import xml.etree.ElementTree as ET
from datetime import timedelta
from typing import Callable, List, Optional, Tuple

from fastapi import HTTPException, UploadFile

from models import PodcastEpisode


async def djuced_track_list(
    episode: PodcastEpisode, file: UploadFile
) -> Optional[PodcastEpisode]:
    root = ET.fromstring(await file.read())

    # if this doesn't look like a djuced track list xml, return nothing
    if root.tag != "recordEvents":
        return None

    tracks = []

    for track in root.iter("track"):
        title = track.get("song")
        artist = track.get("artist")

        intervals = track.findall("interval")

        # if the title looks like it contains the artist too, overwrite the existing artist
        title_segments = title.split(" - ")
        if len(title_segments) == 2:
            artist, title = title_segments

        for interval in intervals:
            tracks.append((float(interval.get("start")), title, artist))

    # sort by start time
    tracks = sorted(tracks, key=lambda x: x[0], reverse=False)

    # update description
    track_list_str = ""

    for i, (t, title, artist) in enumerate(tracks):
        time = timedelta(seconds=round(t))
        track_list_str += f"{i + 1}. {title} _- {artist} [{time}]_\n"

    episode.description += "\n\n**Track list**\n\n" + track_list_str
    return episode


# list of file processors
# these are processed in order and only run if the file content type matches the first tuple string
# the second tuple item is the function to run which should return none if the file was not able to be processed, otherwise a mutated episode object
processors: List[
    Tuple[str, Callable[[PodcastEpisode, UploadFile], Optional[PodcastEpisode]]]
] = [("text/xml", djuced_track_list)]


async def process_additional_episode_upload(
    episode: PodcastEpisode, file: UploadFile
) -> PodcastEpisode:
    for processor_content_type, do_process in processors:
        if processor_content_type != file.content_type:
            continue

        try:
            result = await do_process(episode, file)

            if result is not None:
                return result
        except Exception as e:
            print(f"Failed to process using {do_process.__name__}: {e}")
            continue

    raise HTTPException(
        status_code=400,
        detail=f"Unable to process additional episode upload ({file.content_type})",
    )