#!/usr/bin/env bash
# Generate a legacy-format fontconfig.properties for Webswing's app JVM.
#
# Why this exists: OpenJDK 9+ stopped shipping lib/fontconfig.bfc and queries
# libfontconfig at runtime instead. Webswing's WebFontConfiguration still extends
# the legacy sun.awt.FontConfiguration, which reads the old properties file. With
# no such file the app JVM dies at startup with "Fontconfig head is null". The JVM
# honours -Dsun.awt.fontconfig=<path>, so we generate one.
#
# Font choice matters as much as existence. MegaMek draws armor pips, heat
# markers and status icons with symbol codepoints, and Noto Sans covers almost
# none of them (of the 18 codepoints MegaMek uses, Noto Sans has exactly one:
# U+00B0). Those render as boxes. So:
#
#   base      DejaVu - broad symbol coverage on top of normal text
#   fallback  Noto Sans Symbols2         U+2B1D armor pips, U+2744, U+2B71/73
#             Material Symbols Rounded   MegaMek's bundled Private Use icons
#
# Do NOT add "Noto Sans Symbols" (no 2) as a further fallback for U+23AF. Its
# family name is a prefix of "Noto Sans Symbols2" and the legacy parser
# mis-resolves between them: basic punctuation (/ : , parens) starts rendering as
# boxes and the armor pips disappear. Verified by screenshot, and reverted.
#
# Verify coverage changes with the GlyphCoverage probe rather than by eye.
set -euo pipefail

ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
OUT="${1:-$ROOT/spike-webswing/fontconfig.properties}"
MM_HOME="${MM_HOME:-$ROOT/MegaMek-0.51.00}"
mkdir -p "$(dirname "$OUT")"

command -v fc-match >/dev/null || { echo "ERROR: fc-match not found (install fontconfig)" >&2; exit 1; }

resolve() { fc-match -f '%{file}' "$1" 2>/dev/null || true; }
xlfd()    { printf -- '-*-%s-%s-%s-normal--*-%%d-*-*-p-*-%s' "$1" "$2" "$3" "$4"; }
key()     { printf 'filename.%s' "$(printf '%s' "$1" | tr ' ' '_')"; }

# DejaVu rather than Noto: it carries the symbol coverage MegaMek needs.
declare -A FAMILY=(
  [serif]="DejaVu Serif"
  [sansserif]="DejaVu Sans"
  [monospaced]="DejaVu Sans Mono"
  [dialog]="DejaVu Sans"
  [dialoginput]="DejaVu Sans Mono"
)

{
  echo "# Generated by scripts/gen-fontconfig.sh - do not edit by hand."
  echo "version=1"
  echo
  echo "sequence.allfonts=latin-1"
  echo "sequence.fallback=symbols2,micons"
  echo
} > "$OUT"

# Component fonts: <logical>.<style>.latin-1
for logical in serif sansserif monospaced dialog dialoginput; do
  famlc="$(echo "${FAMILY[$logical]}" | tr '[:upper:]' '[:lower:]')"
  for style in plain bold italic bolditalic; do
    case "$style" in
      plain)      w=regular; s=r ;;
      bold)       w=bold;    s=r ;;
      italic)     w=regular; s=i ;;
      bolditalic) w=bold;    s=i ;;
    esac
    echo "${logical}.${style}.latin-1=$(xlfd "$famlc" "$w" "$s" iso8859-1)" >> "$OUT"
  done
done

# Fallbacks apply to every logical font, hence allfonts.<charset>.
SYMBOLS_XLFD="$(xlfd 'noto sans symbols2' regular r iso10646-1)"
ICONS_XLFD="$(xlfd 'material symbols rounded' regular r iso10646-1)"
{
  echo
  echo "allfonts.symbols2=$SYMBOLS_XLFD"
  echo "allfonts.micons=$ICONS_XLFD"
  echo
} >> "$OUT"

# Font file names.
declare -A SEEN=()
for logical in serif sansserif monospaced dialog dialoginput; do
  fam="${FAMILY[$logical]}"
  famlc="$(echo "$fam" | tr '[:upper:]' '[:lower:]')"
  for style in plain bold italic bolditalic; do
    case "$style" in
      plain)      w=regular; s=r; spec="$fam:regular" ;;
      bold)       w=bold;    s=r; spec="$fam:bold" ;;
      italic)     w=regular; s=i; spec="$fam:italic" ;;
      bolditalic) w=bold;    s=i; spec="$fam:bold:italic" ;;
    esac
    k="$(key "$(xlfd "$famlc" "$w" "$s" iso8859-1)")"
    [ -n "${SEEN[$k]:-}" ] && continue
    path="$(resolve "$spec")"
    if [ -z "$path" ] || [ ! -f "$path" ]; then
      echo "WARN: no font for '$spec', skipping" >&2
      continue
    fi
    echo "${k}=${path}" >> "$OUT"
    SEEN[$k]=1
  done
done

# Symbol fallback: system-installed.
SYM_PATH="$(resolve 'Noto Sans Symbols2')"
if [ -n "$SYM_PATH" ] && [ -f "$SYM_PATH" ]; then
  echo "$(key "$SYMBOLS_XLFD")=$SYM_PATH" >> "$OUT"
else
  echo "WARN: Noto Sans Symbols2 not found - armor pips will render as boxes" >&2
fi

# Icon fallback: shipped inside MegaMek, so fc-match cannot see it. Referenced by
# path, which means MM_HOME/data/fonts must be in -Dwebswing.trustedFontDirs.
ICONS_PATH="$(find "$MM_HOME/data/fonts/Icons" -name '*.ttf' 2>/dev/null | head -1)"
if [ -n "$ICONS_PATH" ]; then
  echo "$(key "$ICONS_XLFD")=$ICONS_PATH" >> "$OUT"
else
  echo "WARN: MegaMek Icons font not found under $MM_HOME/data/fonts/Icons" >&2
fi

echo "wrote $OUT ($(grep -c . "$OUT") lines)"