from __future__ import annotations

import json
import subprocess
from pathlib import Path
from typing import Any


def probe_video(path: str | Path, *, timeout_seconds: int = 30) -> dict[str, Any]:
    video_path = Path(path).expanduser().resolve(strict=False)
    base_record: dict[str, Any] = {
        "path": str(video_path),
        "status": "probe_failed",
        "retry_count": 0,
        "last_error": None,
    }
    command = [
        "ffprobe",
        "-v",
        "error",
        "-print_format",
        "json",
        "-show_format",
        "-show_streams",
        str(video_path),
    ]

    try:
        completed = subprocess.run(
            command,
            capture_output=True,
            text=True,
            check=True,
            timeout=timeout_seconds,
        )
        payload = json.loads(completed.stdout or "{}")
        video_stream = _first_video_stream(payload)
        format_info = payload.get("format", {})
        return {
            **base_record,
            "status": "probed",
            "duration_seconds": _optional_float(format_info.get("duration")),
            "codec_name": video_stream.get("codec_name"),
            "width": _optional_int(video_stream.get("width")),
            "height": _optional_int(video_stream.get("height")),
            "fps": _parse_frame_rate(
                video_stream.get("avg_frame_rate") or video_stream.get("r_frame_rate")
            ),
            "format_name": format_info.get("format_name"),
            "start_time": _optional_float(format_info.get("start_time")),
        }
    except subprocess.TimeoutExpired as exc:
        base_record["last_error"] = f"ffprobe timed out after {timeout_seconds}s"
        if exc.stderr:
            base_record["last_error"] += f": {exc.stderr}"
        return base_record
    except subprocess.CalledProcessError as exc:
        base_record["last_error"] = _error_text(exc.stderr or exc.stdout or str(exc))
        return base_record
    except (json.JSONDecodeError, ValueError) as exc:
        base_record["last_error"] = f"ffprobe parse failed: {exc}"
        return base_record


def _first_video_stream(payload: dict[str, Any]) -> dict[str, Any]:
    for stream in payload.get("streams", []):
        if stream.get("codec_type") == "video":
            return stream
    raise ValueError("ffprobe output did not contain a video stream")


def _parse_frame_rate(value: str | None) -> float | None:
    if not value or value == "0/0":
        return None
    if "/" in value:
        numerator, denominator = value.split("/", 1)
        denominator_value = float(denominator)
        if denominator_value == 0:
            return None
        return float(numerator) / denominator_value
    return float(value)


def _optional_float(value: Any) -> float | None:
    if value is None or value == "":
        return None
    return float(value)


def _optional_int(value: Any) -> int | None:
    if value is None or value == "":
        return None
    return int(value)


def _error_text(value: Any) -> str:
    if isinstance(value, bytes):
        return value.decode("utf-8", errors="replace").strip()
    return str(value).strip()