#!/usr/bin/python3
"""
Module for Polar articles and highlights
"""


from pathlib import Path
from datetime import datetime
import logging
from typing import List, Dict, Iterator, NamedTuple, Sequence, Optional
import json

import pytz
# TODO declare DEPENDS = [pytz??]

from ..common import setup_logger

from ..error import ResT, echain, unwrap, sort_res_by
from ..kython.konsume import wrap, zoom, ignore


# TOFO FIXME appdirs??
_POLAR_DIR = Path('~/.polar')


# TODO FIXME lazylogger??
def get_logger():
    # TODO __package__?
    return logging.getLogger('my.reading.polar')


def _get_datas() -> List[Path]:
    return list(sorted(_POLAR_DIR.expanduser().glob('*/state.json')))


def parse_dt(s: str) -> datetime:
    return pytz.utc.localize(datetime.strptime(s, '%Y-%m-%dT%H:%M:%S.%fZ'))

Uid = str

# TODO get rid of this?
class Error(Exception):
    def __init__(self, p: Path, *args, **kwargs) -> None:
        super().__init__(*args, **kwargs) # type: ignore
        self.uid: Uid = p.parent.name

# Ok I guess handling comment-level errors is a bit too much..
Cid = str
class Comment(NamedTuple):
    cid: Cid
    created: datetime
    text: str

Hid = str
class Highlight(NamedTuple):
    hid: Hid
    created: datetime
    selection: str
    comments: Sequence[Comment]


Result = ResT['Book', Error]

class Book(NamedTuple):
    uid: Uid
    created: datetime
    filename: str
    title: Optional[str]
    items: Sequence[Highlight]


class Loader:
    def __init__(self, p: Path) -> None:
        self.path = p
        self.uid = self.path.parent.name
        self.err = Error(p)
        self.logger = get_logger()

    def error(self, cause, extra=''):
        return echain(Error(self.path, extra), cause)

    def load_item(self, meta) -> Iterator[Highlight]:
        # TODO this should be destructive zoom?
        meta['notes'].zoom()
        meta['pagemarks'].zoom()
        if 'notes' in meta:
            # TODO something nicer?
            notes = meta['notes'].zoom()
        else:
            notes = [] # TODO FIXME dict?
        comments = meta['comments'].zoom()
        meta['questions'].zoom()
        meta['flashcards'].zoom()
        highlights = meta['textHighlights'].zoom()
        meta['areaHighlights'].zoom()
        meta['screenshots'].zoom()
        meta['thumbnails'].zoom()
        if 'readingProgress' in meta:
            meta['readingProgress'].zoom()

        # TODO want to ignore the whold subtree..
        pi = meta['pageInfo'].zoom()
        pi['num'].zoom()

        # TODO how to make it nicer?
        cmap: Dict[Hid, List[Comment]] = {}
        vals = list(comments.values())
        for v in vals:
            cid = v['id'].zoom()
            v['guid'].zoom()
            # TODO values should probably be checked by flow analysis??
            crt = v['created'].zoom()
            updated = v['lastUpdated'].zoom()
            content = v['content'].zoom()
            html = content['HTML'].zoom()
            refv = v['ref'].zoom().value
            [_, hlid] = refv.split(':')
            ccs = cmap.get(hlid, [])
            cmap[hlid] = ccs
            ccs.append(Comment(
                cid=cid.value,
                created=parse_dt(crt.value),
                text=html.value, # TODO perhaps coonvert from html to text or org?
            ))
            v.consume()
        for h in list(highlights.values()):
            hid = h['id'].zoom().value
            if hid in cmap:
                comments = cmap[hid]
                del cmap[hid]
            else:
                comments = []

            h['guid'].consume()
            crt = h['created'].zoom().value
            updated = h['lastUpdated'].zoom().value
            h['rects'].ignore()

            h['textSelections'].ignore()
            h['notes'].consume()
            h['questions'].consume()
            h['flashcards'].consume()
            h['color'].consume()
            h['images'].ignore()
            # TODO eh, quite excessive \ns...
            text = h['text'].zoom()['TEXT'].zoom().value

            yield Highlight(
                hid=hid,
                created=parse_dt(crt),
                selection=text,
                comments=tuple(comments),
            )
            h.consume()

        if len(cmap) > 0:
            raise RuntimeError(f'Unconsumed comments: {cmap}')
        # TODO sort by date?


    def load_items(self, metas) -> Iterator[Highlight]:
        for p, meta in metas.items():
            with wrap(meta) as meta:
                yield from self.load_item(meta)

    def load(self) -> Iterator[Result]:
        self.logger.info('processing %s', self.path)
        j = json.loads(self.path.read_text())

        # TODO konsume here as well?
        di = j['docInfo']
        added = di['added']
        filename = di['filename']
        title = di.get('title', None)
        tags = di['tags']
        pm = j['pageMetas']

        yield Book(
            uid=self.uid,
            created=parse_dt(added),
            filename=filename,
            title=title,
            items=list(self.load_items(pm)),
        )


def iter_entries() -> Iterator[Result]:
    logger = get_logger()
    for d in _get_datas():
        loader = Loader(d)
        try:
            yield from loader.load()
        except Exception as ee:
            err = loader.error(ee)
            logger.exception(err)
            yield err


def get_entries() -> List[Result]:
    # sorting by first annotation is reasonable I guess???
    # TODO
    return list(sort_res_by(iter_entries(), key=lambda e: e.created))


def main():
    logger = get_logger()
    setup_logger(logger, level=logging.DEBUG)

    for entry in iter_entries():
        logger.info('processed %s', entry.uid)
        try:
            ee = unwrap(entry)
        except Error as e:
            logger.exception(e)
        else:
            for i in ee.items:
                logger.info(i)


if __name__ == '__main__':
    main()