#!/bin/sh
# Which lines of the Rust the tests reach (#390, #394), inside the limits builds are held to.
#
#   sh scripts/coverage.sh            the cargo tests, all three crates, then their report
#   sh scripts/coverage.sh ipx-feed   one crate's cargo tests, then the report of what has run
#   sh scripts/coverage.sh api        the browser suite against an instrumented ipx and
#                                     ipx-directory: what the API and the daemon run (and the
#                                     page's coverage, which the same run measures)
#
# A coverage build instruments every crate, dependencies included, in a target of its own: a whole
# rebuild, the kind that took Tower down on 2026-11-04. So it builds in a container under the same
# cap as scripts/build-image.sh's builder (6 GB, six threads), past which the kernel kills it and
# production is left alone; and, as CLAUDE.md asks of tests, one crate at a time. If the cap kills
# it, say so and leave the cap be. The browser suite runs here, as it always does, its servers the
# container's build: the image is Ubuntu's, as code-server is, so they start here.
#
# Reports: target/coverage/cargo and target/coverage/api (summary.txt, a line a file; lcov.info;
# html/index.html), target/coverage/page (npm run coverage:page's, or api's). Each run ends by
# writing the numbers for Grafana (scripts/coverage-metrics.ts).
set -eu

MEM=6g
CPUS=0-5
NEED_KB=$((9 * 1024 * 1024))
MAX_LOAD=12
IMAGE=192.168.1.130:5000/ipx-coverage:latest
# The Docker daemon is Tower's, so its paths are Tower's: this tree is /mnt/user/vscode/ipx there,
# and target/ is a link to target-real on /mnt/fast (builds through /mnt/user's FUSE took the load
# to 248, CLAUDE.md). code-server sees /mnt/fast at the same path, so the instrumented binaries
# and the profiles they write are at the same place for both.
SRC=/mnt/user/vscode/ipx
TARGET=/mnt/fast/vscode/ipx/target-real
REGISTRY=$TARGET/coverage-registry
LLVM_TARGET=$TARGET/llvm-cov-target

cd "$(dirname "$0")/.."

room() {
  avail=$(awk '/^MemAvailable:/ {print $2}' /proc/meminfo)
  load=$(cut -d' ' -f1 /proc/loadavg)
  echo "MemAvailable $((avail / 1024)) MB, load $load"
  if [ "$avail" -lt "$NEED_KB" ]; then
    echo "refusing: under $((NEED_KB / 1024 / 1024)) GB available. Wait, or find what is using it." >&2
    exit 1
  fi
  if awk -v l="$load" -v m="$MAX_LOAD" 'BEGIN { exit !(l > m) }'; then
    echo "refusing: load over $MAX_LOAD. Wait for it to come down." >&2
    exit 1
  fi
}

run() {
  # The source read only: nothing in the tree is the coverage run's to change. The registry is
  # kept between runs, so the crates are downloaded once.
  docker run --rm --memory "$MEM" --memory-swap "$MEM" --cpuset-cpus "$CPUS" \
    -v "$SRC:/work:ro" -v "$TARGET:/target" -v "$REGISTRY:/usr/local/cargo/registry" \
    -e CARGO_TARGET_DIR=/target/llvm-cov-target -e CARGO_LLVM_COV_TARGET_DIR=/target/llvm-cov-target \
    "$IMAGE" "$@" || {
      code=$?
      [ "$code" -eq 137 ] && echo "killed at the ${MEM} memory cap: tell the user, do not raise it" >&2
      exit "$code"
    }
}

# The report of the profiles in the target, into target/coverage/$1, with the tree's own paths.
report() {
  room
  mkdir -p "$TARGET/coverage/$1"
  run sh -c "cargo llvm-cov report --lcov --output-path /target/coverage/$1/lcov.info \
    && cargo llvm-cov report --html --output-dir /target/coverage/$1 \
    && cargo llvm-cov report --summary-only > /target/coverage/$1/summary.txt"
  # The paths inside the container are /work/...; the tree's own, from here.
  sed -i 's#/work/##' "$TARGET/coverage/$1/summary.txt" "$TARGET/coverage/$1/lcov.info"
  tail -1 "$TARGET/coverage/$1/summary.txt"
}

docker pull -q "$IMAGE" >/dev/null
mkdir -p "$REGISTRY"

if [ "${1:-}" = api ]; then
  # Built as cargo-llvm-cov builds for a test of its own, instrumented, with no tests: the
  # binaries the browser suite starts. Profiles from an earlier run are not this one's.
  run cargo llvm-cov clean --workspace
  for p in ipx-directory ipx; do
    room
    echo "== build $p"
    run sh -c "eval \"\$(cargo llvm-cov show-env --export-prefix)\" && cargo build --locked -p $p"
  done
  room
  echo "== the browser suite"
  # Not `set -e`'s to stop on: a failing test still ran what it ran, and the report says so; the
  # suite's own exit code is this script's at the end.
  suite=0
  IPX_API_COVERAGE=$LLVM_TARGET IPX_COVERAGE=1 LLVM_PROFILE_FILE="$LLVM_TARGET/ipx-browser-%p-%14m.profraw" \
    npx playwright test || suite=$?
  ls "$LLVM_TARGET"/ipx-browser-*.profraw >/dev/null 2>&1 \
    || { echo "no profiles were written: did the servers stop on SIGTERM?" >&2; exit 1; }
  report api
  node scripts/coverage-metrics.ts
  exit "$suite"
fi

crates=${1:-ipx-feed ipx-directory ipx}
# A whole run starts from nothing; one crate adds to what has run.
[ $# -eq 0 ] && run cargo llvm-cov clean --workspace
for c in $crates; do
  room
  echo "== $c"
  run cargo llvm-cov --no-report --locked -p "$c"
done
report cargo
node scripts/coverage-metrics.ts