#!/bin/sh
set -eu
root=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd -P)
case "$(uname -s)" in MINGW*|MSYS*|CYGWIN*) suffix=.exe ;; *) suffix= ;; esac
tool_dir="$root/.build/tools"
tool="$tool_dir/bd2w$suffix"

# Bootstrap only when the cached executable is absent. Build/run live in Go.
if [ ! -f "$tool" ]; then
    mkdir -p "$tool_dir"
    lock="$tool_dir/.bootstrap.lock"
    attempts=0
    while [ ! -f "$tool" ]; do
        if mkdir "$lock" 2>/dev/null; then
            temporary="$tool_dir/.bd2w-$$$suffix"
            trap 'rm -f "$temporary"; rmdir "$lock" 2>/dev/null || true' 0
            trap 'exit 130' INT TERM
            if [ ! -f "$tool" ]; then
                printf 'bd2w: compiling the build tool for first use...\n'
                (
                    cd "$root/go"
                    GOCACHE="$root/go/.cache/go-build"
                    GOOS=$(go env GOHOSTOS)
                    GOARCH=$(go env GOHOSTARCH)
                    CGO_ENABLED=0
                    export GOCACHE GOOS GOARCH CGO_ENABLED
                    go build -buildvcs=false -trimpath -o "$temporary" ./build
                )
                mv "$temporary" "$tool"
            fi
            rmdir "$lock"
            trap - 0 INT TERM
            break
        fi
        attempts=$((attempts + 1))
        if [ "$attempts" -ge 120 ]; then
            printf 'bd2w: bootstrap lock still held at %s; check the first launcher.\n' "$lock" >&2
            exit 1
        fi
        sleep 1
    done
fi
exec "$tool" "$@"