import io
import os
import subprocess
import tempfile
from typing import Tuple

_HEIC_EXTS  = {".heic", ".heif"}
_VIDEO_EXTS = {".mov", ".avi", ".m4v"}


def to_jpeg_if_heic(data: bytes, filename: str) -> Tuple[bytes, str]:
    """Convert HEIC/HEIF to JPEG; return (data, ext) unchanged for all other types."""
    ext = os.path.splitext(filename or "")[1].lower()
    if ext not in _HEIC_EXTS:
        return data, ext or ".jpg"
    try:
        import pillow_heif
        pillow_heif.register_heif_opener()
        from PIL import Image, ImageOps
        img = Image.open(io.BytesIO(data))
        img = ImageOps.exif_transpose(img)
        img = img.convert("RGB")
        buf = io.BytesIO()
        img.save(buf, format="JPEG", quality=90)
        return buf.getvalue(), ".jpg"
    except Exception:
        return data, ext


def to_mp4_if_needed(data: bytes, filename: str) -> Tuple[bytes, str]:
    """Convert MOV/AVI/M4V to H.264 MP4; return unchanged for MP4/WebM."""
    ext = os.path.splitext(filename or "")[1].lower()
    if ext not in _VIDEO_EXTS:
        return data, ext or ".mp4"
    src_path = dst_path = None
    try:
        with tempfile.NamedTemporaryFile(suffix=ext, delete=False) as src:
            src.write(data)
            src_path = src.name
        dst_path = src_path[: -len(ext)] + ".mp4"
        result = subprocess.run(
            ["ffmpeg", "-i", src_path,
             "-c:v", "libx264", "-preset", "fast", "-crf", "23",
             "-c:a", "aac",
             "-movflags", "+faststart",
             "-y", dst_path],
            capture_output=True, timeout=300,
        )
        if result.returncode == 0:
            with open(dst_path, "rb") as f:
                return f.read(), ".mp4"
        return data, ext
    except Exception:
        return data, ext
    finally:
        for p in [src_path, dst_path]:
            if p:
                try:
                    os.unlink(p)
                except OSError:
                    pass


def convert_media(data: bytes, filename: str) -> Tuple[bytes, str]:
    """Convert HEIC→JPEG and MOV/AVI/M4V→MP4; pass everything else through."""
    ext = os.path.splitext(filename or "")[1].lower()
    if ext in _HEIC_EXTS:
        return to_jpeg_if_heic(data, filename)
    if ext in _VIDEO_EXTS:
        return to_mp4_if_needed(data, filename)
    return data, ext or ".bin"


def extract_video_thumb(video_path: str) -> str | None:
    """Extract a frame at ~1s from video_path and save as <basename>_thumb.jpg.
    Returns the thumb path on success, None on failure."""
    base, _ = os.path.splitext(video_path)
    thumb_path = base + "_thumb.jpg"
    try:
        result = subprocess.run(
            ["ffmpeg", "-i", video_path,
             "-ss", "1", "-vframes", "1",
             "-q:v", "3", "-vf", "scale=480:-1",
             "-y", thumb_path],
            capture_output=True, timeout=30,
        )
        if result.returncode == 0 and os.path.exists(thumb_path):
            return thumb_path
        # Fallback: first frame (for videos shorter than 1s)
        result2 = subprocess.run(
            ["ffmpeg", "-i", video_path,
             "-vframes", "1",
             "-q:v", "3", "-vf", "scale=480:-1",
             "-y", thumb_path],
            capture_output=True, timeout=30,
        )
        return thumb_path if result2.returncode == 0 and os.path.exists(thumb_path) else None
    except Exception:
        return None