from __future__ import annotations

from typing import Iterable

from .csv_parsers import get_parser
from .models import Expense


class CSVImportResult:
    def __init__(self, imported: int, duplicated: int) -> None:
        self.imported = imported
        self.duplicated = duplicated


def import_csv_lines(lines: Iterable[str]) -> CSVImportResult:
    buffered_lines = list(lines)
    parser = get_parser(buffered_lines)
    rows = parser.parse(buffered_lines)
    imported = 0
    duplicated = 0
    for row in rows:
        expense, created = Expense.objects.get_or_create(
            source=row.source,
            source_hash=row.source_hash,
            defaults={
                'use_date': row.use_date,
                'description': row.description,
                'amount': row.amount,
                'note': row.note,
            },
        )
        if created:
            imported += 1
        else:
            duplicated += 1
    return CSVImportResult(imported=imported, duplicated=duplicated)