iconset

#!/usr/bin/env bash

set -e

tmp_dir=$(mktemp -d)
icons_data_file="Library/Icons.rb"
icons_dir="icons"
original_dir="icons/original"
preview_dir="icons/preview"
workflows_dir=".github/workflows"
count_total=0
count_step=0

function check() {
  command -v "$1" >/dev/null 2>&1
}

check convert || {
  echo "You need to install 'convert' tool as part of 'imagemagick'"
  exit 1
}

check png2icns || {
  echo "You need to install 'png2icns' tool as part of 'libicns'"
  exit 1
}

check sha256sum || {
  echo "You need to install 'sha256sum' tool"
  exit 1
}

function process() {
  local name="${1%.png}"
  local size="${#count_total}"
  local sha256=
  local icns_file="$icons_dir/${name}.icns"
  local workflow="${workflows_dir}/icon-${name}.yml"

  count_step=$((count_step+1))
  printf "[%${size}d/%d] %s\n" $count_step $count_total "$name"

  cp "${original_dir}/${name}.png" "${tmp_dir}/${name}.png"

  (
    cd "$tmp_dir"
    convert "${name}.png" -resize 1024x1024! "${name}_1024.png"
    convert "${name}.png" -resize  512x512!  "${name}_512.png"
    # convert "${name}.png" -resize  512x512!  "${name}_256@2x.png"
    convert "${name}.png" -resize  256x256!  "${name}_256.png"
    # convert "${name}.png" -resize  256x256!  "${name}_128@2x.png"
    convert "${name}.png" -resize  128x128!  "${name}_128.png"
    # convert "${name}.png" -resize   64x64!   "${name}_32@2x.png"
    convert "${name}.png" -resize   32x32!   "${name}_32.png"
    # convert "${name}.png" -resize   32x32!   "${name}_16@2x.png"
    convert "${name}.png" -resize   16x16!   "${name}_16.png"

    png2icns "${name}.icns" "${name}_1024.png" "${name}_512.png" "${name}_256.png" "${name}_128.png" "${name}_32.png" "${name}_16.png"
  )

  cp "${tmp_dir}/${name}.icns" "$icns_file"

  # since png contains time-related metadata and we want to avoid
  # dummy changes, let's copy preview ONLY when icns file changes
  if ! git diff --exit-code "$icns_file" >/dev/null ||
      ! git ls-files --error-unmatch "$icns_file" 2>/dev/null; then
    cp "${tmp_dir}/${name}_128.png" "$preview_dir/${name}_128.png"
  fi

  sha256=$(sha256sum "$icons_dir/${name}.icns" | cut -f 1 -d " ")
  echo "  \"$name\" => \"$sha256\"," >> "$icons_data_file"

  cat <<EOT > "$workflow"
# This file is automatically generated by iconset script.
#
# DO NOT MODIFY it manually.

name: Icon $name

on:
  push:
    branches:
      - master
    paths:
      - "$icons_dir/${name}.icns"
      - "$workflow"
  pull_request:
    paths:
      - "$icons_dir/${name}.icns"
      - "$workflow"

jobs:
  build:
    runs-on: macos-11
    env:
      HOMEBREW_GITHUB_REF: \${{ github.head_ref || github.ref }}
      HOMEBREW_GITHUB_REPOSITORY: \${{ github.repository }}
      HOMEBREW_GITHUB_ACTOR: \${{ github.actor }}

    steps:
      - uses: actions/checkout@v3

      - name: Build emacs-plus with $name icon
        run: brew install Aliases/\$(readlink Aliases/emacs-plus) --with-$name-icon

      - name: Test installation
        run: \$(brew --prefix)/bin/emacs --batch --eval='(print (+ 2 2))'
EOT
}

for f in "$original_dir"/*.png; do
  count_total=$((count_total+1))
done

for f in "${workflows_dir}"/icon-*.yml; do
  rm "$f"
done

rm "$icons_data_file"
echo "ICONS_CONFIG = {" >> "$icons_data_file"

for f in "$original_dir"/*.png; do
  process "${f#"$original_dir"/}"
done

echo "}.freeze" >> "$icons_data_file"

echo "-> done."