from __future__ import annotations

import json
from datetime import datetime, timezone
from pathlib import Path
from typing import Any


def ensure_utc(value: datetime) -> datetime:
    if value.tzinfo is None:
        return value.replace(tzinfo=timezone.utc)
    return value.astimezone(timezone.utc)


def utc_now() -> datetime:
    return datetime.now(timezone.utc)


def parse_datetime(value: Any) -> datetime | None:
    if value in (None, ""):
        return None
    if isinstance(value, datetime):
        return ensure_utc(value)
    text = str(value).strip()
    candidates = [
        text,
        text.replace("Z", "+00:00"),
        text.replace(" ", "T"),
        text.replace(" ", "T").replace("Z", "+00:00"),
    ]
    for candidate in candidates:
        try:
            return ensure_utc(datetime.fromisoformat(candidate))
        except ValueError:
            continue
    for fmt in ("%Y-%m-%d %H:%M:%S", "%Y-%m-%d"):
        try:
            parsed = datetime.strptime(text, fmt)
            return parsed.replace(tzinfo=timezone.utc)
        except ValueError:
            continue
    return None


def isoformat_z(value: datetime) -> str:
    return ensure_utc(value).isoformat().replace("+00:00", "Z")


def format_modelhub_datetime(value: datetime) -> str:
    return ensure_utc(value).strftime("%Y-%m-%d %H:%M:%S")


def json_dumps(value: Any) -> str:
    return json.dumps(value, ensure_ascii=False, sort_keys=True)


def read_json(path: Path) -> Any:
    return json.loads(path.read_text(encoding="utf-8"))


def write_json(path: Path, value: Any) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(json.dumps(value, ensure_ascii=False, indent=2, sort_keys=True) + "\n", encoding="utf-8")


def read_jsonl(path: Path) -> list[dict[str, Any]]:
    if not path.exists():
        return []
    rows: list[dict[str, Any]] = []
    for line in path.read_text(encoding="utf-8").splitlines():
        if not line.strip():
            continue
        rows.append(json.loads(line))
    return rows


def write_jsonl(path: Path, rows: list[dict[str, Any]]) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    content = "".join(json.dumps(row, ensure_ascii=False, sort_keys=True) + "\n" for row in rows)
    path.write_text(content, encoding="utf-8")


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