// Shared helpers for parsing and sorting web list query state.

function parsePageNumber(value) {
  const pageNumber = Math.floor(Number(value) || 1);
  return Math.max(1, pageNumber);
}

function getSearchQuery(req) {
  return String(req && req.query && req.query.search || '').trim();
}

function getSortQuery(req) {
  return String(req && req.query && req.query.sort || '').trim();
}

function getSortDirectionQuery(req) {
  return String(req && req.query && req.query.direction || '').trim().toLowerCase() === 'desc' ? 'desc' : 'asc';
}

function normalizeSortDirection(value) {
  return String(value || '').trim().toLowerCase() === 'desc' ? 'desc' : 'asc';
}

function getComparableSortValue(rawValue) {
  const value = String(rawValue || '').trim();
  if (!value) {
    return { type: 'empty', value: '' };
  }

  const numericValue = Number(value.replace(/,/g, ''));
  if (!Number.isNaN(numericValue)) {
    return { type: 'number', value: numericValue };
  }

  const dateValue = Date.parse(value);
  if (!Number.isNaN(dateValue)) {
    return { type: 'date', value: dateValue };
  }

  return { type: 'string', value: value.toLowerCase() };
}

function compareSortValues(leftValue, rightValue) {
  if (leftValue.type === 'empty' && rightValue.type === 'empty') {
    return 0;
  }
  if (leftValue.type === 'empty') {
    return 1;
  }
  if (rightValue.type === 'empty') {
    return -1;
  }
  if (leftValue.type === rightValue.type) {
    if (leftValue.value < rightValue.value) {
      return -1;
    }
    if (leftValue.value > rightValue.value) {
      return 1;
    }
    return 0;
  }
  return String(leftValue.value).localeCompare(String(rightValue.value), undefined, { numeric: true, sensitivity: 'base' });
}

function sortRows(rows, accessor, sortDirection) {
  const multiplier = normalizeSortDirection(sortDirection) === 'desc' ? -1 : 1;
  return (Array.isArray(rows) ? rows.slice() : []).sort(function (leftRow, rightRow) {
    return compareSortValues(getComparableSortValue(accessor(leftRow)), getComparableSortValue(accessor(rightRow))) * multiplier;
  });
}

function createSearchMatcher(searchTerm, fields) {
  const query = String(searchTerm || '').trim().toLowerCase();

  if (!query) {
    return function () {
      return true;
    };
  }

  const normalizedFields = Array.isArray(fields) ? fields : [];
  return function (item) {
    const haystack = normalizedFields.map(function (field) {
      if (typeof field === 'function') {
        return field(item);
      }
      return item && field ? item[field] : '';
    }).map(function (value) {
      return String(value || '').trim().toLowerCase();
    }).join(' ');

    return haystack.indexOf(query) !== -1;
  };
}

module.exports = {
  parsePageNumber: parsePageNumber,
  getSearchQuery: getSearchQuery,
  getSortQuery: getSortQuery,
  normalizeSortDirection: normalizeSortDirection,
  getSortDirectionQuery: getSortDirectionQuery,
  getComparableSortValue: getComparableSortValue,
  compareSortValues: compareSortValues,
  sortRows: sortRows,
  createSearchMatcher: createSearchMatcher
};