import React, {Component} from 'react';
import './Connections.scss';
import Connection from "../components/Connection";
import Table from 'react-bootstrap/Table';
import {Redirect} from 'react-router';
import {withRouter} from "react-router-dom";
import backend from "../backend";

class Connections extends Component {

    constructor(props) {
        super(props);
        this.state = {
            loading: false,
            connections: [],
            firstConnection: null,
            lastConnection: null,
            prevParams: null,
            flagRule: null,
            rules: null,
            queryString: null
        };

        this.scrollTopThreashold = 0.00001;
        this.scrollBottomThreashold = 0.99999;
        this.maxConnections = 500;
        this.queryLimit = 50;
    }

    componentDidMount() {
        this.loadConnections({limit: this.queryLimit})
            .then(() => this.setState({loaded: true}));
        if (this.props.initialConnection != null) {
            this.setState({selected: this.props.initialConnection.id});
            // TODO: scroll to initial connection
        }
    }

    connectionSelected = (c) => {
        this.setState({selected: c.id});
        this.props.onSelected(c);
    };

    componentDidUpdate(prevProps, prevState, snapshot) {
        if (this.state.loaded && prevProps.location.search !== this.props.location.search) {
            this.setState({queryString: this.props.location.search});
            this.loadConnections({limit: this.queryLimit})
                .then(() => console.log("Connections reloaded after query string update"));
        }
    }

    handleScroll = (e) => {
        let relativeScroll = e.currentTarget.scrollTop / (e.currentTarget.scrollHeight - e.currentTarget.clientHeight);
        if (!this.state.loading && relativeScroll > this.scrollBottomThreashold) {
            this.loadConnections({from: this.state.lastConnection.id, limit: this.queryLimit,})
                .then(() => console.log("Following connections loaded"));
        }
        if (!this.state.loading && relativeScroll < this.scrollTopThreashold) {
            this.loadConnections({to: this.state.firstConnection.id, limit: this.queryLimit,})
                .then(() => console.log("Previous connections loaded"));
        }
    };

    addServicePortFilter = (port) => {
        let urlParams = new URLSearchParams(this.props.location.search);
        urlParams.set("service_port", port);
        this.setState({queryString: "?" + urlParams});
    };

    async loadConnections(params) {
        let url = "/api/connections";
        const urlParams = new URLSearchParams(this.props.location.search);
        for (const [name, value] of Object.entries(params)) {
            urlParams.set(name, value);
        }

        this.setState({loading: true, prevParams: params});
        let res = (await backend.getJson(`${url}?${urlParams}`)).json;

        let connections = this.state.connections;
        let firstConnection = this.state.firstConnection;
        let lastConnection = this.state.lastConnection;

        if (params !== undefined && params.from !== undefined) {
            if (res.length > 0) {
                connections = this.state.connections.concat(res);
                lastConnection = connections[connections.length - 1];
                if (connections.length > this.maxConnections) {
                    connections = connections.slice(connections.length - this.maxConnections,
                        connections.length - 1);
                    firstConnection = connections[0];
                }
            }
        } else if (params !== undefined && params.to !== undefined) {
            if (res.length > 0) {
                connections = res.concat(this.state.connections);
                firstConnection = connections[0];
                if (connections.length > this.maxConnections) {
                    connections = connections.slice(0, this.maxConnections);
                    lastConnection = connections[this.maxConnections - 1];
                }
            }
        } else {
            if (res.length > 0) {
                connections = res;
                firstConnection = connections[0];
                lastConnection = connections[connections.length - 1];
            } else {
                connections = [];
                firstConnection = null;
                lastConnection = null;
            }
        }

        let flagRule = this.state.flagRule;
        let rules = this.state.rules;
        if (flagRule === null) {
            rules = (await backend.getJson("/api/rules")).json;
            flagRule = rules.filter(rule => {
                return rule.name === "flag";
            })[0];
        }

        this.setState({
            loading: false,
            connections: connections,
            rules: res,
            flagRule: flagRule,
            firstConnection: firstConnection,
            lastConnection: lastConnection
        });
    }

    render() {
        let redirect;
        let queryString = this.state.queryString !== null ? this.state.queryString : "";
        if (this.state.selected) {
            let format = this.props.match.params.format;
            format = format !== undefined ? "/" + format : "";
            redirect = <Redirect push to={`/connections/${this.state.selected}${format}${queryString}`} />;
        }

        let loading = null;
        if (this.state.loading) {
            loading = <tr>
                <td colSpan={9}>Loading...</td>
            </tr>;
        }

        return (
            <div className="connections" onScroll={this.handleScroll}>
                <div className="connections-header-padding"/>
                <Table borderless size="sm">
                    <thead>
                    <tr>
                        <th>service</th>
                        <th>srcip</th>
                        <th>srcport</th>
                        <th>dstip</th>
                        <th>dstport</th>
                        <th>duration</th>
                        <th>up</th>
                        <th>down</th>
                        <th>actions</th>
                    </tr>
                    </thead>
                    <tbody>
                    {
                        this.state.connections.map(c =>
                            <Connection key={c.id} data={c} onSelected={() => this.connectionSelected(c)}
                                        selected={this.state.selected === c.id} onMarked={marked => c.marked = marked}
                                        onEnabled={enabled => c.hidden = !enabled}
                                        containsFlag={c.matched_rules.includes(this.state.flagRule.id)}
                                        addServicePortFilter={this.addServicePortFilter}/>
                        )
                    }
                    {loading}
                    </tbody>
                </Table>

                {redirect}
            </div>
        );
    }

}


export default withRouter(Connections);