def get_df(sellers, items, products, orders):
    merged_df = sellers.merge(items, on = 'seller_id')
    df = products.merge(merged_df, on = 'product_id')
    df = df[['seller_state', 'product_category_name', 'order_id']].merge(orders[['order_status', 'order_id', 'order_delivered_customer_date']], on = 'order_id')
    df.rename(columns = {'product_category_name': 'category', 'seller_state': 'state', 'order_status': 'status', 'order_delivered_customer_date' : 'year'}, inplace = True)
    df['date'] = df['date'].apply(lambda x: pd.to_datetime(x).year)
    return df


app = Dash(__name__)

app.layout = html.Div([
    dcc.Graph(id='sellers-graph'),
    dcc.Slider(
        df['year'].min(),
        df['year'].max(),
        step=None,
        value=df['year'].min(),
        marks={str(year): str(year) for year in df['year'].unique()},
        id='year-slider'
    )
    dcc.Checklist(
        df['state'],
         df['state'],
        id = 'state-slider'
    )
])

df = get_df(sellers, items, products, orders)

@app.callback(
    Output('sellers-graph', 'figure'),
    [Input('date-slider', 'value')
     Input('states-dropdown', 'value'),
     Input('statuses-filter', 'value')])

def update_figure(time_gap, state_to_display, statuses_filter):
    df = df.groupby(['state', 'category', 'status']).agg({'order_id' : 'count'}).reset_index()
    df.rename(columns = {'order_id' : 'count'}, inplace = True)
    df = df.loc[df.state == state_to_display & df.statys = statuses_filter & df.time_gap]
    fig = px.bar(table_1, y="customer_state", x="count", color="category",
                 title="Distribution by sales categories", orientation='h', height=300)

    fig.update_layout(transition_duration=500)
    return fig