tw-shift-schedule/lib/overwork.js

班表小幫手

'use strict';

var lexer = require('./lexer');

var Causes = {
  irregular: '不規律的工作',
  longHours: '長時間工作',
  nightShift: '夜班',
  previousDayOverwork: '前一天長時間工作',
  previousWeekOverwork: '前一週長時間工作',
  previousMonthOvertime: '前一個月加班時數 > 100',
  previousSixMonthsOvertime: '前六個月加班時數平均 > 45'
};

module.exports = { Causes: Causes, check: check

  // 過勞定義 http://www.mqjh.tp.edu.tw/mediafile/1901/news/19/2016-1/22016-1-24-21-27-24-nf1.pdf
};function check(schedule) {
  var causes = [];
  // 只取出工作時段
  var tokens = prettify(schedule.header.start, lexer(schedule.body)).filter(function (t) {
    return t.type === 'work';
  });
  // 是否不規律

  // 假設：如果每班的開始時間跟結束時間都不在同個小時內就當作不規律
  var shiftStart;
  var shiftEnd;
  var t;
  var _iteratorNormalCompletion = true;
  var _didIteratorError = false;
  var _iteratorError = undefined;

  try {
    for (var _iterator = tokens[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
      t = _step.value;

      if (!shiftStart) {
        shiftStart = t.time;
        shiftEnd = shiftStart.clone().add(t.length, 'minutes');
        continue;
      }

      if (shiftStart.hour() !== t.time.hour() && shiftEnd.hour() !== t.time.hour()) {
        causes.push(Causes.irregular);
        break;
      }
    }

    // 長時間
    // 假設平均工時大於 8 小時就是長時間
  } catch (err) {
    _didIteratorError = true;
    _iteratorError = err;
  } finally {
    try {
      if (!_iteratorNormalCompletion && _iterator.return) {
        _iterator.return();
      }
    } finally {
      if (_didIteratorError) {
        throw _iteratorError;
      }
    }
  }

  var avgLength = tokens.map(function (t) {
    return t.length;
  }).reduce(function (sum, x) {
    return sum + x;
  }, 0) / 60 / tokens.length;
  if (avgLength > 8) {
    causes.push(Causes.longHours);
  }

  // 夜班
  // 下午 10 點 ~ 早上 6 點 = 夜班
  var _iteratorNormalCompletion2 = true;
  var _didIteratorError2 = false;
  var _iteratorError2 = undefined;

  try {
    for (var _iterator2 = tokens[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) {
      t = _step2.value;

      var startHour = t.time.hour();
      var endHour = t.time.clone().add(t.length, 'minutes').hour();
      if (startHour >= 22 || startHour <= 6 || endHour >= 22 || endHour <= 6) {
        causes.push(Causes.nightShift);
        break;
      }
    }

    // 短期工作過重
    // 前一日
    // 前一日是否比平均工時還長？
  } catch (err) {
    _didIteratorError2 = true;
    _iteratorError2 = err;
  } finally {
    try {
      if (!_iteratorNormalCompletion2 && _iterator2.return) {
        _iterator2.return();
      }
    } finally {
      if (_didIteratorError2) {
        throw _iteratorError2;
      }
    }
  }

  if (tokens[tokens.length - 1].length / 60 > avgLength) {
    causes.push(Causes.previousDayOverwork);
  }
  // 前一週
  // 前一週是否比平均工時還長？
  if (tokens.length >= 7 && lastAvgLenthInHour(tokens, 7) > avgLength) {
    causes.push(Causes.previousWeekOverwork);
  }

  // 長期工作過重
  // 加班時數
  // 加班時數定義：每週 40 小時之外的工時
  // 前一個月加班超過 100 小時
  if (tokens.length >= 30 && sumLastLengthInHour(tokens, 30) - 40 * 4 > 100) causes.push(Causes.previousMonthOvertime);

  // 前一至六個月平均加班超過 45 小時
  if (tokens.length >= 180 && sumLastLengthInHour(tokens, 180) / 6 - 40 * 4 > 45) causes.push(Causes.previousSixMonthsOvertime);

  return causes;
}

function lastAvgLenthInHour(tokens, length) {
  return sumLastLengthInHour(tokens, length) / length;
}

function sumLastLengthInHour(tokens, length) {
  var l = 0;
  for (var i = tokens.length - 1; i > tokens.length - 1 - length; i--) {
    l += tokens[i].length;
  }
  return l / 60;
}

function prettify(startTime, tokens) {
  return tokens.map(function (t) {
    return { type: t.type, length: t.value.length, line: t.line, time: offset2time(startTime, t.offset) };
  });
}

function offset2time(startTime, offset) {
  return startTime.clone().add(offset, 'minutes');
}