#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import base64
import datetime
import io

import dash
from dash.dependencies import Input, Output, State
import dash_core_components as dcc
#mport dash_html_components as html
from dash import html
from dash import dash_table
import plotly.express as px

import pandas as pd

dash.register_page(__name__)

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets,
                suppress_callback_exceptions=True)

layout = html.Div([ # this code section taken from Dash docs https://dash.plotly.com/dash-core-components/upload
    dcc.Upload(
        id='upload-data',
        children=html.Div([
            'Drag and Drop or Select files',
            
        ]),
        
        style={
            'width': '100%',
            'height': '60px',
            'lineHeight': '60px',
            'borderWidth': '1px',
            'border-left': '30px', 
            'borderStyle': 'dashed',
            'borderRadius': '5px',
            'textAlign': 'center',
            'margin': '10px'
        },
        # Allow multiple files to be uploaded
        multiple=True
    ),
    html.Div(id='output-div'),
    html.Div(id='output-datatable'),
])

#def menu(app):
def parse_contents(contents, filename, date):
    content_type, content_string = contents.split(',')

    decoded = base64.b64decode(content_string)
    try:
        if 'csv' in filename:
        # Assume that the user uploaded a CSV file
            df = pd.read_csv(
            io.StringIO(decoded.decode('utf-8')))
        elif 'xls' in filename:
        # Assume that the user uploaded an excel file
            df = pd.read_excel(io.BytesIO(decoded))
    except Exception as e:
        print(e)
        return html.Div([
        'There was an error processing this file.'
    ])

    return html.Div([
    html.H5(filename),
    html.H6(datetime.datetime.fromtimestamp(date)),
    html.P("Inset X axis data"),
    dcc.Dropdown(id='xaxis-data',
                    options=[{'label':x, 'value':x} for x in df.columns]),
    html.P("Inset Y axis data"),
    dcc.Dropdown(id='yaxis-data',
                    options=[{'label':x, 'value':x} for x in df.columns]),
    html.Button(id="submit-button", children="Create Graph"),
    html.Hr(),
    dash_table.DataTable(
        data=df.to_dict('records'),
        columns=[{'name': i, 'id': i} for i in df.columns],
        page_size=15
    ),
    dcc.Store(id='stored-data', data=df.to_dict('records')),
    html.Hr(),  # horizontal line
    # For debugging, display the raw contents provided by the web browser
    html.Div('Raw Content'),
    html.Pre(contents[0:200] + '...', style={
        'whiteSpace': 'pre-wrap',
        'wordBreak': 'break-all'
    })
])


@app.callback(Output('output-datatable', 'children'),
            Input('upload-data', 'contents'),
            State('upload-data', 'filename'),
            State('upload-data', 'last_modified'))
def update_output(list_of_contents, list_of_names, list_of_dates):
    if list_of_contents is not None:
        children = [
        parse_contents(c, n, d) for c, n, d in
        zip(list_of_contents, list_of_names, list_of_dates)]
        return children


@app.callback(Output('output-div', 'children'),
            Input('submit-button','n_clicks'),
            State('stored-data','data'),
            State('xaxis-data','value'),
            State('yaxis-data', 'value'))

def make_graphs(n, data, x_data, y_data):
    if n is None:
        return dash.no_update
    else:
        bar_fig = px.bar(data, x=x_data, y=y_data)
    # print(data)
        return dcc.Graph(figure=bar_fig)