var colors = [
  "#e6b8af", "#f4cccc", "#fce5cd", "#fff2cc", "#d9ead3",
  "#d0e0e3", "#c9daf8", "#cfe2f3", "#d9d2e9", "#ead1dc",
  "#dd7e6b", "#ea9999", "#f9cb9c", "#ffe599", "#b6d7a8",
  "#a2c4c9", "#a4c2f4", "#9fc5e8", "#b4a7d6", "#d5a6bd",
  "#cc4125", "#e06666", "#f6b26b", "#ffd966", "#93c47d",
  "#76a5af", "#6d9eeb", "#6fa8dc", "#8e7cc3", "#c27ba0"
];

var attentionColors = ['#00ffff', '#ff00ff', '#800080'];

function groupValues(values) {
  return values.reduce(function(acc, row, index) {
    var bid = Bid(row, index);
    if (bid.carName === '') {
      acc.push([]);
    } else {
      acc[acc.length - 1].push(bid);
    }
    return acc;
  }, [[]])
  .filter(function(row) {
    return row.length;
  })
  .map(function(group) {
    return Group(group);
  });
}

function Bid(row, index) {
  return {
    index: index,
    bidType: row[1],
    carName: row[2],
    yesNo: row[3],
    buyer: row[4].split(' ')[0] || '',
    bid: row[4].split(' ')[1] || null,
    wantsToBuy: +row[5],
    additional: row[6]
  };
}

function Group(bids) {
  return {
    buyer: bids[0].buyer,
    wantsToBuy: bids[0].wantsToBuy,
    bids: bids,
    hasActive: bids.some(function(bid) { return bid.bidType === '!'; })
  };
}

function colorRows(groups, sheet) {
  var groupColor = 0;

  groups.forEach(function(group) {
    if (group.wantsToBuy !== 0) {
      group.bids.forEach(function(row) {
        if (group.hasActive) {
          return;
        }
        var range = sheet.getRange(row.index + 1, 3);
        var isAttentionColor = (function() {
          var background = range.getBackground();

          return attentionColors.some(function(color) {
            return color === background;
          });
        })();


        if (isAttentionColor) {
          return;
        }

        range.setBackground('none');
        range.setBackground(colors[groupColor]);
      });
      groupColor = (groupColor + 1) % colors.length;
    }
  });
}

function highlight() {
  var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
  var sheets = spreadsheet.getSheets();
  sheets.forEach(function(sheet) {
    var dataRange = sheet.getDataRange();
    var values = dataRange.getValues();
    var groups = groupValues(values);
    colorRows(groups, sheet);
  });
}