#!/usr/bin/env bash
# Regression harness for lane-brief.sh PR->issue linkage classification.
#
# Covers the #546/#547 defect: lane-brief.sh inspected only the PR index/title/head
# fields and never the PR BODY, so an open PR whose body says "Closes #546" did not
# mark issue #546 as work-underway — #546 was listed as a DISPATCH CANDIDATE and was
# re-dispatchable in-flight work.
#
# Asserts:
#   1. an open issue closed-keyword-linked from a PR BODY ("Closes #546") is
#      classified WORK UNDERWAY, not a dispatch candidate.
#   2. a BARE "#777" prose mention in a PR body does NOT classify #777 as
#      work-underway (only Gitea closing keywords are a real link) — #777 stays a
#      dispatch candidate.
#   3. NON-VACUITY / RED-ON-REVERT: a copy of the script with the body-scan removed
#      misclassifies #546 as a dispatch candidate — proving the body-scan is exactly
#      what fixes the defect and that assertion 1 fails if the fix is reverted.

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
LANE_BRIEF="$SCRIPT_DIR/lane-brief.sh"
WORK_DIR="${MOSAIC_TEST_WORK_DIR:-$PWD/.mosaic-test-work/lane-brief-pr-linkage}"
BIN_DIR="$WORK_DIR/bin"

rm -rf "$WORK_DIR"
mkdir -p "$BIN_DIR"

# --- fake `tea`: serves a fixed open-issue set and one open PR. ----------------
# PR #547 body uses a closing keyword for #546 ("Closes #546") and a BARE mention
# of #777 ("the #777 line of work"). #777 must NOT be treated as linked.
cat > "$BIN_DIR/tea" <<'SH'
#!/usr/bin/env bash
set -euo pipefail
case "${1:-} ${2:-}" in
  "issues list")
    cat <<'JSON'
[
  {"index":"546","title":"lane-brief + ci-wait orchestration tooling","assignees":[],"milestone":null,"labels":""},
  {"index":"777","title":"unrelated downstream item","assignees":[],"milestone":null,"labels":""},
  {"index":"999","title":"item only named inside the word hotfix","assignees":[],"milestone":null,"labels":""}
]
JSON
    ;;
  "pulls list")
    cat <<'JSON'
[
  {"index":"547","title":"feat(framework/tools): orchestration helpers","head":"feat/orchestration-tools-lane-brief-ci-wait","body":"Two additive orchestration tools.\n\nCloses #546.\n\nLogin resolution is relevant to the #777 line of work but does not touch it.\nThis shipped as a hotfix #999 earlier — that bare reference must not link it.\n\nFixes #546\n"}
]
JSON
    ;;
  *)
    echo "fake-tea: unhandled: $*" >&2; exit 1 ;;
esac
SH
chmod +x "$BIN_DIR/tea"

run_brief() { # $1 = script path
  PATH="$BIN_DIR:$PATH" "$1" -r mosaic/stack -L test-login 2>/dev/null
}

# Extract the issue numbers under a named section header until the next blank line.
section_nums() { # $1 = output  $2 = header-prefix
  printf '%s\n' "$1" | awk -v h="$2" '
    index($0,h)==1 {grab=1; next}
    grab && /^[[:space:]]*$/ {grab=0}
    grab && match($0, /#[0-9]+/) { print substr($0, RSTART+1, RLENGTH-1) }
  '
}

fail() { echo "FAIL: $1" >&2; exit 1; }
contains() { printf '%s\n' "$1" | grep -qx "$2"; }

# ---------------------------------------------------------------------------
# Fixed (current) script behavior
# ---------------------------------------------------------------------------
OUT="$(run_brief "$LANE_BRIEF")"
CAND="$(section_nums "$OUT" 'DISPATCH CANDIDATES')"
UNDER="$(section_nums "$OUT" 'WORK UNDERWAY')"

echo "--- lane-brief output (fixed) ---"; printf '%s\n' "$OUT"
echo "--- candidates: [$(printf '%s' "$CAND" | tr '\n' ' ')] underway: [$(printf '%s' "$UNDER" | tr '\n' ' ')] ---"

contains "$UNDER" 546 || fail "#546 (PR body 'Closes #546') should be WORK UNDERWAY"
contains "$CAND" 546 && fail "#546 must NOT be a dispatch candidate (it has an open PR)"
contains "$CAND" 777 || fail "#777 (only a bare prose mention) should remain a dispatch candidate"
contains "$UNDER" 777 && fail "#777 must NOT be work-underway — bare body mentions are not links"
contains "$CAND" 999 || fail "#999 ('hotfix #999' — keyword is a substring) should remain a candidate"
contains "$UNDER" 999 && fail "#999 must NOT be work-underway — word-boundary must reject 'hotfix'"
echo "PASS: body closing-keyword link classifies #546 underway; bare #777 / substring #999 stay candidates"

# ---------------------------------------------------------------------------
# NON-VACUITY: revert the body-scan and prove #546 regresses to a candidate.
# ---------------------------------------------------------------------------
REVERTED="$SCRIPT_DIR/.lane-brief.reverted.$$.sh"
trap 'rm -f "$REVERTED"' EXIT
# Drop the PR_BODY_REFS contribution from the union (simulates the pre-fix script
# that only looked at index/title/head). Sibling `source detect-platform.sh` still
# resolves because the copy lives in the same dir.
# shellcheck disable=SC2016  # single-quoted on purpose: sed needs the literal $PR_BODY_REFS
sed 's/"\$PR_BODY_REFS"/""/' "$LANE_BRIEF" > "$REVERTED"
chmod +x "$REVERTED"
grep -q 'PR_BODY_REFS' "$REVERTED" || fail "revert sed anchor not found — test is stale"

ROUT="$(run_brief "$REVERTED")"
RCAND="$(section_nums "$ROUT" 'DISPATCH CANDIDATES')"
RUNDER="$(section_nums "$ROUT" 'WORK UNDERWAY')"
echo "--- candidates(reverted): [$(printf '%s' "$RCAND" | tr '\n' ' ')] underway: [$(printf '%s' "$RUNDER" | tr '\n' ' ')] ---"

contains "$RCAND" 546 || fail "non-vacuity broken: reverted script should misclassify #546 as a candidate"
contains "$RUNDER" 546 && fail "non-vacuity broken: reverted script should NOT mark #546 underway"
echo "PASS (RED-on-revert): without the body-scan, #546 regresses to a dispatch candidate"

echo "ALL PASS: test-lane-brief-pr-linkage.sh"
