/*
Copyright (C) 2017  Cloudbase Solutions SRL
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

// @flow

import React from 'react'
import ReactDOM from 'react-dom'
import { observer } from 'mobx-react'
import styled, { injectGlobal } from 'styled-components'
import Datetime from 'react-datetime'
import moment from 'moment'

import DropdownButton from '../../atoms/DropdownButton'

import DomUtils from '../../../utils/DomUtils'
import DateUtils from '../../../utils/DateUtils'
import StyleProps from '../../styleUtils/StyleProps'

import style from './style.js'

require('moment/locale/en-gb')

injectGlobal`${style}`

const Wrapper = styled.div`
  width: ${StyleProps.inputSizes.regular.width}px;
`
const DropdownButtonStyled = styled(DropdownButton)`
  font-size: 12px;
`
const Portal = styled.div`
  position: absolute;
  z-index: 10;
  &.hideTip {
    .rdtPicker:after {
      content: none;
    }
  }
`
const DatetimeStyled = styled(Datetime)``

type Props = {
  value: ?Date,
  onChange: (date: Date) => void,
  isValidDate?: (currentDate: Date, selectedDate: Date) => boolean,
  timezone: 'utc' | 'local',
  useBold?: boolean,
}
type State = {
  showPicker: boolean,
  date: ?moment$Moment,
}
@observer
class DatetimePicker extends React.Component<Props, State> {
  itemMouseDown: boolean
  portalRef: HTMLElement
  buttonRef: HTMLElement
  scrollableParent: HTMLElement

  constructor() {
    super()

    this.state = {
      showPicker: false,
      date: null,
    }

    // $FlowIssue
    this.handlePageClick = this.handlePageClick.bind(this)

    // $FlowIssue
    this.handleScroll = this.handleScroll.bind(this)
  }

  componentWillMount() {
    if (this.props.value) {
      this.setState({ date: moment(this.props.value) })
    }
  }

  componentDidMount() {
    window.addEventListener('mousedown', this.handlePageClick, false)
    if (this.buttonRef) {
      this.scrollableParent = DomUtils.getScrollableParent(this.buttonRef)
      this.scrollableParent.addEventListener('scroll', this.handleScroll)
    }
  }

  componentDidUpdate() {
    this.setPortalPosition()
  }

  componentWillUnmount() {
    window.removeEventListener('mousedown', this.handlePageClick, false)
    this.scrollableParent.removeEventListener('scroll', this.handleScroll, false)
  }

  setPortalPosition() {
    if (!this.portalRef || !this.buttonRef) {
      return
    }

    const buttonRect = this.buttonRef.getBoundingClientRect()
    const leftOffset = (buttonRect.left - (this.portalRef.offsetWidth - buttonRect.width)) + 10
    const tipHeight = 12
    let topOffset = buttonRect.top + this.buttonRef.offsetHeight + tipHeight
    let listHeight = this.portalRef.offsetHeight

    if (topOffset + listHeight > window.innerHeight) {
      topOffset = window.innerHeight - listHeight - 16
      this.portalRef.classList.add('hideTip')
    } else {
      this.portalRef.classList.remove('hideTip')
    }

    this.portalRef.style.top = `${topOffset + window.pageYOffset}px`
    this.portalRef.style.left = `${leftOffset + window.pageXOffset}px`
  }

  isValidDate(currentDate: Date, selectedDate: Date): boolean {
    if (!this.props.isValidDate) {
      return true
    }

    return this.props.isValidDate(currentDate, selectedDate)
  }

  handleScroll() {
    if (this.buttonRef) {
      if (DomUtils.isElementInViewport(this.buttonRef, this.scrollableParent)) {
        this.setPortalPosition()
      } else if (this.state.showPicker) {
        this.setState({ showPicker: false })
      }
    }
  }

  handlePageClick(e: Event) {
    let path = DomUtils.getEventPath(e)

    if (!this.itemMouseDown && !path.find(n => n.className === 'rdtPicker')) {
      this.dispatchChange()
      this.setState({ showPicker: false })
    }
  }

  handleDropdownClick() {
    this.dispatchChange()
    this.setState({ showPicker: !this.state.showPicker })
  }

  handleChange(newDate: Date) {
    let date = moment(newDate)
    if (this.props.timezone === 'utc') {
      date = DateUtils.getLocalTime(newDate)
    }

    this.setState({ date })
  }

  dispatchChange() {
    if (
      this.state.date
      && this.state.showPicker
      && this.state.date.toDate().getTime() !== (this.props.value && this.props.value.getTime())
    ) {
      this.props.onChange(this.state.date.toDate())
    }
  }

  renderDateTimePicker(timezoneDate: ?moment$Moment) {
    if (!this.state.showPicker) {
      return null
    }

    let body: any = document.body
    return ReactDOM.createPortal((
      <Portal innerRef={e => { this.portalRef = e }}>
        <DatetimeStyled
          input={false}
          value={timezoneDate}
          style={{ top: 0, right: 0 }}
          onChange={date => { this.handleChange(date) }}
          dateFormat="DD/MM/YYYY"
          timeFormat="hh:mm A"
          locale="en-gb"
          isValidDate={(currentDate, selectedDate) => this.isValidDate(currentDate, selectedDate)}
        />
      </Portal>
    ), body)
  }

  render() {
    let timezoneDate = this.state.date
    if (this.props.timezone === 'utc' && timezoneDate) {
      timezoneDate = DateUtils.getUtcTime(timezoneDate)
    }

    return (
      <Wrapper>
        <DropdownButtonStyled
          customRef={e => { this.buttonRef = e }}
          data-test-id="datetimePicker-dropdownButton"
          width={207}
          value={(timezoneDate && moment(timezoneDate).format('DD/MM/YYYY hh:mm A')) || '-'}
          centered
          useBold={this.props.useBold}
          onClick={() => { this.handleDropdownClick() }}
          onMouseDown={() => { this.itemMouseDown = true }}
          onMouseUp={() => { this.itemMouseDown = false }}
        />
        {this.renderDateTimePicker(timezoneDate)}
      </Wrapper>
    )
  }
}

export default DatetimePicker