from __future__ import annotations

import csv
import json
from pathlib import Path
from typing import Iterable


def ensure_parent(path: Path) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)


def write_json(path: Path, data: object) -> None:
    ensure_parent(path)
    with path.open("w", encoding="utf-8") as handle:
        json.dump(data, handle, ensure_ascii=False, indent=2, sort_keys=True)
        handle.write("\n")


def write_jsonl(path: Path, rows: Iterable[dict]) -> int:
    ensure_parent(path)
    count = 0
    with path.open("w", encoding="utf-8") as handle:
        for row in rows:
            handle.write(json.dumps(row, ensure_ascii=False, sort_keys=True))
            handle.write("\n")
            count += 1
    return count


def read_jsonl(path: Path) -> list[dict]:
    rows: list[dict] = []
    with path.open(encoding="utf-8") as handle:
        for line in handle:
            line = line.strip()
            if line:
                rows.append(json.loads(line))
    return rows


def write_csv(path: Path, rows: Iterable[dict], fieldnames: list[str] | None = None) -> int:
    row_list = list(rows)
    if fieldnames is None:
        fieldnames = []
        seen = set()
        for row in row_list:
            for key in row:
                if key not in seen:
                    fieldnames.append(key)
                    seen.add(key)
    ensure_parent(path)
    with path.open("w", newline="", encoding="utf-8") as handle:
        writer = csv.DictWriter(handle, fieldnames=fieldnames)
        writer.writeheader()
        for row in row_list:
            writer.writerow({key: row.get(key, "") for key in fieldnames})
    return len(row_list)


def read_csv_dicts(path: Path) -> list[dict[str, str]]:
    with path.open(newline="", encoding="utf-8") as handle:
        return list(csv.DictReader(handle))