PROJECT_ID="$1"
PROJECT_NAMESPACE="$2"
PROJECT_NAME="$3"
RELEASE_COMMIT="$4"
RELEASE_TAG="$5"
RELEASE_TIME="$6"

: "${PIGEON_GITLAB_TOKEN:?}"
: "${PIGEON_PROJECTS:?}"
: "${PIGEON_STATE:?}"

RATE_LIMIT=3

PIGEON_DATABASE="$(realpath -m "$PIGEON_STATE/db")"
RELEASE_TIME="$(date -d "$RELEASE_TIME" '+%Y-%m-%d %H:%M:%S' 2>/dev/null || true)"

report() {
  curl -s --show-error --out-null --request PUT \
    --header "PRIVATE-TOKEN: $PIGEON_GITLAB_TOKEN" \
    --header 'Content-Type: application/json' \
    --data "$(jq -n --arg d "$1" '{"description": $d}')" \
    --url "https://gitlab.com/api/v4/projects/$PROJECT_ID/releases/$RELEASE_TAG"
}
db() {
  sqlite3 -bail -cmd '.timeout 10000' "$PIGEON_DATABASE" "$@"
}
q() {
  printf "'%s'" "$(printf %s "$1" | sed "s/'/''/g")"
}

db << 'EOF'
CREATE TABLE IF NOT EXISTS results (
    id      INTEGER PRIMARY KEY,
    student TEXT NOT NULL,
    project TEXT NOT NULL,
    hash    TEXT NOT NULL,
    time    TEXT NOT NULL DEFAULT (datetime('now')),
    score   INTEGER CHECK (score >= 0)
);
EOF

ROW="$(db <<EOF
INSERT INTO results (student, project, hash, time)
SELECT $(q "$PROJECT_NAMESPACE"), $(q "$PROJECT_NAME"), $(q "$RELEASE_COMMIT"),
  COALESCE(NULLIF($(q "$RELEASE_TIME"), ''), datetime('now'))
WHERE (SELECT COUNT(*) FROM results
  WHERE student = $(q "$PROJECT_NAMESPACE") AND project = $(q "$PROJECT_NAME")
  AND time > datetime('now', '-1 day')) < $RATE_LIMIT
RETURNING id;
EOF
)"

if [ -z "$ROW" ] ; then
  report "Rate limit exceeded!"
  exit
fi

DIRECTORY="$(mktemp -d /tmp/pigeon.XXXXXXXXXX)"
trap 'rm -rf "$DIRECTORY"' EXIT
cd "$DIRECTORY"

git -c advice.detachedHead=false clone -q --rev "$RELEASE_COMMIT" --depth 1 \
  "https://oauth2:$PIGEON_GITLAB_TOKEN@gitlab.com/$PROJECT_NAMESPACE/$PROJECT_NAME.git" student/
rm -rf student/.git

mkdir -p project/tests project/build
cp -a "$PIGEON_PROJECTS/$PROJECT_NAME"/tests/*.sh project/tests/
cp -a "$PIGEON_PROJECTS/$PROJECT_NAME"/build/. project/build/

mkfs.ext4 -q -F -d student student.img 16M
mkfs.ext4 -q -F -d project project.img 16M
mkfs.ext4 -q -F results.img 16M

cat >vm.json <<'EOF'
{
  "boot-source": {
    "kernel_image_path": "@kernel@",
    "boot_args": "reboot=k panic=1 init=/init quiet nomodule i8042.noaux i8042.nomux i8042.dumbkbd swiotlb=noforce console=ttyS0"
  },
  "drives": [
    { "drive_id": "rootfs",  "path_on_host": "@rootfs@",    "is_root_device": true,  "is_read_only": true },
    { "drive_id": "student", "path_on_host": "student.img", "is_root_device": false, "is_read_only": true },
    { "drive_id": "project", "path_on_host": "project.img", "is_root_device": false, "is_read_only": true },
    { "drive_id": "results", "path_on_host": "results.img", "is_root_device": false, "is_read_only": false }
  ],
  "machine-config": { "vcpu_count": 1, "mem_size_mib": 512 }
}
EOF

firecracker --no-api --level Error --config-file vm.json

RESULT=""
SCORE=0
TESTS="$PIGEON_PROJECTS/$PROJECT_NAME/tests"
for TEST in "$TESTS"/*.sh ; do
  debugfs -R "cat /$(basename "$TEST" .sh)" results.img >scratch 2>/dev/null
  if cmp -s scratch "$TESTS/$(basename "$TEST" .sh).expected" ; then
    RESULT="${RESULT}PASS\n"
    SCORE=$((SCORE + 1))
  else
    RESULT="${RESULT}FAIL: $(cat "$TESTS/$(basename "$TEST" .sh).hint")\n"
  fi
done

# Record before reporting, so a GitLab outage doesn't lose the result.
db "UPDATE results SET score = $SCORE WHERE id = $ROW;" ||
  echo "pigeon: failed to record score for row $ROW in $PIGEON_DB" >&2

report "$RESULT"