#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "$ROOT_DIR"

log() {
  printf '[check-feature-spec] %s\n' "$1"
}

BASE_SHA="${BASE_SHA:-}"
if [[ -z "$BASE_SHA" ]]; then
  if git rev-parse --verify origin/main >/dev/null 2>&1; then
    BASE_SHA="$(git merge-base origin/main HEAD)"
  else
    log "No BASE_SHA and origin/main unavailable; skipping check."
    exit 0
  fi
fi

if ! git rev-parse --verify "$BASE_SHA" >/dev/null 2>&1; then
  log "BASE_SHA '$BASE_SHA' not found; skipping check."
  exit 0
fi

changed_files="$(git diff --name-only "$BASE_SHA"...HEAD)"
if [[ -z "$changed_files" ]]; then
  log "No changed files; nothing to enforce."
  exit 0
fi

code_changed=0
spec_changed=0

while IFS= read -r path; do
  [[ -z "$path" ]] && continue

  case "$path" in
    frontend/src/*|backend/*|src-tauri/src/*|shared/project-schema.json)
      code_changed=1
      ;;
  esac

  case "$path" in
    docs/specs/*.md)
      spec_changed=1
      ;;
  esac
done <<< "$changed_files"

if [[ "$code_changed" -eq 0 ]]; then
  log "No app code changes detected; spec file not required."
  exit 0
fi

if [[ "$spec_changed" -eq 1 ]]; then
  log "Spec requirement satisfied."
  exit 0
fi

log "Code changes detected without spec update in docs/specs/."
log "Add or update at least one spec file using docs/spec-template.md."
exit 1