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

MAX_LOC="${MAX_LOC:-500}"
ROOT_DIR="$(git rev-parse --show-toplevel 2>/dev/null || pwd)"
EXCEPTIONS_FILE="${ROOT_DIR}/.claude/rules/loc-exceptions.txt"

red()   { printf '\033[31m%s\033[0m\n' "$*"; }
green() { printf '\033[32m%s\033[0m\n' "$*"; }

is_exempt() {
  local file="$1"
  [[ -f "$EXCEPTIONS_FILE" ]] || return 1
  while IFS= read -r line; do
    [[ -z "$line" ]] && continue
    [[ "$line" =~ ^# ]] && continue
    local pattern="${line%%|*}"
    pattern="$(echo "$pattern" | xargs)"
    if [[ -n "$pattern" ]] && [[ "$file" == $pattern ]]; then
      return 0
    fi
  done < "$EXCEPTIONS_FILE"
  return 1
}

count_loc() {
  [[ -f "$1" ]] && awk 'END { print NR }' "$1" || echo 0
}

collect_changed_files() {
  { git diff --name-only --cached; git diff --name-only; git ls-files --others --exclude-standard; } | awk 'NF' | sort -u
}

main() {
  local mode="changed"
  [[ "${1:-}" == "--changed" ]] && mode="changed"
  [[ "${1:-}" == "--all" ]] && mode="all"

  local files=()
  if [[ "$mode" == "changed" ]]; then
    IFS=$'\n' read -d '' -r -a files < <(collect_changed_files)
  else
    IFS=$'\n' read -d '' -r -a files < <(find "$ROOT_DIR" \( -name '*.py' -o -name '*.go' -o -name '*.ts' -o -name '*.tsx' \) -not -path '*/node_modules/*' -not -path '*/.next/*' -not -path '*/__pycache__/*' -not -path '*/venv/*')
  fi

  local failed=0
  local violations=0

  for file in "${files[@]}"; do
    [[ -f "$file" ]] || continue
    is_exempt "$file" && continue
    local loc
    loc="$(count_loc "$file")"
    if (( loc > MAX_LOC )); then
      red "VIOLATION: $file ($loc LOC > $MAX_LOC)"
      violations=$((violations + 1))
      failed=1
    fi
  done

  if (( failed )); then
    red ""
    red "$violations file(s) exceed ${MAX_LOC} LOC budget."
    exit 1
  fi

  green "LOC budget check passed."
}

main "$@"