from datetime import datetime

import gradio as gr
import gspread
import validators
from validators import ValidationFailure
from google.oauth2.service_account import Credentials
from pydrive.auth import GoogleAuth
from pydrive.drive import GoogleDrive 

import etl

# test sheet - https://docs.google.com/spreadsheets/d/1iJ0-882HsWkAth0e0P_kf21aL6583Z7m1LwloaRCVEc/edit#gid=0
week_list = [f"week_{i}" for i in range(1, 51)]

# credentials file 
cred_file_path = 'heliumhealth-a05d595e5991.json'

# google auth scopes
scopes = ['https://www.googleapis.com/auth/spreadsheets',
          'https://www.googleapis.com/auth/drive']

# create credentials 
credentials = Credentials.from_service_account_file(
    cred_file_path, scopes=scopes )

# authorize google spreadsheet
gc = gspread.authorize(credentials)

gauth = GoogleAuth()
drive = GoogleDrive(gauth)

def overlap_matching(row, d_type):
  """
  matching overlap 
  """
  match_cols = {
      "prescription": ['RX Norm [Super Generic]_x', 'RX Norm [Super Generic]_y'],
      "diagnosis": ['ICD10 Diagnosis_x','ICD10 Diagnosis_y']
  }
  cols = match_cols[d_type]
  row['match_status'] = 'match' if row[cols[0]] == row[cols[1]] else 'no match'
  return row

def overlap_check(gs, start_date, end_date, week_no, d_type):
    """
   load, preprocess, check overlap, postprocess and output data to google sheet 

    Args:
        gs (GSheet instance): Gsheet instance access to google sheet 
        start_date (str): Date str format(YYYY-mm-dd)
        end_date (_type_): Date str format(YYYY-mm-dd)
        d_type (_type_):  sheet type (prescription or diagnosis)
    """
    # load data
    all_data = etl.load_data(gs, start_date, end_date, d_type)

    # preprocess and return overlap data
    overlap_data = etl.preprocess_data(all_data, d_type)

    # do overlap matching 
    overlap_data = overlap_data.apply(overlap_matching, axis=1, args=[d_type])

    # post process 
    overlap_data = etl.post_process(overlap_data, d_type)

    # write to sheet 
    etl.output_data(gc, overlap_data, week_no, d_type)


def overlap_check_main(sheet_type, start_date_str, end_date_str, week_str, sheet_url):
    """
    overlap check main function

    Args:
        sheet_type (str): sheet type (prescription or diagnosis)
        start_date_str (str): start date string: e.g. 2023-03-21 
        end_date_str (str): end date string: e.g. 2023-03-24
        week_str (str): week string e.g. week_1
        sheet_url (url): _description_

    Raises:
        gr.exceptions.Error: Date Format Error - either start_date or end date are bad format
        gr.exceptions.Error: Date Error - when start_date is greater than end date
        gr.exceptions.Error: URL Error - Bad url format
    """
    # format date from string
    try: 
        start_date = datetime.strptime(start_date_str.strip(), "%Y-%m-%d").date()
        end_date = datetime.strptime(end_date_str.strip(), "%Y-%m-%d").date()
    except:
        raise gr.Error(message="Wrong date format")

    # raise error when start date is greater end date
    if start_date >= end_date:
        raise gr.Error(message="Start date cannot be greater end date")
    
    # Check if the input is valid url
    # ToDO: Error message displayed is not explanatory - Fix it 
    url_check = validators.url(sheet_url)
    if isinstance(url_check, ValidationFailure):
        raise gr.Error(message="Please enter a valid URL")
    
    
    # open the google sheet for reading 
    
    gs = gc.open_by_url(sheet_url)
    

    # if sheet_type == 'prescription':
    try:
        overlap_check(gs, start_date_str, end_date_str, week_str,  sheet_type)
    except:
        gr.Error(message="Permission denied. Please add IAM user to the sheet and try again")


    return f"Successfully ran {sheet_type} overlap check for {week_str.replace('_', ' ').title()} ({start_date_str} - {end_date_str})"

with gr.Blocks() as demo:
  gr.Markdown(
      """
      ## Overlap Check App

      * Add IAM User to sheet you want to test
      * Gsheet tabs required for diagnosis:  
        * Diagnosis
      * Gsheet tabs required for prescription:  
        * Prescriptions
      * Data headers required for diagnosis
        * Unstructured Name, ICD10 Diagnosis, Intern
      * Data headers required for prescription
        * Unstructured Name, RX Norm [Super Generic], Intern 
      """
  )
  # inputs
  sheet_type = gr.Dropdown(['prescription', 'diagnosis'], label="QA Type")
  start_date = gr.Textbox(label="Start Date", placeholder="YYYY-MM-DD")
  end_date = gr.Textbox(label="End Date", placeholder="YYYY-MM-DD")
  week_input = gr.Dropdown(week_list, label="Week")
  url = gr.Textbox(label="URL", placeholder="Enter sheet url ...")
  
  # outputs
  output = gr.Textbox(label="Output Box")
  
  run_btn = gr.Button("Run")
  run_btn.click(
      fn=overlap_check_main,
      inputs=[
          sheet_type,
          start_date,
          end_date, 
          week_input, 
          url
          ],
      outputs=output, 
      api_name="Overlap_check"
  )

demo.launch()