import yaml
import requests
import os
import pandas as pd

from datetime import datetime, timedelta
from dotenv import load_dotenv
load_dotenv()


class IDSC_API():
    '''
    Wrapper class for all IDSC apis
    '''

    def __init__(self):
        __location__ = os.path.realpath(
            os.path.join(os.getcwd(), os.path.dirname(__file__)))

        self.config_path = os.path.join(__location__, 'idsc_config.yaml')
        self.logged_in = False
        self.timeformat = '%m/%d/%Y, %H:%M:%S'
        with open(self.config_path, 'r') as file:
            self.config = yaml.safe_load(file)
            
        self.expire = self.config['apikey_expire']
        self.apikey = self.config['apikey']
        
        self.login()

        self.product_mix__res = None  # Save product_mix api response

    def login(self):
        
        now = datetime.now()
        expire_date = datetime.strptime(self.expire, self.timeformat)

        if now >= expire_date:
            print('apikey expired, requesting new one.')
            self.apikey = self.fetch_apikey()
            self.update_config()
        else:
            print('apikey still available, logged in')
            
        self.logged_in = True

    def fetch_apikey(self):
        # print(os.environ)
        json = {
            # "email": self.config['email'],
            # "pwd": self.config['password']
            'email': os.getenv('IDSC_ACC'),
            'pwd': os.getenv('IDSC_PASS')
        }

        print('IDSC Logging in ...')
        login_resp = requests.post(
            'https://idsc.com.sg/user/login',
            json=json)

        if login_resp.status_code == 200:
            apikey = login_resp.json()["API_key"]
            return apikey
        else:
            raise Exception(login_resp.json())

    def update_config(self):
        now = datetime.now()
        expire = (now + timedelta(days=3)).strftime(self.timeformat)
        self.config['apikey'] = self.apikey
        self.config['apikey_expire'] = expire
        with open(self.config_path, 'w') as f:
            yaml.dump(self.config, f, default_flow_style=False)

    # =========== #
    # Product mix #
    # =========== #

    def product_mix(
            self,
            product_data,
            storage_capacity,
            budget_constraint):

        endpint = 'https://idsc.com.sg/optimax/product-mix/product-mix'
        json = {'product_data': product_data,
                'storage_capacity': storage_capacity,
                'budget_constraint': budget_constraint
                }

        print('storage_capacity', storage_capacity)
        print('budget_constraint', budget_constraint)
        
        self.login()

        headers = {'api-key': self.apikey}

        res = requests.post(endpint, json=json, headers=headers)

        parsed_res = self._parse_response(res)

        self.product_mix__res = parsed_res

        return self.product_mix__res

    def _parse_response(self, res):
        if res.status_code != 200:
            print(f'API call failed. {res.text}')
            return False
        return res.json()

    def get_product_mix_recommendations_df(self):

        try:
            recommendations = self.product_mix__res['product_mix_recommendations']
        except Exception:
            return None

        df_arr = []
        for k, v in recommendations.items():
            df = pd.DataFrame(v, index=[k])
            df['SKU'] = k

            # Make sure expected sales is always integer
            df['expected_sales'] = int(df['expected_sales'])

            # Rearrange the order, so 'SKU' columns is the first
            cols = df.columns.tolist()
            cols = cols[-1:] + cols[:-1]
            df = df[cols]

            df_arr.append(df)

        return pd.concat(df_arr, ignore_index=True)