from __future__ import annotations

import json
import sys
from collections.abc import Iterable
from pathlib import Path
from typing import Any


EVAL_DIR = Path(__file__).resolve().parent
MULTIVAR_DIR = EVAL_DIR.parent
REPO_ROOT = MULTIVAR_DIR.parent
SRC_DIR = MULTIVAR_DIR / "src"
INFER_DIR = MULTIVAR_DIR / "infer"
DEFAULT_DATA_DIR = MULTIVAR_DIR / "train" / "data_multivar" / "multivar"


def ensure_src_path() -> None:
    src = str(SRC_DIR)
    if src not in sys.path:
        sys.path.insert(0, src)


def ensure_infer_path(path: str | Path | None = None) -> None:
    infer = str(Path(path) if path is not None else INFER_DIR)
    if infer not in sys.path:
        sys.path.insert(0, infer)


def read_jsonl(path: str | Path) -> list[dict[str, Any]]:
    rows: list[dict[str, Any]] = []
    with Path(path).open("r", encoding="utf-8") as handle:
        for line_number, raw_line in enumerate(handle, start=1):
            line = raw_line.strip()
            if not line:
                continue
            try:
                row = json.loads(line)
            except json.JSONDecodeError as exc:
                raise ValueError(f"Invalid JSON on line {line_number} of {path}.") from exc
            if not isinstance(row, dict):
                raise ValueError(f"Expected JSON object on line {line_number} of {path}.")
            rows.append(row)
    return rows


def write_jsonl(path: str | Path, rows: Iterable[dict[str, Any]]) -> None:
    output_path = Path(path)
    output_path.parent.mkdir(parents=True, exist_ok=True)
    with output_path.open("w", encoding="utf-8") as handle:
        for row in rows:
            handle.write(json.dumps(row, ensure_ascii=False, default=json_default) + "\n")


def append_jsonl(path: str | Path, row: dict[str, Any]) -> None:
    output_path = Path(path)
    output_path.parent.mkdir(parents=True, exist_ok=True)
    with output_path.open("a", encoding="utf-8") as handle:
        handle.write(json.dumps(row, ensure_ascii=False, default=json_default) + "\n")


def write_json(path: str | Path, payload: dict[str, Any]) -> None:
    output_path = Path(path)
    output_path.parent.mkdir(parents=True, exist_ok=True)
    output_path.write_text(
        json.dumps(payload, ensure_ascii=False, indent=2, default=json_default),
        encoding="utf-8",
    )


def json_default(obj: Any) -> Any:
    if hasattr(obj, "item"):
        return obj.item()
    if hasattr(obj, "tolist"):
        return obj.tolist()
    if isinstance(obj, Path):
        return str(obj)
    raise TypeError(f"Object of type {type(obj).__name__} is not JSON serializable.")


def parse_csv_arg(raw: str | None) -> list[str] | None:
    if raw is None:
        return None
    values = [item.strip() for item in raw.split(",") if item.strip()]
    return values or None