#!/usr/bin/env bash
set -euo pipefail

ROOT="$(cd "$(dirname "$0")/../.." && pwd)"
SVG="$ROOT/assets/Icon.svg"
OUT="${1:-$ROOT/build/AppIcon.icns}"

if [ ! -f "$SVG" ]; then
    echo "ERROR: $SVG not found" >&2
    exit 1
fi

if ! command -v rsvg-convert >/dev/null 2>&1; then
    echo "ERROR: rsvg-convert not on PATH (brew install librsvg)" >&2
    exit 1
fi

if ! command -v iconutil >/dev/null 2>&1; then
    echo "ERROR: iconutil not on PATH (macOS only)" >&2
    exit 1
fi

WORK_SVG="$(mktemp -t icon-svg.XXXXXX)"
ICONSET="$(mktemp -d -t iconset.XXXXXX)/AppIcon.iconset"
mkdir -p "$ICONSET"
trap 'rm -rf "$WORK_SVG" "$(dirname "$ICONSET")"' EXIT

# pulls the gradient labeled #bg-color and paints it across the whole viewBox under the existing artwork.
BG_FLAG=()
if grep -q 'id="bg-color"' "$SVG"; then
    VIEWBOX="$(grep -oE 'viewBox="[^"]+"' "$SVG" | head -1 | sed -E 's/viewBox="//;s/"$//')"
    read -r VBX VBY VBW VBH <<<"$VIEWBOX"
    INJECT="<rect x=\"${VBX}\" y=\"${VBY}\" width=\"${VBW}\" height=\"${VBH}\" fill=\"url(#bg-color)\"/>"
    awk -v inj="$INJECT" '/<\/defs>/ {print; print inj; next} {print}' "$SVG" > "$WORK_SVG"
    echo "Injected #bg-color full-canvas fill"
else
    cp "$SVG" "$WORK_SVG"
    BG_FLAG=(--background-color="${YRXTALS_ICON_BG:-black}")
    echo "No #bg-color id; falling back to solid ${YRXTALS_ICON_BG:-black}"
fi

ICNS_SIZES=(
    "16x16 16"
    "16x16@2x 32"
    "32x32 32"
    "32x32@2x 64"
    "128x128 128"
    "128x128@2x 256"
    "256x256 256"
    "256x256@2x 512"
    "512x512 512"
    "512x512@2x 1024"
)

for entry in "${ICNS_SIZES[@]}"; do
    name="${entry%% *}"
    size="${entry##* }"
    rsvg-convert "${BG_FLAG[@]}" --width="$size" --height="$size" "$WORK_SVG" -o "$ICONSET/icon_${name}.png"
done

mkdir -p "$(dirname "$OUT")"
iconutil -c icns "$ICONSET" -o "$OUT"

echo "Wrote $OUT"