import logging
from io import TextIOWrapper

try:
    from utilsv2 import utils
    from utilsv2.log import logger
    from utilsv2.nordic import evtype, parse_event, parse_stations_V1, sttype
except ModuleNotFoundError:
    import utils
    from log import logger
    from nordic import evtype, parse_event, parse_stations_V1, sttype

logger = logging.getLogger(__name__)


def read_file(fname: str) -> TextIOWrapper | OSError:
    try:
        fp = open(fname, "r", newline="\n")
        return fp
    except FileNotFoundError:
        return FileNotFoundError("Nenhum ficheiro encontrado")
    except PermissionError:
        return PermissionError("Sem permissões para abrir")


def find_events(fp: TextIOWrapper) -> list[tuple[int, int]]:
    event_indices = []

    event_start = -1
    idx = 0
    for line in fp.read().split("\n"):
        if event_start == -1:
            event_start = idx
        if utils.is_empty(line):
            event_indices.append((event_start, idx))
            event_start = -1
        idx += 1

    logger.info("Found %d events", len(event_indices))
    return event_indices


def split_event(lines: list[str], start: int, end: int) -> int:
    for idx in range(start, end):
        if lines[idx].endswith("7"):
            return idx
    return -1


def extract_event(
    fp: TextIOWrapper, event_bounds: list[tuple[int, int]]
) -> tuple[list[evtype], list[sttype]]:
    lines = fp.read().split("\n")
    events, ev_stations = [], []

    for event_idx in event_bounds:
        stations = split_event(lines, event_idx[0], event_idx[1])
        if stations == -1:
            logger.error(f"Could not parse event at pos {event_idx}")
            continue
        ev = parse_event(lines[event_idx[0] : stations])
        events.append(ev)
        ev_stations.append(
            parse_stations_V1(lines[stations + 1 : event_idx[1]], ev["ID"])
        )

    return events, ev_stations


def parse(fname: str):
    _ret = read_file(fname)
    if not isinstance(_ret, TextIOWrapper):
        logger.critical(_ret.__str__())
        raise _ret

    events = find_events(_ret)
    _ret.seek(0)
    evs, stations = extract_event(_ret, events)

    # cleanup
    _ret.close()

    return evs, stations