import panel as pn
import param
from collections import namedtuple
from functools import reduce

class ContextManager:
    def __init__(self, df):
        self.df = df
        self.df_widget = pn.widgets.Tabulator(
            df, 
            page_size=9,
            show_index=False,
            layout='fit_columns',
            hidden_columns=['imagesrc'],
            sizing_mode='stretch_both'
        )

        self.df_widget.disabled = True
        self.df_widget.param.watch(self.update_grid_box_state, 'page')
        self.df_widget.on_click(self.update_grid_box_state)
        
        page = self.df.head(9).imagesrc.tolist()
        base_url = "https://ringsdb.com"
        imgs = [pn.pane.PNG(base_url+i) for i in page]
        self.box = pn.GridBox(
            *imgs, 
            ncols=3, 
            nrows=3,
            sizing_mode='stretch_width',
            max_width=525
        )
        Param = namedtuple('Param', ['new'])
        self.filters = {
            
        }
        self.collection_select_handler(Param(True))
    

    def update_global_context(self, df_filter, filter_label):
        if df_filter is None and filter_label in self.filters:
            self.filters[filter_label] = None

        self.filters[filter_label] = df_filter
        filters = filter(lambda x: x is not None, self.filters.values())
        df_filter = reduce(lambda x, y: x & y, filters)

        self.df_widget.value = self.df[df_filter]
        self.df_widget.param.trigger('value')
        
        self.update_grid_box_state()
        
    def update_grid_box_state(self, event=None):
        if not event:
            page = self.df_widget.current_view\
                .head(9)\
                .imagesrc\
                .tolist()
        elif type(event) == param.parameterized.Event and event.name == 'page':
            page_size = self.df_widget.page_size
            idx_init = (event.new-1) * page_size
            idx_end = idx_init + page_size
            page = self.df_widget.current_view\
                .iloc[idx_init:idx_end]\
                .imagesrc\
                .tolist()
        else:
            idx = event.row
            img = self.df_widget.current_view.iloc[idx].imagesrc
            page = [img]
        
        base_url = "https://ringsdb.com"
        imgs = [pn.pane.PNG(base_url+i) for i in page]
        self.box.objects = imgs

    def name_search_handler(self, event):
        if event.new:
            df_filter = self.df.name.str.contains(event.new, case=False)
            if event.new == '':
                df_filter = None
            self.update_global_context(df_filter, 'search')

    def sphere_selection_handler(self, event):
        if event.new == 'all':
            self.update_global_context(None, 'sphere')
        else:
            self.update_global_context(self.df.sphere == event.new, 'sphere')

    def collection_select_handler(self, event):
        if event.new:
            self.update_global_context(self.df.quantity_in_collection > 0, 'collection')
        else:
            self.update_global_context(None, 'collection')