KomeijiForce/BanG_Dream_Events

from copy import deepcopy
from datasets import load_dataset


def load_ar_pairs(character, lang="en", context_window=10):
    ds = load_dataset(
        "KomeijiForce/BanG_Dream_Events",
        lang,
        split="train",
    )

    pairs = []
    action_seq = []
    last_key = None

    for item in ds:
        item = dict(item)
        key = (item["event_id"], item["chapter"])

        if last_key is not None and key != last_key:
            action_seq = []

        speaker = item.get("windowDisplayName") or item.get("speaker") or ""
        characters = [x.strip() for x in speaker.split("&") if x.strip()]

        item["characters"] = characters
        item["action"] = item.get("text", "")

        if character in characters:
            scene = "\n".join(x["action"] for x in action_seq[-context_window:])
            pairs.append({
                **item,
                "scene": scene,
                "action_seq": deepcopy(action_seq),
            })

        action_seq.append(item)
        last_key = key

    return pairs