#!/usr/bin/env bash
# Shared build paths; XBPS state is project-local, Rustup/Cargo also use user caches.
set -euo pipefail
export LC_ALL=C
FDS_ROOT=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)
FDS_VOID="$FDS_ROOT/vendor/void-packages"
FDS_XBPS="$FDS_ROOT/.host/xbps/usr/bin"

die() { printf 'ERROR: %s\n' "$*" >&2; exit 1; }
need() { command -v "$1" >/dev/null || die "Missing host command: $1 (see docs/build-host.md)"; }

check_void_pin() {
    local pin actual
    pin=$(cat "$FDS_ROOT/VOID_PACKAGES_COMMIT")
    [[ $pin =~ ^[0-9a-f]{40}$ ]] || die 'Invalid VOID_PACKAGES_COMMIT'
    [[ -f $FDS_VOID/xbps-src ]] || die 'Void submodule is missing; run make bootstrap'
    actual=$(git -C "$FDS_VOID" rev-parse HEAD)
    [[ $actual == "$pin" ]] || die "Void checkout mismatch: expected $pin, found $actual"
    git -C "$FDS_VOID" diff --quiet HEAD -- || die 'Tracked Void files were changed; keep FDS changes in packages/'
    export SOURCE_DATE_EPOCH
    SOURCE_DATE_EPOCH=$(git -C "$FDS_VOID" show -s --format=%ct HEAD)
}

# Keep the upstream entry point unchanged. Offline builds retain normal
# dependency resolution, but use only the restored local repositories.
xbps_src() {
    if [[ ${FDS_OFFLINE:-0} == 1 ]]; then
        [[ -f $FDS_ROOT/.host/frozen/lock.json ]] || die 'Offline builds require restored frozen inputs'
        ./xbps-src -N -n "$@"
    else
        ./xbps-src "$@"
    fi
}

fetch_rust_inputs() {
    local flags=()
    if [[ ${FDS_OFFLINE:-0} == 1 ]]; then
        flags=(--offline)
    fi
    cargo fetch --locked "${flags[@]}" --target aarch64-unknown-linux-musl --target x86_64-unknown-linux-gnu
}

use_xbps() {
    [[ -x $FDS_XBPS/xbps-install ]] || die 'Static XBPS tools are missing; run make bootstrap'
    export PATH="$FDS_XBPS:$PATH"
    # A musl-linked host tool must still build a glibc host container.
    export XBPS_ARCH=x86_64
}