const _ = require('lodash')
const moment = require('moment-immutable')
const { getWeeks, formatDate, parseDate } = require('../dates')
const { StaffMember, Workday, Terminal, Labor, sequelize } = require('../database')
const { Op } = require('sequelize')
const overtime = require('../overtime')

const list = async (req, res) => {
  const terminalKey = req.params.terminal
  const terminal = await Terminal.findOne({where: {key: terminalKey}})
  if (!terminal) return res.status(404).end()
  const workdays = await Workday.findAll({where: { terminalId: terminal.id }})

  let workweeks = _.groupBy(workdays, d => formatDate(moment(d.date).startOf('week')))

  // fill workweeks
  getWeeks(10).forEach(week => {
    const w = formatDate(week)
    if (!workweeks[w]) workweeks[w] = []
  })

  // fill workdays
  workweeks = _.chain(workweeks)
    .toPairs()
    .map(([w, days]) => {
      days  = _.chain(days)
        .map(d => [moment(d.date).weekday(), d])
        .fromPairs()
        .value()
      
      days = _.range(0, 7).map(d => days[d] || null)
        .map(day => day && {
          hours: day.hours,
          laborCost: day.laborCost
        })

      return {
        workweek: w,
        workdays: days
      }
    })
    .sortBy(x => x.workweek)
    .reverse()
    .value()

  res.status(200).send(workweeks)
}

const get = async (req, res) => {
  const terminalKey = req.params.terminal
  const terminal = await Terminal.findOne({where: {key: terminalKey}})
  const week = parseDate(req.params.week)
  const workdays = await Workday.findAll({
    where: {
      terminalId: terminal.id,
      date: {
        [Op.gte]: week,
        [Op.lte]: moment(week).endOf('week')
      }
    },
    order: [ 'date' ]
  })
  const labor = await Labor.findAll({
    where: {
      workdayId: {
        [Op.in]: workdays.map(x => x.id)
      }
    }
  })
  const laborByWorkday = _.groupBy(labor, x => x.workdayId)
  const extraStaffMembers = _.chain(labor)
    .map(x => x.staffMemberId)
    .filter(x => x)
    .uniq()
    .value()
  const staffMembers = await StaffMember.findAll({
    where: {
      [Op.or]: [
        { terminalId: terminal.id },
        {
          id: {
            [Op.in]: extraStaffMembers
          }
        }
      ]      
    },
    order: [ 'name' ]
  })
  const staffMembersById = _.chain(staffMembers).map(x => [x.id, x]).fromPairs().value()

  // Fill in empty days
  const workdaysByKey = _.chain(workdays).map(wd => [formatDate(wd.date), wd]).fromPairs().value()
  const allWorkdays = []
  for (let day = week, i = 0; i < 7; i++, day = day.add(1, 'day')) {
    const wd = workdaysByKey[formatDate(day)]
    allWorkdays[i] = wd ? wd.toJSON() : {}
  }

  const workdaysWithLabor = allWorkdays.map(wd => {
    const labor = laborByWorkday[wd.id] || []
    const laborByStaffMember = _.chain(labor).map(l => [l.staffMemberId, l]).fromPairs().value()
    // Map from staffMembers to preserve sorting
    wd.labor = staffMembers
      .map(sm => laborByStaffMember[sm.id] || {staffMemberId: sm.id})
      .map(sm => ({
        staffMemberId: sm.staffMemberId,
        hours: sm.hours
      }))
    // Restore any staffMembers that are no longer assigned this terminal
    labor.forEach(l => {
      if (!staffMembersById[l.staffMemberId]) {
        wd.labor.push(l)
      }
    })
    return wd
  })

