"""
Helpers for inlining local image files (PNG, SVG, etc.) as base64 HTML <img> tags.
Use inline_img() anywhere you need an image inside st.markdown(unsafe_allow_html=True).
"""
import base64
from pathlib import Path

_MIME = {
    ".svg": "image/svg+xml",
    ".png": "image/png",
    ".jpg": "image/jpeg",
    ".jpeg": "image/jpeg",
    ".gif": "image/gif",
    ".webp": "image/webp",
}


def inline_img(path: Path | str, height: str = "1.2em", *, fallback: str = "", extra_style: str = "") -> str:
    """
    Return an HTML <img> tag with the file base64-encoded into the src.

    Args:
        path:        Absolute or relative path to the image file.
        height:      CSS height value (e.g. "1.2em", "24px"). Width scales automatically.
        fallback:    String to return if the file does not exist (e.g. an emoji).
        extra_style: Additional CSS to append to the style attribute.

    Returns:
        HTML string safe to embed inside st.markdown(unsafe_allow_html=True).
    """
    p = Path(path)
    if not p.exists():
        return fallback

    mime = _MIME.get(p.suffix.lower(), "image/png")
    b64 = base64.b64encode(p.read_bytes()).decode()
    style = f"height:{height};vertical-align:middle;display:inline-block;margin:0 3px;"
    if extra_style:
        style += extra_style
    return f"<img src='data:{mime};base64,{b64}' style='{style}'/>"