# =========================================================================
# Stage 1: Native Host Builder
# We use --platform=$BUILDPLATFORM so the container runs natively on your
# Mac's ultra-fast CPU instead of running slow ARM-to-Intel emulation.
# =========================================================================
FROM --platform=$BUILDPLATFORM rust:slim AS builder

# Install linkers and cross-compilers for Linux ARM64, Linux x86, and Windows
RUN apt-get update && apt-get install -y \
    build-essential \
    gcc-aarch64-linux-gnu \
    gcc-x86-64-linux-gnu \
    mingw-w64 \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /workspace
COPY . .

# Capture target arguments from the docker buildx flag
ARG TARGETOS
ARG TARGETARCH

# Dynamically cross-compile based on the platform requested by Buildx
RUN set -ex; \
    if [ "$TARGETOS" = "linux" ] && [ "$TARGETARCH" = "amd64" ]; then \
        rustup target add x86_64-unknown-linux-gnu; \
        export CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_LINKER=x86_64-linux-gnu-gcc; \
        cargo build --release --target x86_64-unknown-linux-gnu; \
        mkdir -p /out; cp target/x86_64-unknown-linux-gnu/release/libtbr.so /out/; \
    \
    elif [ "$TARGETOS" = "linux" ] && [ "$TARGETARCH" = "arm64" ]; then \
        rustup target add aarch64-unknown-linux-gnu; \
        export CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER=aarch64-linux-gnu-gcc; \
        cargo build --release --target aarch64-unknown-linux-gnu; \
        mkdir -p /out; cp target/aarch64-unknown-linux-gnu/release/libtbr.so /out/; \
    \
    elif [ "$TARGETOS" = "windows" ] && [ "$TARGETARCH" = "amd64" ]; then \
        rustup target add x86_64-pc-windows-gnu; \
        cargo build --release --target x86_64-pc-windows-gnu; \
        mkdir -p /out; \
        # Copy the compiled Windows DLL (supports both prefixed and non-prefixed outputs) \
        cp target/x86_64-pc-windows-gnu/release/*.dll /out/tbr.dll; \
    fi

# =========================================================================
# Stage 2: Exporter Stage
# =========================================================================
FROM scratch AS exporter
ARG TARGETOS
ARG TARGETARCH
# Copies the binaries into cleanly structured, platform-named folders
COPY --from=builder /out/ /