import React, { useState } from 'react';
import { Redirect, useHistory } from 'react-router-dom';
import {
	Panel,
	Form,
	ControlLabel,
	Button,
	ButtonGroup,
	Message,
	FormGroup,
} from 'rsuite';

import {
	NavBar,
	TimezonePicker,
	TimePicker,
	IntervalSelector,
} from '../components';
import dtToUTC from '../helpers/datetimeToUTC';
import { backend } from '../helpers/http-common';
import './styles/Availability.less';
import './styles/layout.less';

// NOTES:
// Even though Fullcalendar is supposed to work with timezone,
// it seems the custom rendering code breaks it.
// Possible Dates ID are also striped by custom code.
// That's why timezone and possible dates id are only set when posting an availability.

export default function Availability({
	currentUser,
	possibleDates,
	participant,
}) {
	const [availability, setAvailability] = useState([]);
	const [timezone, setTimezone] = useState(currentUser.timezone);
	const [times, setTimes] = useState({
		earliest: currentUser.earliest_time,
		latest: currentUser.latest_time,
	});
	const [status, setStatus] = useState({
		error: null,
		success: null,
		message: '',
	});

	const history = useHistory();

	const handleClear = () => {
		setAvailability([]);
	};

	const handleSelect = ({ start, end }) => {
		setAvailability([
			...availability,
			{
				start: start,
				end: end,
			},
		]);
	};

	const handleSubmit = () => {
		// Create a list of availability to post
		const availabilityList = availability.map((event) => {
			// Format start date to availability
			const selectedDate = event.start.toISOString().substring(0, 10);
			// Find the date id
			const [date] = possibleDates.filter(
				(date) => date.start === selectedDate,
			);

			return {
				participant_id: participant.id,
				possible_date_id: date.id,
				preference: false, // set to 'true" when implementing preference
				start_time: dtToUTC(event.start, timezone),
				end_time: dtToUTC(event.end, timezone),
			};
		});

		// Create availability post request
		const postAvailability = (data) => {
			return backend.post('/availability', data);
		};

		const requests = availabilityList.map((event) =>
			postAvailability(event),
		);

		Promise.all(requests)
			.then(function (results) {
				// Add confirmation message
				setStatus({
					success: true,
					error: false,
					message: 'Your availability has been added to the meeting.',
				});
			})
			.catch((error) => {
				setStatus({
					error: true,
					success: false,
					message:
						"Your availability couldn't be added to the meeting.",
				});
			});
	};

	const handleSelectTimezone = (value, item, event) => {
		setTimezone(item.timezone);
	};

	const handleClearTimezone = () => {
		setTimezone(currentUser.timezone);
	};

	const handleEarliest = (value, item, event) => {
		setTimes({
			...times,
			earliest: value,
		});
	};

	const handleLatest = (value, item, event) => {
		setTimes({
			...times,
			latest: value,
		});
	};

	if (possibleDates.length === 0) {
		return <Redirect to='/dashboard' />;
	}

	return (
		<>
			<NavBar title='Add your availability' />
			<Panel className={'app-container'}>
				<Form className={'av-container'}>
					<div className={'av-details'}>
						<FormGroup>
							<ControlLabel>Earliest time</ControlLabel>
							<TimePicker
								time={times.earliest}
								handleSelect={handleEarliest}
							/>
						</FormGroup>
						<FormGroup>
							<ControlLabel>Latest time</ControlLabel>
							<TimePicker
								time={times.latest}
								handleSelect={handleLatest}
							/>
						</FormGroup>
						<FormGroup className='av-timezone'>
							<ControlLabel>Timezone</ControlLabel>
							<TimezonePicker
								timezone={timezone}
								handleSelect={handleSelectTimezone}
								handleClean={handleClearTimezone}
							/>
						</FormGroup>
						<div className='av-controls'>
							{!status.success && (
								<ButtonGroup justified>
									<Button
										appearance='ghost'
										block
										size='lg'
										disabled={availability.length === 0}
										onClick={() => handleClear()}
									>
										Clear selection
									</Button>
									<Button
										appearance='primary'
										size='lg'
										block
										disabled={availability.length === 0}
										onClick={handleSubmit}
									>
										Save your availability
									</Button>
								</ButtonGroup>
							)}

							{status.success && (
								<ButtonGroup justified>
									<Button
										appearance='ghost'
										size='lg'
										block
										onClick={() =>
											history.push('dashboard')
										}
									>
										Go to dashboard
									</Button>
									<Button
										appearance='primary'
										size='lg'
										block
										onClick={() => history.push('invite')}
									>
										Invite Participants
									</Button>
								</ButtonGroup>
							)}
							{(status.error || status.success) && (
								<Message
									type={status.success ? 'success' : 'error'}
									description={status.message}
								/>
							)}
						</div>
					</div>
					<div className={'interval-selector'}>
						<Message
							showIcon
							type='info'
							description='Select your availability on the calendar.'
						/>
						<IntervalSelector
							selectedDates={possibleDates}
							availability={availability}
							setAvailability={setAvailability}
							handleSelect={handleSelect}
							handleClear={handleClear}
							slotMinTime={times.earliest}
							slotMaxTime={times.latest}
						/>
					</div>
				</Form>
			</Panel>
		</>
	);
}