"""
ffmpeg / ffprobe discovery and probing helpers.
Shared by both concat and singing detection features.
"""

import json
import os
import shutil
import subprocess
import sys
from pathlib import Path

# ── Suppress console windows on Windows ──────────────────────────────────────
_NO_WINDOW: dict = {}
if sys.platform == "win32":
    _NO_WINDOW["creationflags"] = subprocess.CREATE_NO_WINDOW


def app_dir() -> str:
    if getattr(sys, "frozen", False):
        return os.path.dirname(sys.executable)
    return os.path.dirname(os.path.abspath(__file__))


def find_tool(name: str) -> str | None:
    """Locate ffmpeg / ffprobe next to the exe / script, then on PATH."""
    base = app_dir()
    for sub in ["_internal", "..", ""]:
        for variant in [name + ".exe", name]:
            p = os.path.join(base, sub, variant)
            if os.path.exists(p):
                return os.path.abspath(p)
    return shutil.which(name + ".exe") or shutil.which(name)


def probe_duration(path: str, ffprobe_bin: str | None = None) -> float:
    """Get video/audio duration in seconds via ffprobe."""
    ffprobe = ffprobe_bin or find_tool("ffprobe")
    if not ffprobe:
        return 0.0
    try:
        r = subprocess.run(
            [ffprobe, "-v", "error",
             "-show_entries", "format=duration",
             "-of", "json", path],
            stdout=subprocess.PIPE, stderr=subprocess.PIPE,
            text=True, timeout=20,
            **_NO_WINDOW,
        )
        if r.returncode != 0:
            return 0.0
        data = json.loads(r.stdout or "{}")
        return max(0.0, float(data.get("format", {}).get("duration", 0) or 0))
    except Exception:
        return 0.0


def extract_audio(video_path: str, output_wav: str,
                  ffmpeg_bin: str | None = None,
                  progress_cb=None) -> str:
    """
    Extract audio from video file as 16kHz mono WAV.
    Required format for inaSpeechSegmenter.
    
    progress_cb: optional callable(message: str) for status updates.
    """
    ffmpeg = ffmpeg_bin or find_tool("ffmpeg")
    if not ffmpeg:
        raise FileNotFoundError("ffmpeg not found. Install ffmpeg and add to PATH.")

    if progress_cb:
        progress_cb(f"Extracting audio from: {Path(video_path).name}")

    cmd = [
        ffmpeg,
        "-i", video_path,
        "-vn",
        "-acodec", "pcm_s16le",
        "-ar", "16000",
        "-ac", "1",
        "-y",
        output_wav,
    ]

    result = subprocess.run(
        cmd,
        capture_output=True,
        text=True,
        timeout=1800,
        **_NO_WINDOW,
    )
    if result.returncode != 0:
        raise RuntimeError(f"ffmpeg failed:\n{result.stderr[-500:]}")

    if progress_cb:
        size_mb = os.path.getsize(output_wav) / (1024 * 1024)
        progress_cb(f"Audio extracted: {size_mb:.1f} MB")

    return output_wav