/*
 * This file is part of caronte (https://github.com/eciavatta/caronte).
 * Copyright (c) 2020 Emiliano Ciavatta.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

import React, { Component } from "react";
import { withRouter } from "react-router-dom";

import ChartContainer from "react-timeseries-charts/lib/components/ChartContainer";
import ChartRow from "react-timeseries-charts/lib/components/ChartRow";
import Charts from "react-timeseries-charts/lib/components/Charts";
import LineChart from "react-timeseries-charts/lib/components/LineChart";
import MultiBrush from "react-timeseries-charts/lib/components/MultiBrush";
import Resizable from "react-timeseries-charts/lib/components/Resizable";
import YAxis from "react-timeseries-charts/lib/components/YAxis";
import { TimeRange, TimeSeries } from "pondjs";
import styler from "react-timeseries-charts/lib/js/styler";

import backend from "../backend";
import dispatcher from "../dispatcher";
import log from "../log";
import ChoiceField from "./fields/ChoiceField";
import "./Timeline.scss";

const minutes = 60 * 1000;
const maxTimelineRange = 24 * 60 * minutes;
import classNames from "classnames";

const leftSelectionPaddingMultiplier = 24;
const rightSelectionPaddingMultiplier = 8;

class Timeline extends Component {
  state = {
    metric: "connections_per_service",
  };

  constructor() {
    super();

    this.disableTimeSeriesChanges = false;
    this.selectionTimeout = null;
  }

  componentDidMount() {
    const urlParams = new URLSearchParams(this.props.location.search);
    this.setState({
      servicePortFilter: urlParams.get("service_port") || null,
      matchedRulesFilter: urlParams.getAll("matched_rules") || null,
    });

    this.loadStatistics(this.state.metric).then(() =>
      log.debug("Statistics loaded after mount")
    );
    dispatcher.register(
      "connections_filters",
      this.handleConnectionsFiltersCallback
    );
    dispatcher.register("connection_updates", this.handleConnectionUpdates);
    dispatcher.register("notifications", this.handleNotifications);
    dispatcher.register("pulse_timeline", this.handlePulseTimeline);
  }

  componentWillUnmount() {
    dispatcher.unregister(this.handleConnectionsFiltersCallback);
    dispatcher.unregister(this.handleConnectionUpdates);
    dispatcher.unregister(this.handleNotifications);
    dispatcher.unregister(this.handlePulseTimeline);
  }

  loadStatistics = async (metric) => {
    const urlParams = new URLSearchParams();
    urlParams.set("metric", metric);

    let columns = [];
    if (metric === "matched_rules") {
      let rules = await this.loadRules();
      if (this.state.matchedRulesFilter.length > 0) {
        this.state.matchedRulesFilter.forEach((id) => {
          urlParams.append("rules_ids", id);
        });
        columns = this.state.matchedRulesFilter;
      } else {
        columns = rules.map((r) => r.id);
      }
    } else {
      let services = await this.loadServices();
      const filteredPort = this.state.servicePortFilter;
      if (filteredPort && services[filteredPort]) {
        const service = services[filteredPort];
        services = {};
        services[filteredPort] = service;
      }

      columns = Object.keys(services);
      columns.forEach((port) => urlParams.append("ports", port));
    }

    const metrics = (await backend.get("/api/statistics?" + urlParams)).json;
    if (metrics.length === 0) {
      return;
    }

    const zeroFilledMetrics = [];
    const toTime = (m) => new Date(m["range_start"]).getTime();

    let i;
    let timeStart = toTime(metrics[0]) - minutes;
    for (i = 0; timeStart < 0 && i < metrics.length; i++) {
      // workaround to remove negative timestamps :(
      timeStart = toTime(metrics[i]) - minutes;
    }

    let timeEnd = toTime(metrics[metrics.length - 1]) + minutes;
    if (timeEnd - timeStart > maxTimelineRange) {
      timeEnd = timeStart + maxTimelineRange;

      const now = new Date().getTime();
      if (
        !this.lastDisplayNotificationTime ||
        this.lastDisplayNotificationTime + minutes < now
      ) {
        this.lastDisplayNotificationTime = now;
        dispatcher.dispatch("notifications", { event: "timeline.range.large" });
      }
    }

    for (let interval = timeStart; interval <= timeEnd; interval += minutes) {
      if (i < metrics.length && interval === toTime(metrics[i])) {
        const m = metrics[i++];
        m["range_start"] = new Date(m["range_start"]);
        zeroFilledMetrics.push(m);
      } else {
        const m = {};
        m["range_start"] = new Date(interval);
        m[metric] = {};
        columns.forEach((c) => (m[metric][c] = 0));
        zeroFilledMetrics.push(m);
      }
    }

    const series = new TimeSeries({
      name: "statistics",
      columns: ["time"].concat(columns),
      points: zeroFilledMetrics.map((m) =>
        [m["range_start"]].concat(
          columns.map((c) =>
            metric in m && m[metric] != null ? m[metric][c] || 0 : 0
          )
        )
      ),
    });

    const start = series.range().begin();
    const end = series.range().end();

    this.setState({
      metric,
      series,
      timeRange: new TimeRange(start, end),
      columns,
      start,
      end,
    });
  };

  loadServices = async () => {
    const services = (await backend.get("/api/services")).json;
    this.setState({ services });
    return services;
  };

  loadRules = async () => {
    const rules = (await backend.get("/api/rules")).json;
    this.setState({ rules });
    return rules;
  };

