#!/usr/bin/env bash
# Husky commit-msg hook — runs commitlint + skill-invocation sentinel check.
#
# 1. Runs commitlint to validate commit message format (Conventional Commits,
#    SDLC trailers).
# 2. If the commit is feat/fix/refactor/perf, checks for the
#    .sdlc-implementer-invoked sentinel. If missing, blocks the commit —
#    the sdlc-implementer skill was not invoked (devaudit-installer#199/#226).
#    Housekeeping types (docs/chore/ci/build/test/revert) are exempt.
# 3. If the commit is an exempt type but its staged files fall under
#    sdlc-config.json's source_dirs (application code), warns — does not
#    block — since an exempt type is a self-declared label with no check
#    against the actual diff otherwise (devaudit-installer#768).
#
# Bypass with --no-verify (last resort — pre-push hook and CI also check).
#
# Install: cp this file to .husky/commit-msg && chmod +x .husky/commit-msg

COMMIT_MSG_FILE="$1"

# ── 1. Commitlint ────────────────────────────────────────────────────
npx commitlint --edit "$COMMIT_MSG_FILE"

# ── 2. Skill-invocation sentinel (devaudit-installer#199/#226) ──────
# If the commit type is feat/fix/refactor/perf, verify the
# sdlc-implementer skill was invoked (writes .sdlc-implementer-invoked).
# Housekeeping types are exempt. This fires at commit time — earlier
# than the pre-push hook — so the agent hits the gate before it can
# even create the commit.
TRACKED_TYPES='^(feat|fix|refactor|perf)(\(.+\))?!?:'
COMMIT_SUBJECT=$(head -1 "$COMMIT_MSG_FILE")

if echo "$COMMIT_SUBJECT" | grep -qE "$TRACKED_TYPES"; then
  if [ ! -f .sdlc-implementer-invoked ]; then
    echo ""
    echo "ERROR: sdlc-implementer skill was not invoked (devaudit-installer#199)."
    echo "       This commit uses a tracked type ($COMMIT_SUBJECT) which requires"
    echo "       the SDLC skill flow. The .sdlc-implementer-invoked sentinel is missing."
    echo ""
    echo "       Invoke sdlc-implementer to drive the process, or use --no-verify"
    echo "       to bypass (not recommended — pre-push hook and CI will also check)."
    exit 1
  fi
fi

# ── 3. Diff-shape heuristic for exempt-typed commits (devaudit-installer#768) ──
# An exempt type (docs/chore/ci/build/test/revert/compliance) is a
# self-declared label with no check against the staged diff — nothing
# stops real feature/bug/refactor work labeled this way from bypassing
# the sentinel check above entirely. Warns (doesn't block) when an
# exempt-typed commit's staged files fall under sdlc-config.json's
# source_dirs (application code, not tooling/docs/config) — a real
# housekeeping change can legitimately touch source_dirs (a config
# constant, say), so this is visibility, not a gate.
EXEMPT_TYPES='^(docs|chore|ci|build|test|revert|compliance)(\(.+\))?!?:'
if echo "$COMMIT_SUBJECT" | grep -qE "$EXEMPT_TYPES" && [ -f sdlc-config.json ]; then
  SOURCE_DIRS=$(jq -r '.source_dirs // empty' sdlc-config.json 2>/dev/null || true)
  if [ -n "$SOURCE_DIRS" ]; then
    STAGED_FILES=$(git diff --cached --name-only 2>/dev/null || true)
    FLAGGED=""
    for dir in $SOURCE_DIRS; do
      MATCHES=$(echo "$STAGED_FILES" | grep -E "^${dir}" || true)
      if [ -n "$MATCHES" ]; then
        FLAGGED="${FLAGGED}${MATCHES}"$'\n'
      fi
    done
    if [ -n "$FLAGGED" ]; then
      echo ""
      echo "WARNING: commit typed as exempt ($COMMIT_SUBJECT) touches configured"
      echo "         source_dirs (application code), not just tooling/docs/config:"
      echo "$FLAGGED" | sed 's/^/           /'
      echo ""
      echo "         If this is real feature/bug/refactor work, use a tracked commit"
      echo "         type and invoke sdlc-implementer instead (devaudit-installer#768)."
      echo "         Proceeding — this is a warning, not a block."
      echo ""
    fi
  fi
fi