# DOSBox-X with GDB stub support
# Multi-stage build for minimal final image

# =============================================================================
# Stage 1: Build DOSBox-X with GDB support
# =============================================================================
FROM debian:bookworm-slim AS builder

# Install build dependencies
RUN apt-get update && apt-get install -y --no-install-recommends \
    git \
    build-essential \
    automake \
    autoconf \
    libtool \
    pkg-config \
    patch \
    libsdl2-dev \
    libsdl2-net-dev \
    libsdl2-image-dev \
    libpng-dev \
    libpcap-dev \
    libslirp-dev \
    libfluidsynth-dev \
    libavcodec-dev \
    libavformat-dev \
    libavutil-dev \
    libswscale-dev \
    libncurses-dev \
    nasm \
    ca-certificates \
    && rm -rf /var/lib/apt/lists/*

# Clone DOSBox-X with remote debugging support (GDB server + QMP)
# This fork adds --enable-remotedebug which compiles in gdbserver.cpp and qmp.cpp
# Using rsp2k fork with GDB breakpoint address fix (uses physical addresses correctly)
# See: https://github.com/joncampbell123/dosbox-x/issues/752
#
# IMPORTANT: Clone and build MUST be in the same RUN to prevent BuildKit from
# caching the build step separately from the git clone step.
ARG CACHE_BUST=2026-01-28-v23-git-only
WORKDIR /build

# Configure and build with GDB server support
# --enable-remotedebug: Enables C_REMOTEDEBUG flag for GDB/QMP servers
# --enable-debug: Enables internal debugger (Alt+Pause)
# Note: Removed --disable-printer to enable parallel port support
# All patches are now committed to the rsp2k fork (joystick, parport, logging)
RUN echo "Cache bust: ${CACHE_BUST}" && \
    git clone --branch remotedebug --depth 1 https://github.com/rsp2k/dosbox-x-remotedebug.git dosbox-x && \
    cd dosbox-x && \
    ./autogen.sh && \
    ./configure \
        --prefix=/opt/dosbox-x \
        --enable-remotedebug \
        --enable-debug \
        --enable-sdl2 && \
    make -j$(nproc) && \
    make install

# =============================================================================
# Stage 2: Runtime image
# =============================================================================
FROM debian:bookworm-slim

# Install runtime dependencies only
RUN apt-get update && apt-get install -y --no-install-recommends \
    libsdl2-2.0-0 \
    libsdl2-net-2.0-0 \
    libsdl2-image-2.0-0 \
    libpng16-16 \
    libpcap0.8 \
    libslirp0 \
    libfluidsynth3 \
    libavcodec59 \
    libavformat59 \
    libavutil57 \
    libswscale6 \
    libgl1 \
    libx11-6 \
    libncurses6 \
    libxkbcommon0 \
    libxrandr2 \
    libxi6 \
    netcat-openbsd \
    && rm -rf /var/lib/apt/lists/*

# Copy DOSBox-X from builder
COPY --from=builder /opt/dosbox-x /opt/dosbox-x

# Create symlink in PATH
RUN ln -s /opt/dosbox-x/bin/dosbox-x /usr/local/bin/dosbox-x

# Create directories for config and DOS files
RUN mkdir -p /config /dos

# Default configuration for DOSBox-X
# Note: --enable-remotedebug compiles in the code, but these runtime settings enable the servers
RUN cat > /config/dosbox.conf << 'EOF'
[log]
logfile = /tmp/dosbox.log

[sdl]
fullscreen=false
windowresolution=800x600
output=opengl

[cpu]
# CRITICAL: Must use "normal" core for GDB breakpoints to work!
# Dynamic cores (auto/dynamic/dynamic_x86) bypass DEBUG_Breakpoint()
core=normal
cputype=auto
cycles=auto

[dosbox]
memsize=16
# Enable GDB remote debug server
gdbserver = true
gdbserver port = 1234
# Enable QMP (QEMU Machine Protocol) server for control
qmpserver = true
qmpserver port = 4444

[serial]
serial1=disabled
serial2=disabled

[autoexec]
# Mount /dos as C:
MOUNT C /dos
C:
EOF

# Expose ports:
# - 1234: GDB server (standard GDB remote protocol)
# - 4444: QMP server (QEMU Machine Protocol for control)
EXPOSE 1234 4444

# Set working directory
WORKDIR /dos

# Environment for X11 forwarding
ENV DISPLAY=:0

# Entry point
# Note: GDB/QMP servers are enabled via config file [dosbox] section
ENTRYPOINT ["dosbox-x", "-conf", "/config/dosbox.conf"]
CMD []