"""# Automatic Crypto Seller.

Automatic one-way trades.

This is a wrapper about [`fin_depo`](https://gitfub.space/Jmaa/fin-depo/) for
automatically trading one way trades, by using repeated trades
over a period.

The primary motivation is for trading low-volume crypto assets slowly without
affecting the price too much.

Supported sites:

- [KuCoin](https://www.kucoin.com/): Online crypto-currency exchange.

## Installation

Install dependencies:

```shell
pip install -r requirements.txt
```

## Usage

Run using from the top directory:

```shell
python -m crypto_seller
```

The script will now automatically sell assets over time. The interval between
sell-offs are randomized to avoid front-running, and the amounts are also
randomized to avoid too consistent behaviour.

The log will both be displayed in the shell, and be placed in a log file
`output/log.txt`. Every sell-off will be logged to the `output/trades.csv`
file, with as much information as possible. Keep both of these for tax
purposes, if relevant.

## Auditing information

The most relevant libraries for auditing are:

- [`fin_depo`](https://gitfub.space/Jmaa/fin-depo): Library for programmatic
  fetching of depository assets and in some cases allows for order placement.
  This is the library that reads balances and places market orders.
- [`fin_defs`](https://gitfub.space/Jmaa/fin-defs): Definitions of financial
  assets and instruments. Used by `fin_depo`.
- [`python-kucoin`](https://python-kucoin.readthedocs.io/en/latest/) is used by
  `fin_depo` for providing KuCoin support.

## Taxation

Some parts of the world suffers from weird and draconian taxation rules on
cryptocurrencies, so it helps to keep track of the relevant trading
information.

As mentioned above, keep (and backup) both the log file (`output/log.txt`) and
the trades file (`output/trades.csv`).

To help with tax reporting, it might be useful to sign up to tax oriented
websites. For example, [CryptoSkat](https://cryptoskat.dk/) seems to be the
most mature on the danish market, and does support KuCoin.

## TODO

- [ ] Parse configuration from json.
- [ ] Ensure that a failure during selling results in a safe winding down of the system.
      * Catch runtime errors when selling
      * Show errors to log.
      * Stop loop and exit with results, and error indicator.
- [ ] Document configuration
- [ ] Document code auditing
- [X] Ensure sell time is included in order details
- [X] Log all trades to CSV file.
- [X] Collect information during the run and output after run

"""

__all__ = ['__version__', 'run_auto_sell']

import dataclasses
import datetime
import logging
import random
from collections.abc import Callable
from decimal import Decimal
from pathlib import Path
from typing import Any

import fin_defs
import fin_depo

from ._version import __version__

logger = logging.getLogger(__name__)

################################################################################
# Main code #

@dataclasses.dataclass(frozen=True)
class AutoSellConfig:
    """Configuration for `run_auto_sell`.

    Fields:

    - `interval_range`: The range to determine sell-off intervals from. After
      each sell-off it will sleep an amount of time uniformly sampled from this
      range.
    - `input_asset`: Asset to sell.
    - `input_amount_range`: Range to uniformly sample sell-off sizes from.
    - `output_asset`: Asset to "buy".
    - `seller`: Depository seller to use.
    - `sleep`: Sleep method to use.
    - `exit_when_empty`: Whether the system should stop once there is nothing
      more to sell. Recommended.
    """

    interval_range: tuple[datetime.timedelta, datetime.timedelta]
    input_asset: fin_defs.Asset
    input_amount_range: tuple[Decimal, Decimal]
    output_asset: fin_defs.Asset
    seller: fin_depo.defi_kucoin.KucoinDepoFetcher
    sleep: Callable[[float], None]
    log_order_to_csv: Callable[[fin_depo.data.TradeOrderDetails], None]
    exit_when_empty: bool = True


@dataclasses.dataclass(frozen=True)
class AutoSellRunResults:
    """Result information after `run_auto_sell`.

    Fields:
    - `order_details`: The list of order details.
    - `total_duration`: Total duration of the run.
    - `total_sleep_duration`: Amount of time spent waiting between sell-offs.
    """

    order_details: list[fin_depo.data.TradeOrderDetails]
    total_duration: datetime.timedelta
    total_sleep_duration: datetime.timedelta

    def total_input_amount(self) -> Decimal:
        """Total amount of assets sold."""
        return sum(o.input_amount for o in self.order_details)

    def total_output_amount(self) -> Decimal:
        """Total amount of assets "bought"."""
        return sum(o.output_amount for o in self.order_details)


def sample_from_range(rng: random.Random, range: tuple[Any, Any]) -> Any:
    """Samples uniformly from the given range."""
    multiplier: float | Decimal = rng.random()
    if isinstance(range[0], Decimal):
        multiplier = Decimal(multiplier)
    return range[0] + (range[1] - range[0]) * multiplier


def run_auto_sell(config: AutoSellConfig) -> AutoSellRunResults:
    """Executes the sell-off.

    Sell-offs are performed in rounds of sizes and with intervals randomly
    based on the given configuration.
    """
    rng = random.SystemRandom()

    time_start = datetime.datetime.now(tz=datetime.UTC)
    all_executed_orders: list[fin_depo.data.TradeOrderDetails] = []
    total_sleep_duration = datetime.timedelta(seconds=0)

    while True:
        # Check that account has tokens.
        input_amount_available = config.seller.get_depo().get_amount_of_asset(
            config.input_asset,
        )
        logger.info('Currently own %s %s', input_amount_available, config.input_asset)

        if input_amount_available > 0:
            amount_to_sell = sample_from_range(rng, config.input_amount_range)
            amount_to_sell = min(input_amount_available, amount_to_sell)
            logger.info('Attempting to sell %s %s', amount_to_sell, config.input_asset)

            order_details = config.seller.place_market_order(
                config.input_asset,
                amount_to_sell,
                config.output_asset,
            )

            config.log_order_to_csv(order_details)
            all_executed_orders.append(order_details)

            del amount_to_sell
        elif config.exit_when_empty:
            break

        # Time out
        time_to_sleep = sample_from_range(rng, config.interval_range)
        time_to_sleep_secs = time_to_sleep.total_seconds()
        logger.info('Sleeping %s (%d seconds)', time_to_sleep, time_to_sleep_secs)
        config.sleep(time_to_sleep_secs)
        total_sleep_duration += time_to_sleep

        del input_amount_available

    time_end = datetime.datetime.now(tz=datetime.UTC)

    return AutoSellRunResults(
        all_executed_orders,
        total_duration=time_end - time_start,
        total_sleep_duration=total_sleep_duration,
    )


def log_results(results: AutoSellRunResults):
    logger.info('Stats:')
    logger.info('- Num orders:     %s', len(results.order_details))
    logger.info('- Total sold:     %s', results.total_input_amount())
    logger.info('- Total gained:   %s', results.total_output_amount())
    logger.info(
        '- Total duration: %s (%s spent sleeping)',
        results.total_duration,
        results.total_sleep_duration,
    )