import argparse
import logging
from pathlib import Path
from collections.abc import Iterable

from . import (
    filter_useless_messages,
    format_messages,
    libpurple,
    merge_adjacent_messages,
    synctech_sms,
)
from .data import Message

logger = logging.getLogger(__name__)


def group_messages_by_chat_id(messages: Iterable[Message]) -> dict[str, list[Message]]:
    by_period: dict[str, list[Message]] = {}
    for msg in messages:
        by_period.setdefault(msg.chat_id, []).append(msg)
        del msg
    return by_period

def group_messages_by_period(messages: Iterable[Message]) -> dict[str, list[Message]]:
    by_period: dict[str, list[Message]] = {}
    for msg in messages:
        period_key = f'{msg.sent_at.year}-{msg.sent_at.month:02}'
        by_period.setdefault(period_key, []).append(msg)
        del msg
    return by_period


def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument('--purple', type=Path, dest='purple_folder')
    parser.add_argument('--synctech', type=Path, dest='synctech_sms_backup_file')
    parser.add_argument('--output', type=Path)
    return parser.parse_args()


def main():
    logging.basicConfig()
    logging.getLogger().setLevel('INFO')
    args = parse_args()

    if args.purple_folder:
        all_messages = libpurple.parse_messages_in_chat_folder(args.purple_folder)
    elif args.synctech_sms_backup_file:
        all_messages = synctech_sms.parse_messages_in_backup_xml_file(args.synctech_sms_backup_file)
    else:
        logger.fatal('No input file given!')
        return

    all_messages = list(all_messages)
    logger.info('%d messages after loading', len(all_messages))

    all_messages = list(filter_useless_messages(all_messages))
    logger.info('%d messages after filtering', len(all_messages))

    messages_by_chat_id = group_messages_by_chat_id(all_messages)
    logger.info('%d message groups', len(messages_by_chat_id))
    del all_messages

    for chat_id, messages_in_chat_original in messages_by_chat_id.items():
        messages_in_chat = merge_adjacent_messages(messages_in_chat_original )

        messages_by_period = group_messages_by_period(messages_in_chat)

        for period_key, messages in messages_by_period.items():
            output_file = args.output / f'{chat_id} - {period_key}.md'
            logger.info('Writing % 5d messages to %s', len(messages), output_file)
            with open(output_file, 'w') as f:
                f.write(
                    format_messages(
                        messages,
                        title=f'{chat_id} - {period_key}',
                    ),
                )

            del period_key, messages, output_file
        del chat_id, messages_in_chat_original, messages_in_chat


if __name__ == '__main__':
    main()