  res.status(200).send({
    workdays: allWorkdays
  })
}

const patch = async (req, res) => {
  const transaction = await sequelize.transaction()
  try {
    const terminalKey = req.params.terminal
    const terminal = await Terminal.findOne({where: {key: terminalKey}})
    const week = parseDate(req.params.week)
    const workdays = await Workday.findAll({
      where: {
        terminalId: terminal.id,
        date: {
          [Op.gte]: week,
          [Op.lt]: moment(week).endOf('week')
        }
      },
      order: [ 'date' ]
    })
    const labor = await Labor.findAll({
      where: {
        workdayId: {
          [Op.in]: workdays.map(x => x.id)
        }
      }
    })
    const laborByWorkday = _.groupBy(labor, x => x.workdayId)
    const extraStaffMembers = _.chain(labor)
      .map(x => x.staffMemberId)
      .filter(x => x)
      .uniq()
      .value()
    const staffMembers = await StaffMember.findAll({
      where: {
        [Op.or]: [
          { terminalId: terminal.id },
          {
            id: {
              [Op.in]: extraStaffMembers
            }
          }
        ]      
      },
      order: [ 'name' ]
    })
    const staffMembersById = _.chain(staffMembers).map(x => [x.id, x]).fromPairs().value()

    // Fill in empty days
    const workdaysByKey = _.chain(workdays).map(wd => [formatDate(wd.date), wd]).fromPairs().value()
    const allWorkdays = []
    for (let day = week, i = 0; i < 7; i++, day = day.add(1, 'day')) {
      const wd = workdaysByKey[formatDate(day)]
      allWorkdays[i] = wd || Workday.build({
        terminalId: terminal.id,
        date: week.add(i, 'day')
      })
    }

    const workdaysWithLabor = allWorkdays.map(wd => {
      const labor = laborByWorkday[wd.id] || []
      const laborByStaffMember = _.chain(labor).map(l => [l.staffMemberId, l]).fromPairs().value()
      // Map from staffMembers to preserve sorting
      wd.labor = staffMembers.map(sm => laborByStaffMember[sm.id] || Labor.build({staffMemberId: sm.id, workdayId: wd.id}))
      // Restore any staffMembers that are no longer assigned this terminal
      labor.forEach(l => {
        if (!staffMembersById[l.staffMemberId]) {
          wd.labor.push(l)
        }
      })
      return wd
    })

    // Update with model
    const model = req.body
    await Promise.all(model.workdays.map(async (modelWorkday, i) => {
      const modelLaborById = _.chain(modelWorkday.labor).map(l => [l.staffMemberId, l]).fromPairs().value()
      const workday = allWorkdays[i]
      workday.labor.forEach(labor => {
        const modelLabor = modelLaborById[labor.staffMemberId]
        const staffMember = staffMembersById[labor.staffMemberId]
        const priorHours = model.workdays
          .slice(0, i)
          .map(wd => wd.labor.find(l => l.staffMemberId === labor.staffMemberId).hours)
          .reduce((a, b) => a + b, 0)
        const hours = overtime(modelLabor.hours || 0, priorHours, terminalKey)
        labor.hours = modelLabor.hours || 0
        labor.regularHours = hours.regularHours
        labor.overtimeHours = hours.overtimeHours
        labor.doubletimeHours = hours.doubletimeHours
        labor.laborCost = 
          (staffMember.wage * labor.regularHours || 0) +
          (staffMember.wage * labor.overtimeHours * 1.5 || 0) +
          (staffMember.wage * labor.doubletimeHours * 2.0 || 0) +
          (staffMember.salary / 2080 * labor.hours || 0)
      })
      workday.hours = workday.labor.map(l => l.hours || 0).reduce((a, b) => a + b, 0)
      workday.regularHours = workday.labor.map(l => l.regularHours || 0).reduce((a, b) => a + b, 0)
      workday.overtimeHours = workday.labor.map(l => l.overtimeHours || 0).reduce((a, b) => a + b, 0)
      workday.doubletimeHours = workday.labor.map(l => l.doubletimeHours || 0).reduce((a, b) => a + b, 0)
      workday.laborCost = workday.labor.map(l => l.laborCost || 0).reduce((a, b) => a + b, 0)

      if (workday.hours || !workday.isNewRecord) {
        await workday.save({ transaction })
      }

      await Promise.all(workday.labor.map(async labor => {
        if (labor.hours || !labor.isNewRecord) {
          await labor.save({ transaction })
        }
      }))

    }))


    await transaction.commit()
    
    res.status(200).end()

  } catch (err) {
    await transaction.rollback()
    throw err
  }
}
module.exports = {
  list,
  get,
  patch
}