#!/usr/bin/env bash
# validate-sdd.sh
# Ensures changed spec folders keep mandatory SDD artifacts.
set -euo pipefail

BASE_REF="${1:-origin/main}"

if ! git rev-parse --verify "$BASE_REF" >/dev/null 2>&1; then
  BASE_REF="HEAD~1"
fi

CHANGED_SPEC_FILES=()
while IFS= read -r line; do
  [[ -n "$line" ]] && CHANGED_SPEC_FILES+=("$line")
done < <(git diff --name-only "$BASE_REF"...HEAD -- 'specs/**')

if [[ ${#CHANGED_SPEC_FILES[@]} -eq 0 ]]; then
  echo "[validate-sdd] No changes under specs/."
  exit 0
fi

SPEC_DIRS=()
add_unique_dir() {
  local candidate="$1"
  local existing
  for existing in "${SPEC_DIRS[@]:-}"; do
    [[ "$existing" == "$candidate" ]] && return 0
  done
  SPEC_DIRS+=("$candidate")
}

for path in "${CHANGED_SPEC_FILES[@]}"; do
  if [[ "$path" =~ ^specs/[^/]+/ ]]; then
    spec_dir="$(echo "$path" | cut -d/ -f1-2)"
    add_unique_dir "$spec_dir"
  fi
done

if [[ ${#SPEC_DIRS[@]} -eq 0 ]]; then
  echo "[validate-sdd] PASS (no feature spec directories changed)"
  exit 0
fi

FAILED=0
for dir in "${SPEC_DIRS[@]}"; do
  for required in spec.md plan.md tasks.md allowed-files.txt; do
    if [[ ! -f "$dir/$required" ]]; then
      echo "[validate-sdd] Missing required file: $dir/$required"
      FAILED=1
    fi
  done
done

if [[ $FAILED -ne 0 ]]; then
  exit 1
fi

echo "[validate-sdd] PASS ($BASE_REF...HEAD)"