from __future__ import annotations

import json
from dataclasses import dataclass
from pathlib import Path
from typing import Iterable, List


@dataclass
class SummarizationExample:
    article: str
    summary: str


def load_jsonl(path: str | Path) -> List[SummarizationExample]:
    path = Path(path)
    items: List[SummarizationExample] = []
    with path.open("r", encoding="utf-8") as f:
        for line in f:
            line = line.strip()
            if not line:
                continue
            obj = json.loads(line)
            article = obj.get("article") or obj.get("text") or ""
            summary = obj.get("summary") or obj.get("label") or ""
            if article and summary:
                items.append(SummarizationExample(article=article, summary=summary))
    return items


def iter_pairs(examples: Iterable[SummarizationExample]):
    for ex in examples:
        yield ex.article, ex.summary