import React, { useEffect, useState } from 'react';
import { Websocket } from '@/plugins/Websocket';
import { ServerContext } from '@/state/server';
import { getWebsocketToken } from '@/api/server';
import ContentContainer from '@/components/elements/ContentContainer';
import { CSSTransition } from 'react-transition-group';
import Spinner from '@/components/elements/Spinner';
import tw from 'twin.macro';

const reconnectErrors = [
    'jwt: exp claim is invalid',
    'jwt: created too far in past (denylist)',
];

export default () => {
    let updatingToken = false;
    const [ error, setError ] = useState<'connecting' | string>('');
    const { connected, instance } = ServerContext.useStoreState(state => state.socket);
    const uuid = ServerContext.useStoreState(state => state.server.data?.uuid);
    const setServerStatus = ServerContext.useStoreActions(actions => actions.status.setServerStatus);
    const { setInstance, setConnectionState } = ServerContext.useStoreActions(actions => actions.socket);

    const updateToken = (uuid: string, socket: Websocket) => {
        if (updatingToken) return;

        updatingToken = true;
        getWebsocketToken(uuid)
            .then(data => socket.setToken(data.token, true))
            .catch(error => console.error(error))
            .then(() => {
                updatingToken = false;
            });
    };

    const connect = (uuid: string) => {
        const socket = new Websocket();

        socket.on('auth success', () => setConnectionState(true));
        socket.on('SOCKET_CLOSE', () => setConnectionState(false));
        socket.on('SOCKET_ERROR', () => {
            setError('connecting');
            setConnectionState(false);
        });
        socket.on('status', (status) => setServerStatus(status));

        socket.on('daemon error', message => {
            console.warn('Got error message from daemon socket:', message);
        });

        socket.on('token expiring', () => updateToken(uuid, socket));
        socket.on('token expired', () => updateToken(uuid, socket));
        socket.on('jwt error', (error: string) => {
            setConnectionState(false);
            console.warn('JWT validation error from wings:', error);

            if (reconnectErrors.find(v => error.toLowerCase().indexOf(v) >= 0)) {
                updateToken(uuid, socket);
            } else {
                setError('There was an error validating the credentials provided for the websocket. Please refresh the page.');
            }
        });

        socket.on('transfer status', (status: string) => {
            if (status === 'starting' || status === 'success') {
                return;
            }

            // This code forces a reconnection to the websocket which will connect us to the target node instead of the source node
            // in order to be able to receive transfer logs from the target node.
            socket.close();
            setError('connecting');
            setConnectionState(false);
            setInstance(null);
            connect(uuid);
        });

        getWebsocketToken(uuid)
            .then(data => {
                // Connect and then set the authentication token.
                socket.setToken(data.token).connect(data.socket);

                // Once that is done, set the instance.
                setInstance(socket);
            })
            .catch(error => console.error(error));
    };

    useEffect(() => {
        connected && setError('');
    }, [ connected ]);

    useEffect(() => {
        return () => {
            instance && instance.close();
        };
    }, [ instance ]);

    useEffect(() => {
        // If there is already an instance or there is no server, just exit out of this process
        // since we don't need to make a new connection.
        if (instance || !uuid) {
            return;
        }

        connect(uuid);
    }, [ uuid ]);

    return (
        error ?
            <CSSTransition timeout={150} in appear classNames={'fade'}>
                <div css={tw`bg-red-500 py-2`}>
                    <ContentContainer css={tw`flex items-center justify-center`}>
                        {error === 'connecting' ?
                            <>
                                <Spinner size={'small'}/>
                                <p css={tw`ml-2 text-sm text-red-100`}>
                                    We&apos;re having some trouble connecting to your server, please wait...
                                </p>
                            </>
                            :
                            <p css={tw`ml-2 text-sm text-white`}>
                                {error}
                            </p>
                        }
                    </ContentContainer>
                </div>
            </CSSTransition>
            :
            null
    );
};