#!/usr/bin/env bash
#
# install_heic_thumbnailer.sh — enable HEIC/HEIF thumbnails in the Linux
# (GNOME/GTK, freedesktop) file chooser and file manager.
#
# Why this exists: OpenCV/Qt don't thumbnail HEIC, and GNOME's thumbnail
# system relies on the system libheif via gdk-pixbuf.  On distros with an
# old libheif (e.g. Ubuntu/Pop 22.04 ships 1.12), iPhone HDR HEICs fail to
# thumbnail ("Metadata not correctly assigned").  This installs a small
# thumbnailer backed by pillow-heif (which bundles a modern libheif) under
# /usr/local — where it is reachable inside GNOME's bwrap thumbnailer
# sandbox (the sandbox binds /usr but not $HOME, so a project venv won't do).
#
# Idempotent and safe to re-run.  Skips entirely when not needed:
#   - non-Linux (macOS etc. thumbnail HEIC natively), or
#   - the system already thumbnails HEIC (modern libheif present).
#
# Needs sudo for the /usr/local install; the registration is user-local.
#
#   ./scripts/install_heic_thumbnailer.sh
#
set -euo pipefail

PREFIX=/usr/local/lib/rectify-thumbnailer
THUMB_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/thumbnailers"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
TEST_HEIC="$SCRIPT_DIR/../tests/images/HEIC/IMG_0338.heic"

# 1. Linux only — other platforms handle HEIC natively (macOS Quick Look).
if [ "$(uname -s)" != "Linux" ]; then
    echo "Not Linux: HEIC thumbnails are handled natively here. Nothing to do."
    exit 0
fi

# 2. Already works natively?  If the stock gdk-pixbuf thumbnailer can render
#    our committed sample HEIC, the system libheif is new enough and this
#    helper is unnecessary.  (The sample lives under tests/, which is
#    export-ignored from source archives; if absent we just proceed.)
if command -v gdk-pixbuf-thumbnailer >/dev/null 2>&1 && [ -f "$TEST_HEIC" ]; then
    tmp="$(mktemp --suffix=.png)"
    if gdk-pixbuf-thumbnailer -s 128 "$TEST_HEIC" "$tmp" >/dev/null 2>&1 \
            && [ -s "$tmp" ]; then
        rm -f "$tmp"
        echo "System already thumbnails HEIC natively (modern libheif). Nothing to do."
        exit 0
    fi
    rm -f "$tmp"
fi

# 3. Install the pillow-heif decoder in an isolated venv under /usr/local.
echo "Installing the pillow-heif HEIC thumbnailer under $PREFIX (sudo required)…"
sudo install -d "$PREFIX"
if [ ! -x "$PREFIX/venv/bin/python3" ]; then
    sudo python3 -m venv "$PREFIX/venv"
fi
sudo "$PREFIX/venv/bin/pip" install -q --upgrade pip pillow-heif
sudo cp "$SCRIPT_DIR/heic_thumbnailer.py" "$PREFIX/thumbnailer.py"

# 4. Register with the freedesktop thumbnail system (user-local, no sudo).
mkdir -p "$THUMB_DIR"
cat > "$THUMB_DIR/rectify-heic.thumbnailer" <<EOF
[Thumbnailer Entry]
TryExec=$PREFIX/venv/bin/python3
Exec=$PREFIX/venv/bin/python3 $PREFIX/thumbnailer.py -s %s %i %o
MimeType=image/heif;image/heic;
EOF

# 5. Drop cached thumbnail failures so HEICs are retried.
rm -rf "${XDG_CACHE_HOME:-$HOME/.cache}/thumbnails/fail" 2>/dev/null || true

echo "Done.  HEIC thumbnails will appear in the file chooser and file manager."
echo "Restart the file manager to pick it up immediately:  nautilus -q"