#!/usr/bin/env bash
# check_the_checker for scripts/bd-audit-ids. A throwaway git repo and a fake
# bd; no network, no real tracker. See context/test-evidence/tooling.md.
set -uo pipefail

here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
AUDIT="$here/bd-audit-ids"
work="$(mktemp -d)"
trap 'rm -rf "$work"' EXIT

pass=0; fail=0
ok()  { printf '  ok   %s\n' "$1"; pass=$((pass+1)); }
bad() { printf '  FAIL %s (%s)\n' "$1" "$2"; fail=$((fail+1)); }

# The fake bd answers `list` from $FAKE_BD_OUT and exits $FAKE_BD_RC; any
# other subcommand is an error, so the audit cannot pass by calling `show`.
mkdir -p "$work/bin"
cat > "$work/bin/bd" <<'EOF'
#!/usr/bin/env bash
[ "${1:-}" = list ] || { echo "fake bd: unexpected '$*'" >&2; exit 2; }
[ -f "${FAKE_BD_OUT:-}" ] && cat "$FAKE_BD_OUT"
exit "${FAKE_BD_RC:-0}"
EOF
chmod +x "$work/bin/bd"

repo="$work/repo"
mkdir -p "$repo/context" "$repo/harness/serve"
git -C "$repo" init -q
printf 'serve/\n' > "$repo/harness/.gitignore"
# A live id, and a crate name the exclusion list must drop: without the
# exclusion, improvise-core would be reported dead and the first case fails.
printf 'See improvise-ab12 in improvise-core.\n' > "$repo/context/notes.md"
# Ignored build output with a dead id. The audit reads git's file list, so
# this must never be reported (improvise-8haj).
printf 'improvise-gone9\n' > "$repo/harness/serve/copy.md"

printf '[{"id":"improvise-ab12"},{"id":"improvise-cd34"}]\n' > "$work/known.json"
printf '' > "$work/empty"
printf '[]\n' > "$work/none.json"

# $1 name, $2 expected exit, $3 grep -E pattern the output must contain;
# the caller sets FAKE_BD_* and BD_AUDIT_BD in the environment.
run_case() {
  local name="$1" want="$2" pat="$3"
  (cd "$repo" && "$AUDIT") > "$work/out" 2>&1
  local got=$?
  if [ "$got" != "$want" ]; then bad "$name" "exit $got, wanted $want: $(head -c 200 "$work/out")"
  elif ! grep -Eq "$pat" "$work/out"; then bad "$name" "no /$pat/ in: $(head -c 200 "$work/out")"
  else ok "$name"; fi
}

export BD_AUDIT_BD="$work/bin/bd"

FAKE_BD_OUT="$work/known.json" FAKE_BD_RC=0 \
  run_case "every cited id known is a pass" 0 'all 1 cited ids resolve'

printf 'Also improvise-zzzq.\n' > "$repo/context/dead.md"
FAKE_BD_OUT="$work/known.json" FAKE_BD_RC=0 \
  run_case "a dead id is exit 1, and named" 1 '^  improvise-zzzq$'
rm -f "$repo/context/dead.md"

# The three shapes of "bd never answered". The recipe this replaced reported
# "all resolve" for every one of them (improvise-52eq).
FAKE_BD_OUT="$work/empty" FAKE_BD_RC=0 \
  run_case "a bd that prints nothing is not a pass" 3 'did not print a JSON list|returned no issues'
FAKE_BD_OUT="$work/none.json" FAKE_BD_RC=0 \
  run_case "a bd that lists no issues is not a pass" 3 'returned no issues'
FAKE_BD_OUT="$work/known.json" FAKE_BD_RC=1 \
  run_case "a bd that fails is not a pass" 3 'list. failed'
BD_AUDIT_BD="$work/bin/no-such-bd" \
  run_case "a missing bd is not a pass" 3 'is not on PATH'

# The live repo, with the fake bd listing nothing: if this passed, a real
# audit whose bd fell silent would pass too.
(cd "$here/.." && FAKE_BD_OUT="$work/none.json" "$AUDIT") > "$work/out" 2>&1
got=$?
[ "$got" = 3 ] && ok "the real tree does not pass against a silent bd" \
  || bad "the real tree does not pass against a silent bd" "exit $got"

# improvise-lqs0: a file the scan cannot read, and the two exit-code mismatches.
# A second repo, so the file list is exactly these cases' files.
r2="$work/repo2"
mkdir -p "$r2/context"
git -C "$r2" init -q
printf 'improvise-ab12\n' > "$r2/context/a.md"
printf 'improvise-dead9\n' > "$r2/context/b.md"
git -C "$r2" add -A
git -C "$r2" -c user.name=t -c user.email=t@t commit -qm fixture
export FAKE_BD_OUT="$work/known.json" FAKE_BD_RC=0

