import streamlit as st # for overall GUI
from streamlit_calendar import calendar # to show calendar
from dateutil.relativedelta import relativedelta # for addition to dates
import datetime
import os # for extracting environment variable
from urllib.request import urlopen # for getting data from FMP API
import json # for parsing data from FMP API

# For parsing data from API from JSON to a Python Dictionary
def get_jsonparsed_data(url):
    response = urlopen(url)
    data = response.read().decode("utf-8")
    return json.loads(data)

# Get FMP API stored as environment variable
apiKey = os.environ['FMP_API_KEY']

# Financialmodelingprep (FMP) api base url
base_url = "https://financialmodelingprep.com/api/v3/"


# Get today's date and add 3 months to it
# Convert both today's date and the 3 months later date to strings (for input into API endpoint URL later)
# This is the date range within which we want to get our earnings dates 
today = datetime.datetime.today()
today_string = today.strftime('%Y-%m-%d')
future_string = (today + relativedelta(months=3)).strftime('%Y-%m-%d')

# This is the full API endpoint to get the earnings dates from today to 6 months after
url = f"{base_url}earning_calendar?from={today_string}&to={future_string}&apikey={apiKey}"

# This decorator ensures that the call to the FMP API will only run once at the start of this app
# The data returned will be cached after the function runs
# Without this decorator, the API will be called each time you click something in the streamlit app
@st.cache_resource
def get_earnings_dates(url):
    events = get_jsonparsed_data(url)
    return events
    
events = get_earnings_dates(url)


with st.sidebar:
    st.title("Stock Earnings 📆 App")
    st.header("Choose Tickers of Interest")
    #tickers = ['GOOG', 'META', 'TSLA', 'NET', 'V', 'MA', 'BA', 'C']
    
    # For users to enter tickers of interest
    tickers_string = st.text_area('Enter all stock tickers to be included in calendar, separated by commas \
								e.g. "MA, META, V, AMZN, JPM, BA"', 
                                value = 'GOOG, META, AAPL, MSFT, NVDA, NFLX, V, MA, AMZN, TSLA, JPM, BAC, BA, MMM, NET, C, CRM, PLTR, BABA').upper()
    st.write("Note: Earnings dates are shown for the next 3 months")
    st.write('')

    st.markdown("## [Explanatory Article](https://medium.datadriveninvestor.com/build-a-stock-earnings-calendar-of-your-favorite-stocks-in-python-36bba1950a61)")
    st.write('')

    # Where the data came from
    st.markdown("## [Financial Modeling Prep API](https://intelligence.financialmodelingprep.com/pricing-plans?couponCode=damianboh&utm_campaign=damianboh&utm_medium=blog&utm_source=medium)\
    \n\nEarnings Dates for all tickers are obtained from the FinancialModelingPrep API, feel free to sign up\
    [here](https://intelligence.financialmodelingprep.com/pricing-plans?couponCode=damianboh&utm_campaign=damianboh&utm_medium=blog&utm_source=medium)\
    if you wish.")
   
# Parse user input into a list
tickers_string = tickers_string.replace(' ', '')
tickers = tickers_string.split(',')

# Converts the parsed json from FMP API into a list of events to be passed into streamlit_calendar
calendar_events = []
for event in events:
    if event['symbol'] in tickers:
        calendar_event = {}
        calendar_event['title'] = event['symbol']
        if event['time'] == 'bmo': # before market opens, add sunrise symbol
            calendar_event['title'] = '☀ ' + calendar_event['title']
        elif event['time'] == 'amc': # after market closes, add sunset symbol
            calendar_event['title'] = '🌅 '   + calendar_event['title']     
        calendar_event['start'] = event['date']
        calendar_events.append(calendar_event)

st.header("Stock Earnings Calendar 📆")


calendar_options = {
        "editable": "true",
        "navLinks": "true",
        "headerToolbar": {
            "left": "today prev,next",
            "center": "title",
            "right": "dayGridDay,dayGridWeek,dayGridMonth,listMonth",
        },
        #"initialDate": today.strftime('%Y-%m-%d'),
        "initialView": "dayGridMonth"
    }
    

custom_css="""
    .fc-event-past {
        opacity: 0.8;
    }
    .fc-event-time {
        font-style: italic;
    }
    .fc-event-title {
        font-weight: 700;
    }
    .fc-toolbar-title {
        font-size: 2rem;
    }
"""


calendar = calendar(events=calendar_events, options=calendar_options, custom_css=custom_css)