import os
import io
import time
import json
import flask
import requests

from dotenv import load_dotenv

load_dotenv()

# cache get_finances() for 5 minutes

def get_finances():
    return requests.get(
        url=f'{os.environ["CORE_API_URL"]}/finances',
        headers={
            'Authorization': f'{os.environ["CORE_API_KEY"]}'
        },
        timeout=5
    ).json()

def register(app):
    @app.route('/finances')
    def finances_view():
        try:
            data = get_finances()
        except Exception:
            return flask.Response('Error fetching finances from database. This might be cause the data is still being processed. Sorry.', status=500)

        finances = {
            'last_update': data['timestamp'],
            'donations_total': round(sum([i['amount_usd'] for i in data['donations']])),
            'donations_num': len(data['donations']),
            'donations_avg': round(sum([i['amount_usd'] for i in data['donations']]) / len(data['donations']), 2),
            'donations_max': round(max([i['amount_usd'] for i in data['donations']])),
            'most_used_donation_currency': max(data['donations'], key=lambda x: x['amount_usd'])['currency'],

            'expenses_total': round(sum([i['amount_usd'] for i in data['expenses']])),
            'expenses_wages': round(sum([i['amount_usd'] for i in data['expenses'] if i['type'] == 'wage'])),
            'most_used_expense_currency': max(data['expenses'], key=lambda x: x['amount_usd'])['currency'],
        }

        return flask.render_template('finances.html', finances=finances)

    @app.route('/finances/json')
    def finances_download():
        try:
            data = get_finances()
        except Exception:
            return flask.Response('Error fetching finances from database. This might be cause the data is still being processed. Sorry.', status=500)

        virtual_file = io.StringIO()
        json.dump(data, virtual_file, indent=4)
        name = f'finances-{time.strftime("%Y-%m-%d")}.json'
        virtual_file.seek(0)

        return flask.send_file(
            io.BytesIO(virtual_file.read().encode('utf-8')),
            mimetype='application/json',
            as_attachment=True,
            download_name=name
        )