# syntax=docker/dockerfile:1
# =============================================================================
# Multi-stage Dockerfile for pg_trickle E2E coverage measurement.
#
# Identical to Dockerfile.e2e but compiles with LLVM coverage instrumentation
# so that profraw files are generated when PostgreSQL exercises the extension.
#
# Stage 1 (builder): Compiles the extension with -C instrument-coverage
# Stage 2 (runtime):  Runs PostgreSQL with the instrumented .so, writing
#                      profraw files to /coverage inside the container.
#
# Usage:
#   docker build -t pg_trickle_e2e_cov:latest \
#       -f tests/Dockerfile.e2e-coverage .
#
# The build context must be the project root (parent of tests/).
# =============================================================================

# ── Stage 1: Build the extension with coverage instrumentation ──────────────
FROM postgres:18.3 AS builder

# Install build dependencies
RUN apt-get update && apt-get install -y --no-install-recommends \
        curl \
        build-essential \
        libreadline-dev \
        zlib1g-dev \
        pkg-config \
        libssl-dev \
        libclang-dev \
        clang \
        postgresql-server-dev-18 \
        ca-certificates \
        git \
    && rm -rf /var/lib/apt/lists/*

# Install Rust toolchain (stable)
RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
    | sh -s -- -y --default-toolchain stable
ENV PATH="/root/.cargo/bin:${PATH}"

# Install llvm-tools-preview for profdata/cov binaries
RUN rustup component add llvm-tools-preview

# Install cargo-pgrx (layer-cached; only re-runs if the version changes).
RUN --mount=type=cache,target=/root/.cargo/registry \
    --mount=type=cache,target=/root/.cargo/git \
    cargo install --locked cargo-pgrx --version 0.17.0

# Initialize pgrx for PG 18 using the system pg_config (layer-cached)
RUN cargo pgrx init --pg18 /usr/bin/pg_config

# ── Dependency caching layer ────────────────────────────────────────────────
WORKDIR /build
COPY Cargo.toml Cargo.lock ./

RUN mkdir -p src/bin src/dvm/operators benches && \
    echo '#![allow(warnings)] fn main() {}' > src/bin/pgrx_embed.rs && \
    echo '#![allow(warnings)]' > src/lib.rs && \
    echo '' > src/dvm/mod.rs && \
    echo '' > src/dvm/operators/mod.rs && \
    echo '' > src/ivm.rs && \
    echo 'fn main() {}' > benches/refresh_bench.rs && \
    echo 'fn main() {}' > benches/diff_operators.rs

RUN --mount=type=cache,target=/root/.cargo/registry \
    --mount=type=cache,target=/root/.cargo/git \
    cargo fetch

# ── Build the real extension with coverage instrumentation ──────────────────
COPY src/ src/
COPY pg_trickle.control ./

# Enable LLVM source-based code coverage.
# Cache mount on target/ keeps incremental artefacts between builds.
ENV RUSTFLAGS="-C instrument-coverage"
RUN --mount=type=cache,target=/root/.cargo/registry \
    --mount=type=cache,target=/root/.cargo/git \
    --mount=type=cache,target=/build/target \
    cargo pgrx package --pg-config /usr/bin/pg_config && \
    mkdir -p /artefacts && \
    cp -r target/release/pg_trickle-pg18 /artefacts/

# Verify the artifacts were produced
RUN echo "=== Coverage-instrumented package artifacts ===" && \
    find /artefacts/pg_trickle-pg18 -type f && \
    echo "========================="

# Copy llvm-profdata into a well-known location for the final image.
# The binary lives under rustc's sysroot — find it dynamically.
RUN SYSROOT="$(rustc --print sysroot)" && \
    PROFDATA="$(find "$SYSROOT" -name llvm-profdata -type f | head -1)" && \
    if [ -n "$PROFDATA" ]; then \
        cp "$PROFDATA" /usr/local/bin/llvm-profdata; \
        echo "llvm-profdata copied from $PROFDATA"; \
    else \
        echo "WARNING: llvm-profdata not found — combined merge will need host toolchain"; \
    fi

# ── Stage 2: Runtime image with instrumented extension ──────────────────────
FROM postgres:18.3

LABEL org.opencontainers.image.title="pg_trickle E2E coverage image"
LABEL org.opencontainers.image.description="PostgreSQL 18.3 with coverage-instrumented pg_trickle"

# Copy extension artifacts from the builder stage
COPY --from=builder \
    /artefacts/pg_trickle-pg18/usr/share/postgresql/18/extension/ \
    /usr/share/postgresql/18/extension/

COPY --from=builder \
    /artefacts/pg_trickle-pg18/usr/lib/postgresql/18/lib/ \
    /usr/lib/postgresql/18/lib/

# Copy llvm-profdata for optional in-container merge
COPY --from=builder /usr/local/bin/llvm-profdata /usr/local/bin/

# Create a world-writable directory for profraw output.
# The postgres user (uid 999) writes here; the host user reads from the
# bind-mounted directory.
RUN mkdir -p /coverage && chmod 777 /coverage

# Tell the LLVM runtime to write profraw files into /coverage.
# %p = PID, %m = binary signature hash — avoids collisions across processes.
ENV LLVM_PROFILE_FILE="/coverage/pgs-%p-%m.profraw"

# Configure shared_preload_libraries
RUN echo "" >> /usr/share/postgresql/postgresql.conf.sample && \
    echo "# pg_trickle E2E coverage configuration" >> /usr/share/postgresql/postgresql.conf.sample && \
    echo "shared_preload_libraries = 'pg_trickle'" >> /usr/share/postgresql/postgresql.conf.sample

# Verify the extension files are in place
RUN ls -la /usr/share/postgresql/18/extension/pg_trickle* && \
    ls -la /usr/lib/postgresql/18/lib/pg_trickle*

EXPOSE 5432