#include "TerminalSearch.h"

QVector<SearchMatch> findAllMatches(const QVector<SearchRow>& rows,
                                    const QString& query) {
  QVector<SearchMatch> matches;
  const QString needle = query.trimmed();
  if (needle.isEmpty()) {
    return matches;
  }
  const qsizetype needleLen = needle.length();
  for (const SearchRow& row : rows) {
    if (row.text.isEmpty()) {
      continue;
    }
    // Case-insensitive plain substring scan. from advances past each hit so
    // overlapping occurrences are all reported left to right.
    qsizetype from = 0;
    while (true) {
      const qsizetype hit =
          row.text.indexOf(needle, from, Qt::CaseInsensitive);
      if (hit < 0) {
        break;
      }
      // UTF-16 offset -> cell column. columnOfChar (when populated) maps
      // every unit to its grid column, so wide graphemes keep the span
      // honest; without it the offset IS the column.
      const int startCol =
          row.columnOfChar.isEmpty()
              ? static_cast<int>(hit)
              : row.columnOfChar[static_cast<int>(hit)];
      const qsizetype lastUnit = hit + needleLen - 1;
      const int endColIncl =
          row.columnOfChar.isEmpty()
              ? static_cast<int>(lastUnit)
              : row.columnOfChar[static_cast<int>(lastUnit)];
      matches.append(SearchMatch{.row = row.row,
                                 .startCol = startCol,
                                 .endCol = endColIncl});
      from = hit + 1;
    }
  }
  return matches;
}

int wrapStepMatch(int current, int delta, int count) {
  if (count <= 0) {
    return -1;
  }
  if (current < 0 || current >= count) {
    // No valid selection: step in lands on the first (next) or last
    // (previous) match.
    return delta >= 0 ? 0 : count - 1;
  }
  const int next = current + delta;
  if (next < 0) {
    return count - 1;
  }
  if (next >= count) {
    return 0;
  }
  return next;
}