"""Libpurple to markdown conversion script.

Conversion script for HTML-based logs from [Pidgin/Libpurple](https://pidgin.im/) chat program.

**This is an one-off script, and is not actively maintained.**

## Motivation

I recently discovered [Obsidian](https://obsidian.md) and liked the prospect of
cross-referencing my notes with my old chat logs. Libpurple uses HTML logs if
you haven't configured it to something else (which I haden't).

I no longer use IRC or Pidgin as my entire friend group have switched to using
Matrix.

## Usage

From the repository root:

```bash
python -m libpurple_to_markdown LOG_DIRECTORY --output OUTPUT_FOLDER
```

It was made specifically for import into Obsidian, so it might not suite your
purposes, but it shouldn't be too difficult to adjust.
"""

import dataclasses
import datetime
import logging
import re
from collections.abc import Iterable, Iterator

from ._version import __version__
from .data import Message

__all__ = ['__version__']

logger = logging.getLogger(__name__)


def datetime_sent(
    chat_start: datetime.datetime,
    message_sent: datetime.time,
) -> datetime.datetime:
    naive = datetime.datetime.combine(
        chat_start.date(),
        message_sent,
        chat_start.tzinfo,
    )
    if chat_start.time() > message_sent:
        naive = naive + datetime.timedelta(days=1)
    return naive


def format_message_as_citation(out: list[str], msg: Message) -> None:
    out.append(f'{msg.sent_at.date()} {msg.sent_at.time()} [[{msg.sender}]]:')
    out.append('\n')
    for line in msg.text.split('\n'):
        line = re.sub(r'(<[\w ]+>)', r'`\1`', line)
        line = re.sub(r'(\$\$\$)', r'`\1`', line)
        out.append(f'> {line}\n')
        del line
    out.append('\n')


def format_message_as_table(out: list[str], msg: Message) -> None:
    out.append(f'| {msg.sent_at} | [[{msg.sender}]] | ')
    for line in msg.text.split('\n'):
        out.append(f'{line}')
        del line
    out.append('|\n')


def format_messages(messages: list[Message], title: str) -> str:
    out = ['# ', title, '\n\n']

    as_table = False

    for msg_idx, msg in enumerate(messages):
        if msg_idx == 0 or messages[msg_idx - 1].sent_at.date() != msg.sent_at.date():
            out.append('---\n')
            out.append(f'## [[{msg.sent_at.date()}]]\n\n')
            if as_table:
                out.append('| sent at | sender | text |\n')
                out.append('| ------- | ------ | ---- |\n')

        if as_table:
            format_message_as_table(out, msg)
        else:
            format_message_as_citation(out, msg)
        del msg

    return ''.join(out)


MSG_ADJACENTCY_DIST = datetime.timedelta(minutes=2)


def is_useless_message(msg: Message) -> bool:
    return msg.sender.endswith('<AUTO-REPLY>') or msg.sender == ''


def filter_useless_messages(messages: Iterable[Message]) -> Iterator[Message]:
    for msg in messages:
        if not is_useless_message(msg):
            yield msg
        else:
            print(msg.text)


def is_adjacent_messages(first: Message, second: Message) -> bool:
    return (
        first.sender == second.sender
        and second.sent_at - first.sent_at <= MSG_ADJACENTCY_DIST
    )


def merge_texts(text1: str, text2: str) -> str:
    punctuated = text1.endswith('.?!,:')
    # return text1 + (' ' if punctuated else '. ') + text2
    return text1 + (' ' if punctuated else '. ') + '\n' + text2


def merge_adjacent_messages(messages: Iterable[Message]) -> list[Message]:
    out: list[Message] = []
    for msg in messages:
        if out and is_adjacent_messages(out[-1], msg):
            out[-1] = dataclasses.replace(
                out[-1],
                text=merge_texts(out[-1].text, msg.text),
            )
        else:
            out.append(msg)
    return out