  createStyler = () => {
    if (this.state.metric === "matched_rules") {
      return styler(
        this.state.rules.map((rule) => {
          return { key: rule.id, color: rule.color, width: 2 };
        })
      );
    } else {
      return styler(
        Object.keys(this.state.services).map((port) => {
          return {
            key: port,
            color: this.state.services[port].color,
            width: 2,
          };
        })
      );
    }
  };

  handleTimeRangeChange = (timeRange) => {
    if (!this.disableTimeSeriesChanges) {
      this.setState({ timeRange });
    }
  };

  handleSelectionChange = (timeRange) => {
    this.disableTimeSeriesChanges = true;

    this.setState({ selection: timeRange });
    if (this.selectionTimeout) {
      clearTimeout(this.selectionTimeout);
    }
    this.selectionTimeout = setTimeout(() => {
      dispatcher.dispatch("timeline_updates", {
        from: timeRange.begin(),
        to: timeRange.end(),
      });
      this.selectionTimeout = null;
      this.disableTimeSeriesChanges = false;
    }, 1000);
  };

  handleConnectionsFiltersCallback = (payload) => {
    if (
      "service_port" in payload &&
      this.state.servicePortFilter !== payload["service_port"]
    ) {
      this.setState({ servicePortFilter: payload["service_port"] });
      this.loadStatistics(this.state.metric).then(() =>
        log.debug("Statistics reloaded after service port changed")
      );
    }
    if (
      "matched_rules" in payload &&
      this.state.matchedRulesFilter !== payload["matched_rules"]
    ) {
      this.setState({ matchedRulesFilter: payload["matched_rules"] });
      this.loadStatistics(this.state.metric).then(() =>
        log.debug("Statistics reloaded after matched rules changed")
      );
    }
  };

  handleConnectionUpdates = (payload) => {
    if (
      payload.from >= this.state.start &&
      payload.from < payload.to &&
      payload.to <= this.state.end
    ) {
      this.setState({
        selection: new TimeRange(payload.from, payload.to),
      });
      this.adjustSelection();
    }
  };

  handleNotifications = (payload) => {
    if (
      payload.event === "services.edit" &&
      this.state.metric !== "matched_rules"
    ) {
      this.loadStatistics(this.state.metric).then(() =>
        log.debug("Statistics reloaded after services updates")
      );
    } else if (
      payload.event.startsWith("rules") &&
      this.state.metric === "matched_rules"
    ) {
      this.loadStatistics(this.state.metric).then(() =>
        log.debug("Statistics reloaded after rules updates")
      );
    } else if (payload.event === "pcap.completed") {
      this.loadStatistics(this.state.metric).then(() =>
        log.debug("Statistics reloaded after pcap processed")
      );
    }
  };

  handlePulseTimeline = (payload) => {
    this.setState({ pulseTimeline: true });
    setTimeout(() => this.setState({ pulseTimeline: false }), payload.duration);
  };

  adjustSelection = () => {
    const seriesRange = this.state.series.range();
    const selection = this.state.selection;
    const delta = selection.end() - selection.begin();
    const start = Math.max(
      selection.begin().getTime() - delta * leftSelectionPaddingMultiplier,
      seriesRange.begin().getTime()
    );
    const end = Math.min(
      selection.end().getTime() + delta * rightSelectionPaddingMultiplier,
      seriesRange.end().getTime()
    );
    this.setState({ timeRange: new TimeRange(start, end) });
  };

  aggregateSeries = (func) => {
    const values = this.state.series
      .columns()
      .map((c) => this.state.series[func](c));
    return Math[func](...values);
  };

  render() {
    if (!this.state.series) {
      return null;
    }

    return (
      <footer className="footer">
        <div
          className={classNames("time-line", {
            "pulse-timeline": this.state.pulseTimeline,
          })}
        >
          <Resizable>
            <ChartContainer
              timeRange={this.state.timeRange}
              enableDragZoom={false}
              paddingTop={5}
              minDuration={60000}
              maxTime={this.state.end}
              minTime={this.state.start}
              paddingLeft={0}
              paddingRight={0}
              paddingBottom={0}
              enablePanZoom={true}
              utc={false}
              onTimeRangeChanged={this.handleTimeRangeChange}
            >
              <ChartRow height={this.props.height - 70}>
                <YAxis
                  id="axis1"
                  hideAxisLine
                  min={this.aggregateSeries("min")}
                  max={this.aggregateSeries("max")}
                  width="35"
                  type="linear"
                  transition={300}
                />
                <Charts>
                  <LineChart
                    axis="axis1"
                    series={this.state.series}
                    columns={this.state.columns}
                    style={this.createStyler()}
                    interpolation="curveBasis"
                  />

                  <MultiBrush
                    timeRanges={[this.state.selection]}
                    allowSelectionClear={false}
                    allowFreeDrawing={false}
                    onTimeRangeChanged={this.handleSelectionChange}
                  />
                </Charts>
              </ChartRow>
            </ChartContainer>
          </Resizable>

          <div className="metric-selection">
            <ChoiceField
              inline
              small
              keys={[
                "connections_per_service",
                "client_bytes_per_service",
                "server_bytes_per_service",
                "duration_per_service",
                "matched_rules",
              ]}
              values={[
                "connections_per_service",
                "client_bytes_per_service",
                "server_bytes_per_service",
                "duration_per_service",
                "matched_rules",
              ]}
              onChange={(metric) =>
                this.loadStatistics(metric).then(() =>
                  log.debug("Statistics loaded after metric changes")
                )
              }
              value={this.state.metric}
            />
          </div>
        </div>
      </footer>
    );
  }
}

export default withRouter(Timeline);