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

lcov_path="${1:-}"
if [[ -z "${lcov_path}" || ! -f "${lcov_path}" ]]; then
  echo "usage: $0 <path/to/file.lcov>" >&2
  exit 2
fi

# lcov format includes per-file LF (lines found) and LH (lines hit). Sum those.
awk '
  /^LF:/ { lf += substr($0, 4) }
  /^LH:/ { lh += substr($0, 4) }
  END {
    if (lf == 0) {
      printf("lines: 0/0 (0.00%%)\n")
      exit 0
    }
    pct = (lh * 100.0) / lf
    printf("lines: %d/%d (%.2f%%)\n", lh, lf, pct)
  }
' "${lcov_path}"