# Build stage - use native platform for fast builds
FROM --platform=$BUILDPLATFORM golang:1.25-bookworm AS builder

WORKDIR /build

# Cache dependencies separately from source code
COPY go.mod go.sum ./
RUN go mod download

# Copy source code
COPY . .

# Build for target platform with static binary
ARG TARGETOS TARGETARCH
RUN CGO_ENABLED=0 GOOS=${TARGETOS} GOARCH=${TARGETARCH} \
    go build -ldflags="-w -s" -o /server ./cmd/server

# Runtime stage - debian slim for debugging capability
FROM debian:bookworm-slim

# Create non-root user for security
RUN useradd -u 10001 -m appuser

# Switch to non-root user
USER appuser

# Copy binary from build stage
COPY --from=builder /server /usr/local/bin/server

# Declare data volume mount point
VOLUME /data

# Expose application port
EXPOSE 32768

# Run the server
CMD ["server"]