(cd "$r2" && "$AUDIT") > "$work/out" 2>&1
got=$?
[ "$got" = 1 ] && grep -q 'improvise-dead9' "$work/out" \
  && ok "control: both files readable, the dead id is found" \
  || bad "control: both files readable, the dead id is found" "exit $got"

# A symlink whose target is gone reads as an error for any user, root included.
ln -s missing-target "$r2/context/c.md"
(cd "$r2" && "$AUDIT") > "$work/out" 2>&1
got=$?
[ "$got" = 4 ] && ok "a cited file grep cannot read is exit 4, not a pass" \
  || bad "a cited file grep cannot read is exit 4, not a pass" "exit $got: $(head -c 200 "$work/out")"
rm -f "$r2/context/c.md"

if [ "$(id -u)" != 0 ]; then
  chmod 000 "$r2/context/b.md"
  (cd "$r2" && "$AUDIT") > "$work/out" 2>&1
  got=$?
  chmod 644 "$r2/context/b.md"
  [ "$got" = 4 ] && ok "an unreadable cited file is exit 4, not a pass" \
    || bad "an unreadable cited file is exit 4, not a pass" "exit $got: $(head -c 200 "$work/out")"
fi

# Decided, not accidental: a tracked file deleted from the working tree is not
# scanned. Its ids are leaving the tree, so its dead id is not reported.
mv "$r2/context/b.md" "$work/b.md.away"
(cd "$r2" && "$AUDIT") > "$work/out" 2>&1
got=$?
mv "$work/b.md.away" "$r2/context/b.md"
[ "$got" = 0 ] && ok "a tracked file deleted from the working tree is not scanned" \
  || bad "a tracked file deleted from the working tree is not scanned" "exit $got: $(head -c 200 "$work/out")"

# Absent is not deleted: a skip-worktree path is missing too, but ls-files -d
# does not list it, so its ids were never read (improvise-tdfd).
git -C "$r2" update-index --skip-worktree context/b.md
mv "$r2/context/b.md" "$work/b.md.away"
(cd "$r2" && "$AUDIT") > "$work/out" 2>&1
got=$?
mv "$work/b.md.away" "$r2/context/b.md"
git -C "$r2" update-index --no-skip-worktree context/b.md
[ "$got" = 4 ] && grep -q 'context/b.md' "$work/out" \
  && ok "a skip-worktree file missing from the tree is exit 4, and named" \
  || bad "a skip-worktree file missing from the tree is exit 4, and named" "exit $got: $(head -c 200 "$work/out")"

# ls-files -d DOES list an absent assume-unchanged path, yet status hides it and
# commit -a never records the deletion (improvise-cota).
git -C "$r2" update-index --assume-unchanged context/b.md
mv "$r2/context/b.md" "$work/b.md.away"
(cd "$r2" && "$AUDIT") > "$work/out" 2>&1
got=$?
mv "$work/b.md.away" "$r2/context/b.md"
git -C "$r2" update-index --no-assume-unchanged context/b.md
[ "$got" = 4 ] && grep -q 'context/b.md' "$work/out" \
  && ok "an assume-unchanged file missing from the tree is exit 4, and named" \
  || bad "an assume-unchanged file missing from the tree is exit 4, and named" "exit $got: $(head -c 200 "$work/out")"

mkdir -p "$work/not-a-repo"
(cd "$work/not-a-repo" && GIT_CEILING_DIRECTORIES="$work" "$AUDIT") > "$work/out" 2>&1
got=$?
[ "$got" = 4 ] && ok "run outside a git repository is exit 4" \
  || bad "run outside a git repository is exit 4" "exit $got"

printf '[{"title":"no id here"}]\n' > "$work/noid.json"
FAKE_BD_OUT="$work/noid.json" \
  run_case "a bd listing issues with no id is exit 3, not every id dead" 3 'did not print'
unset FAKE_BD_OUT FAKE_BD_RC

"$AUDIT" --help > "$work/out" 2>&1
got=$?
[ "$got" = 4 ] && grep -q 'POSITIVE' "$work/out" \
  && ok "--help is exit 4 and states the positive comparison" \
  || bad "--help is exit 4 and states the positive comparison" "exit $got"

printf '\nbd-audit-ids-test: %d passed, %d failed\n' "$pass" "$fail"
[ "$fail" -eq 0 ]