self._observers[key]:
            self._observers[key].append(observer)

    def detach(self,observer,key):
        """Detach observer for selection updates"""
        try:
            self._observers[key].remove(observer)
        except ValueError:
            pass

    def notify(self,key,modifier=None):
        """Notifies observers"""
        for observer in self._observers[key]:
            if modifier != observer:
                observer.update(key)

    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_update')

    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)

        for d in data:
            if isinstance(d, dataset.Dataset):
                self.add_dataset(d)
                self.data_tree_insert(it, d.get_name(), d)
            elif isinstance(d, plots.Plot):
#                self.add_view(d)
                self.data_tree_insert(it, d.get_title(), d)
                d.set_project(self)
                self.attach(d, 'selection_update')

    def data_tree_insert(self, parent, text, data):
        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)
        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