#!/bin/bash
# Builds libm3ui.so against an upstream Fcitx5 source tree of the same version
# as the Fcitx5 installed on this system. The addon needs Fcitx5's internal
# Wayland protocol wrappers, which are not part of fcitx5-devel, so it is built
# inside the upstream tree.
set -euo pipefail

root=$(cd "$(dirname "$0")/.." && pwd)
work=${WORK_DIR:-$root/build}
version=${FCITX_VERSION:-$(pkg-config --modversion Fcitx5Core)}

die() { echo "build.sh: $*" >&2; exit 1; }
command -v git >/dev/null || die "git is needed to fetch the sources"

# The sources are fetched by commit hash and the hash is checked afterwards. A
# tag can be moved and a downloaded archive can be swapped, a commit hash cannot
# be faked, Git verifies the content against it. This plugin runs inside the
# input method and sees everything that is typed, so what it is built from
# matters.
#
# Commit the Fcitx5 release tag points to, check it yourself when adding one:
#   git ls-remote https://github.com/fcitx/fcitx5 "refs/tags/<version>^{}"
declare -A known_commits=(
    ["5.1.23"]="27cca6e0239938b2d53937061d0980c087856b22"
)
commit=${FCITX_COMMIT:-${known_commits[$version]:-}}
[ -n "$commit" ] || die "no pinned commit for Fcitx5 $version. Look up the commit of its tag and pass it as FCITX_COMMIT=<sha>"
# Commit of the yoga submodule pinned by Fcitx5 (third_party/yoga).
yoga_commit=${YOGA_COMMIT:-042f5013152eb81c1552dec945b88f7b95ca350f}

# fetch_commit <url> <dir> <commit>, leaves <dir> checked out at exactly <commit>
fetch_commit() {
    local url=$1 dir=$2 want=$3
    if [ -d "$dir/.git" ] && [ "$(git -C "$dir" rev-parse HEAD 2>/dev/null)" = "$want" ]; then
        return 0
    fi
    rm -rf "$dir"
    mkdir -p "$dir"
    git -C "$dir" init -q
    git -C "$dir" fetch -q --depth 1 "$url" "$want" || die "could not fetch $want from $url"
    git -C "$dir" checkout -q FETCH_HEAD
    [ "$(git -C "$dir" rev-parse HEAD)" = "$want" ] || die "$url gave a different commit than $want"
}

srcdir=$work/fcitx5-$version
mkdir -p "$work"
echo ">> fetching Fcitx5 $version ($commit)"
fetch_commit https://github.com/fcitx/fcitx5 "$srcdir" "$commit"
echo ">> fetching yoga ($yoga_commit)"
fetch_commit https://github.com/facebook/yoga "$srcdir/third_party/yoga" "$yoga_commit"
[ -z "${FETCH_ONLY:-}" ] || { echo ">> sources are in place"; exit 0; }

echo ">> overlaying m3ui"
rm -rf "$srcdir/src/ui/m3ui"
cp -r "$root/src" "$srcdir/src/ui/m3ui"
if ! grep -q 'add_subdirectory(m3ui)' "$srcdir/src/ui/CMakeLists.txt"; then
    sed -i 's/^add_subdirectory(classic)$/add_subdirectory(classic)\nadd_subdirectory(m3ui)/' \
        "$srcdir/src/ui/CMakeLists.txt"
fi

echo ">> configuring"
cmake -S "$srcdir" -B "$work/cmake" -G Ninja \
    -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_INSTALL_PREFIX="${PREFIX:-$HOME/.local/m3ui}" \
    -DENABLE_X11=On -DENABLE_WAYLAND=On \
    -DENABLE_TEST=Off -DENABLE_TESTING_ADDONS=Off -DENABLE_ENCHANT=Off \
    -DENABLE_DOC=Off -DENABLE_XDGAUTOSTART=Off -DENABLE_EMOJI=Off

echo ">> building"
ninja -C "$work/cmake" m3ui src/ui/m3ui/m3ui.conf
echo ">> done, run scripts/install.sh"