import shutil
import subprocess
from pathlib import Path

from .file_utils import resolve_path


def check_ffmpeg():
    ffmpeg = shutil.which("ffmpeg") or shutil.which("ffmpeg.exe")
    if ffmpeg is None:
        raise RuntimeError("ffmpeg not found. Please install ffmpeg and add it to PATH.")
    return ffmpeg


def run_ffmpeg(args, error_label):
    ffmpeg = check_ffmpeg()
    command = [ffmpeg] + [str(arg) for arg in args]
    result = subprocess.run(command, capture_output=True, text=True)
    if result.returncode != 0:
        stderr = result.stderr.strip()
        raise RuntimeError(f"{error_label} failed with exit code {result.returncode}: {stderr}")


def convert_video_to_25fps(input_path, output_path):
    input_file = resolve_path(input_path)
    output_file = resolve_path(output_path)
    output_file.parent.mkdir(parents=True, exist_ok=True)
    run_ffmpeg(
        [
            "-y",
            "-i",
            input_file,
            "-r",
            "25",
            "-an",
            "-c:v",
            "libx264",
            "-pix_fmt",
            "yuv420p",
            "-crf",
            "18",
            output_file,
        ],
        "25fps video conversion",
    )
    return output_file


def convert_audio_to_16k_wav(input_path, output_path):
    input_file = resolve_path(input_path)
    output_file = resolve_path(output_path)
    output_file.parent.mkdir(parents=True, exist_ok=True)
    run_ffmpeg(
        [
            "-y",
            "-i",
            input_file,
            "-vn",
            "-ac",
            "1",
            "-ar",
            "16000",
            "-acodec",
            "pcm_s16le",
            output_file,
        ],
        "16kHz audio conversion",
    )
    return output_file