#!/usr/bin/env bash
# Rebuilds androidApp/src/main/res/font/nerd_icons.ttf.
#
# The app draws a handful of icons -- a folder, a git branch, a server, a
# cog -- as text in a Nerd Fonts glyph, rather than as vector assets or as
# ordinary Unicode. Unicode has no character for most of these, and the
# ones it does have are not reliably in an Android system font, so they
# land as tofu boxes on somebody's phone.
#
# The whole symbols font is 2.5 MB for the handful below, so what is
# committed is a subset. Add a codepoint to GLYPHS below and to NerdIcons.kt (the two
# lists have to agree -- a codepoint in the Kotlin but not here is a glyph
# that silently doesn't exist), then run this and commit the result.
#
# Needs python3 and network access; fontTools is fetched into a temporary
# venv, so nothing has to be installed on the machine.
set -euo pipefail

# Codepoint, then the Nerd Fonts glyph name it came from. All from the
# Material Design Icons set bar one, so they look like one family; the
# exception is noted on its own line.
GLYPHS=(
    U+F024B  # md-folder
    U+F062C  # md-source_branch
    U+F233   # fa-server
    U+F0493  # md-cog
    U+F0415  # md-plus
    U+F0450  # md-refresh
    U+F0A7A  # md-trash_can_outline
    U+F02D   # fa-book
    U+F0140  # md-chevron_down
)

url=https://github.com/ryanoasis/nerd-fonts/releases/latest/download/NerdFontsSymbolsOnly.zip
out="$(cd "$(dirname "$0")" && pwd)/androidApp/src/main/res/font/nerd_icons.ttf"
work="$(mktemp -d)"
trap 'rm -rf "$work"' EXIT

echo "Fetching $url"
curl -fsSL -o "$work/nf.zip" "$url"
python3 -c 'import sys,zipfile; zipfile.ZipFile(sys.argv[1]).extractall(sys.argv[2])' "$work/nf.zip" "$work"

python3 -m venv "$work/venv"
"$work/venv/bin/pip" -q install fonttools

unicodes="$(IFS=,; echo "${GLYPHS[*]}")"
mkdir -p "$(dirname "$out")"
# The Mono face: every glyph gets the same advance, so an icon occupies the
# same width whichever one it is and a row of them lines up with the row
# above. The proportional face varies the advance per glyph, which puts the
# text after each icon at a slightly different place.
"$work/venv/bin/pyftsubset" "$work/SymbolsNerdFontMono-Regular.ttf" \
    --unicodes="$unicodes" \
    --layout-features= \
    --drop-tables+=DSIG \
    --output-file="$out"

echo "Wrote $out ($(stat -c %s "$out") bytes) with ${#GLYPHS[@]} glyphs"