# Lint stage — fast feedback on formatting and lint issues.
# The golangci-lint image bundles Go, gcc and make, so it can run go vet on
# the CGO sqlite package and golangci-lint without extra installs.
# golangci/golangci-lint:v2.7.2 (Go 1.25.5), 2026-09-21
FROM golangci/golangci-lint@sha256:5d6d5c70a61f1356adfd9dd6316ce286799fefc9d743421356ff1b00842368ba AS lint

WORKDIR /src

COPY go.mod go.sum ./
RUN go mod download

COPY . .

RUN make fmt-check
RUN make lint

# Build stage
# golang:1.24-bookworm, 2026-09-21
FROM golang@sha256:1a6d4452c65dea36aac2e2d606b01b4a029ec90cc1ae53890540ce6173ea77ac AS builder

# Install build dependencies (zstd for archive, gcc for CGO/sqlite3)
RUN apt-get update && apt-get install -y --no-install-recommends \
    zstd \
    gcc \
    libc6-dev \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /src

# Force BuildKit to run the lint stage before compiling or testing.
COPY --from=lint /src/go.sum /dev/null

# Copy everything
COPY . .

# Vendor dependencies (must be after copying source)
RUN go mod download && go mod vendor

# Run the test suite in the build stage: -race needs cgo and the C compiler
# installed above. The suite is offline (the live-feed test is opt-in).
RUN make test

# Build the binary with CGO enabled (required for sqlite3)
RUN CGO_ENABLED=1 GOOS=linux go build -o /routewatch ./cmd/routewatch

# Create source archive with vendored dependencies
RUN tar --zstd -cf /routewatch-source.tar.zst \
    --exclude='.git' \
    --exclude='*.tar.zst' \
    .

# Runtime stage
# debian:bookworm-slim, 2026-09-21
FROM debian@sha256:3783cc01769c7b2b1b83a5c5ad96c815348e28ed7da68e2e3687004faa906251

# Install runtime dependencies
# - ca-certificates: for HTTPS connections
# - curl: for health checks
RUN apt-get update && apt-get install -y --no-install-recommends \
    ca-certificates \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Create non-root user
RUN useradd -r -u 1000 -m routewatch

RUN mkdir -p /var/lib/berlin.sneak.app.routewatch && chown routewatch:routewatch /var/lib/berlin.sneak.app.routewatch

RUN mkdir /app
WORKDIR /app

# Copy binary and source archive from builder
COPY --from=builder /routewatch /app/routewatch
COPY --from=builder /routewatch-source.tar.zst /app/source/routewatch-source.tar.zst

# Set ownership
RUN chown -R routewatch:routewatch /app

ENV XDG_DATA_HOME=/var/lib

# Cap the Go heap at 1.5 GiB so the runtime collects harder before the
# container's memory limit is reached. runuser preserves this the way it does
# XDG_DATA_HOME above.
ENV GOMEMLIMIT=1536MiB

# Cap glibc's malloc arenas. The SQLite C library allocates and frees millions
# of small page-cache chunks from many threads; glibc otherwise creates up to
# eight arenas per core (hundreds on a large host) and keeps each arena's freed
# chunks resident, so process RSS climbs far above SQLite's live heap and never
# comes back down. Two arenas keep that retained memory bounded; database writes
# are already serialized, so the lost allocator concurrency costs nothing here.
ENV MALLOC_ARENA_MAX=2

# Expose HTTP port
EXPOSE 8080

COPY ./entrypoint.sh /entrypoint.sh

# Health check using the health endpoint, on the port PORT names
HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
    CMD curl -sf "http://localhost:${PORT:-8080}/.well-known/healthcheck.json" || exit 1

ENTRYPOINT ["/bin/bash", "/entrypoint.sh" ]