"""# Crypto Tax.

Tool to automatically perform tax computations of crypto transactions from the danish perspective.

## TODO

This tool is a work in progress:

- [ ] Support Partisia Blockchain
- [ ] Fix Kucoin issues.
- [ ] Produce Excel output file:
  * Sheet 1: Gives a basic overview, including computed tax values from the rest of
    the sheet, and reasonings for these. Gives an overview of the other sheets.
  * Sheet 2: Current assets, including FIFO acquisition prices.
  * Sheet 3: Historic sales, with FIFO.
"""

import sys
import requests
import fin_depo
from . import secrets
from fin_defs import CryptoCurrency, AssetAmount, MPC, Asset, USDT
from decimal import Decimal
from collections import deque
from fin_depo.data import *
import datetime
import dataclasses
import logging
import fin_data

from .data import TaxReport, BoughtAndSold, BoughtAndNotYetSold

logger = logging.getLogger(__name__)

FIN_DB = fin_data.FinancialDatabase(enable_kucoin=True, enable_nationalbanken_dk=True)


def compute_tax(transfers: list) -> TaxReport:
    transfers.sort(key=lambda t:t.executed_time)


    bought_and_sold_for: list[BoughtAndSold] = []
    bought_and_spent_for: list[BoughtAndSold] = []

    prices_bought_for: dict[Asset, deque[BoughtAndNotYetSold]] = {}
    if False:
        prices_bought_for[MPC] = deque()
        prices_bought_for[MPC].append(BoughtAndNotYetSold(AssetAmount(MPC, Decimal(100)), datetime.datetime(2000, 1,1,1,1,1,1)))
        prices_bought_for[USDT] = deque()
        prices_bought_for[USDT].append(BoughtAndNotYetSold(AssetAmount(USDT, Decimal(100)), datetime.datetime(2000, 1,1,1,1,1,1)))

    def sell(amount: AssetAmount, executed_time: datetime.datetime, spent=False):
        logger.info(f'Selling: {amount}')
        while amount.amount > 0:
            if len(prices_bought_for[amount.asset]) == 0:
                raise Exception('Miscalculation: ' + str(amount))
            partial = prices_bought_for[amount.asset].popleft()

            logger.info(f'Fuck : {amount} - {partial.amount}')

            amount_covered_by_partial = min(partial.amount, amount)
            amount -= amount_covered_by_partial
            new_partial_amount = partial.amount - amount_covered_by_partial

            logger.info(f'  => {amount}  ({new_partial_amount}')

            # Re-add partial
            if new_partial_amount.amount != 0:
                new_partial = BoughtAndNotYetSold(new_partial_amount, partial.time_bought)
                logger.info(f'  => new partial: {new_partial}')
                prices_bought_for[amount.asset].appendleft(new_partial)
                del new_partial

            # Add FIFO like
            if spent:
                bought_and_spent_for.append(BoughtAndSold(amount_covered_by_partial, partial.time_bought, executed_time))
            else:
                bought_and_sold_for.append(BoughtAndSold(amount_covered_by_partial, partial.time_bought, executed_time))

            del partial, amount_covered_by_partial

    def spend(amount: AssetAmount, executed_time: datetime.datetime):
        logger.info(f'Spending: {amount}')
        sell(amount, executed_time, spent=True)

    for transfer in transfers:
        logger.info(transfer)
        # Buy
        if output := transfer.output:
            logger.info('Buy')
            if output.asset not in prices_bought_for:
                prices_bought_for[output.asset] = deque()
            prices_bought_for[output.asset].append(BoughtAndNotYetSold(output, transfer.executed_time))
        del output

        # Sell
        if _input := transfer.input:
            logger.info('Sell')
            sell(_input, transfer.executed_time)
        del _input

        if fee := transfer.fee:
            logger.info('Sell')
            spend(fee, transfer.executed_time)
        del transfer, fee

    def exchange_rate_at_time(a, b, t):
        try:
            sample = FIN_DB.get_exchange_rate_at_time(a, b, t)
            return sample.average
        except Exception:
            logger.exception('Error when fetching exchange rate (%s,%s) at %s', a, b, t)
            return None

    return TaxReport(
            bought_and_sold_for=bought_and_sold_for,
            bought_and_spent_for=bought_and_spent_for,
            current_assets=prices_bought_for,
            exchange_rate_at_time=exchange_rate_at_time,
    )