import csv
from io import StringIO
from .model import Issue, Sample


def parse_csv(text: str) -> tuple[list[Sample], list[Issue]]:
    samples, issues = [], []
    reader = csv.DictReader(StringIO(text))
    required = {"time_ms", "temperature_c", "voltage_v"}
    if not reader.fieldnames or not required.issubset(reader.fieldnames):
        return [], [Issue(1, "HEADER", "缺少必需列")]
    for line, row in enumerate(reader, 2):
        try:
            samples.append(Sample(line, int(row["time_ms"]), float(row["temperature_c"]), float(row["voltage_v"])))
        except (TypeError, ValueError):
            issues.append(Issue(line, "PARSE", "数值缺失或格式错误"))
    return samples, issues