'''
graphical line diagram of stock cumulative returns
Note: Raw Data is from Yahoo Finance using python yfinance
Author: Gang Luo

Revision history:
2024-01-28.1:   
   Creation of the file
2025-02.23.0027:  fixing an issue (https://github.com/ranaroussi/yfinance/issues/2283)
   which is introduced by yfinance version 0.2.54 (released on Feb 18, 2025 ).
   The  "Adj Close" column is missing from yf.download since  yf.download default changed 
   from auto_adjust=False to auto_adjust=True. When auto_adjust=True,  column Close is actually Adj Close and 
   Adj Close column does not exist any more.  In order to fix the issue, auto_adjust=False is used explicitly in download function,
   to get back the Adj Close column.
   The  "Adj Close" column is also missing from using  ticker = yf.Ticker("AAPL") data = ticker.history(period="1y")

'''
script_version = '(2025-0223-1156)'
# Import the libraries
import gradio as gr
import yfinance as yf
import pandas as pd
import matplotlib 

def stock_return_df(tickers, start, end):
  # Download the historical data
  data = yf.download(tickers, start=start, end=end, auto_adjust=False) # yf.download default changed to auto_adjust=True at yfinance version 0.2.54,
                                                    # when auto_adjust=True,  Close = Adj Close and Adj Close does not exist
  # Calculate the daily and cumulative percentage change
  data_adj_close = data['Adj Close']
  data_adj_close_pct = data_adj_close.pct_change()
  data_adj_close_pct_cum = (data_adj_close_pct + 1).cumprod(axis=0) - 1
  return data_adj_close_pct_cum

def plot_graph(tickers, start, end):
  data_adj_close_pct_cum=stock_return_df(tickers, start, end)
  # Plot a line chart of the salary by name
  #ax = data_adj_close_pct_cum.plot.line(x="Name", y="Salary", rot=0, legend=False, style="-o", markersize=10, color="green")
  ax = data_adj_close_pct_cum.plot()
  ax.set_ylabel("Percentage")
  ax.set_title("Cumulative Returns")
  # Return the plot as a matplotlib figure
  return ax.get_figure()

# Create a gradio.Interface object with the DataFrame component as input and the Matplotlib component as output
interface = gr.Interface(
    fn=plot_graph, # The function to call
    inputs=[gr.Textbox(label="Tickers", value="qqq,spy,vfv.to,xiu.to,xfn.to,ry.to"),
        gr.Textbox(label="Start Date", value="2014-01-01"),
        gr.Textbox(label="End Date", value="2023-12-30")],
    outputs=gr.Plot(label="Output Plot"), # The Matplotlib component as output
    title="Stock cumulative returns - DataFrame Line Plot by Gradio" # The title of the interface
)

# Launch the interface
interface.launch(debug=False)