import logging
import asyncio
import json
from argparse import ArgumentParser
from pathlib import Path

from .functions import get_all_financials
from .constants import MAIN_LOGGER_NAME, DEFAULT_CONCURRENT_BATCH_SIZE


log = logging.getLogger(MAIN_LOGGER_NAME)

TICKER_SYMBOL = 'ticker_symbol'
QUARTERLY = 'quarterly'
BATCH_SIZE = 'concurrent_batch_size'
TO_FILE = 'to_file'
JSON_INDENT = 'json_indent'
VERBOSE = 'verbose'


def parse_cli() -> dict:
    """Returns the parsed command line arguments for the program as a dictionary."""
    parser = ArgumentParser(description="Scrape company financials")
    parser.add_argument(
        TICKER_SYMBOL,
        type=str,
        nargs='+',
        help="Stock ticker symbol of the company to be scraped the financials of"
    )
    parser.add_argument(
        '-Q', f'--{QUARTERLY}',
        action='store_true',
        help="If set, the financial data for the last quarters is returned; otherwise yearly data is returned."
    )
    parser.add_argument(
        '-b', f'--{BATCH_SIZE.replace("_", "-")}',
        type=int,
        default=DEFAULT_CONCURRENT_BATCH_SIZE,
        help="If multiple ticker symbols are passed, the company financials can be scraped concurrently. "
             "This argument determines how many companies are scraped concurrently. "
             "By default, they are scraped sequentially (i.e. a batch size of 1)."
    )
    parser.add_argument(
        '-f', f'--{TO_FILE.replace("_", "-")}',
        type=Path,
        help="Writes results to the specified destination file. If omitted results are printed to stdout."
    )
    parser.add_argument(
        f'--{JSON_INDENT.replace("_", "-")}',
        type=int,
        help="If set to a positive integer and the output format is JSON (default), the resulting JSON document is "
             "indented accordingly for more readability; if omitted, output is returned in one line."
    )
    parser.add_argument(
        '-v', f'--{VERBOSE}',
        action='count',
        default=0,
        help="Verbose mode. Reduces the log level and thus prints out more status messages while running. "
             "Using this flag multiple times increases verbosity further."
    )
    return vars(parser.parse_args())


def configure_logging(verbosity: int) -> None:
    """
    Sets up logging by adding a stdout-handler and setting the root logger's level according to the specified verbosity.
    A verbosity of 0 (or less) sets the log level to CRITICAL.
    """
    root_logger = logging.getLogger()
    root_logger.addHandler(logging.StreamHandler())
    root_logger.setLevel(logging.CRITICAL)
    if verbosity > 2:
        root_logger.setLevel(logging.DEBUG)
    elif verbosity == 2:
        root_logger.setLevel(logging.INFO)
    elif verbosity == 1:
        root_logger.setLevel(logging.WARNING)


async def main() -> None:
    """Parses CLI arguments, configures logging to stderr, performs the scraping, and prints/saves the data."""
    args = parse_cli()
    configure_logging(args[VERBOSE])
    data = await get_all_financials(*args[TICKER_SYMBOL], quarterly=args[QUARTERLY],
                                    concurrent_batch_size=args[BATCH_SIZE])
    path: Path = args[TO_FILE]
    if path is None:
        print(json.dumps(data, indent=args[JSON_INDENT]))
        return
    with open(path, 'w') as f:
        json.dump(data, f, indent=args[JSON_INDENT])


if __name__ == '__main__':
    asyncio.run(main())