<template>
  <div class="d-flex flex-column flex-fill">
    <UIBoxHeader
      icon="ruler-vertical"
      :title="title"
      :closeCallback="close"
      class="rounded-0"
    />
    <div class="d-flex flex-fill">
      <DiagramLegend>
        <div class="legend">
          <span style="background-color: red"></span>
          {{ yearCompare }}
        </div>
        <div class="legend">
          <span style="background-color: orange"></span> Q25%
        </div>
        <div class="legend">
          <span style="background-color: black"></span> Median
        </div>
        <div class="legend">
          <span style="background-color: purple"></span> Q75%
        </div>
        <div class="legend">
          <span style="background-color: lightsteelblue"></span>
          Long-term Amplitude
        </div>
        <div>
          <button
            @click="downloadPDF"
            type="button"
            class="btn btn-sm btn-info d-block w-100 mt-2"
          >
            <translate>Export to PDF</translate>
          </button>
        </div>
      </DiagramLegend>
      <div
        class="d-flex flex-fill justify-content-center align-items-center"
        :id="containerId"
      >
        <div v-if="!longtermWaterlevels.length">
          <translate>No data available.</translate>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
/* This is Free Software under GNU Affero General Public License v >= 3.0
 * without warranty, see README.md and license for details.
 *
 * SPDX-License-Identifier: AGPL-3.0-or-later
 * License-Filename: LICENSES/AGPL-3.0.txt
 *
 * Copyright (C) 2019 by via donau
 *   – Österreichische Wasserstraßen-Gesellschaft mbH
 * Software engineering by Intevation GmbH
 *
 * Author(s):
 * Markus Kottländer <markus.kottlaender@intevation.de>
 * Fadi Abbud <fadi.abbud@intevation.de>
 */

import { mapState, mapGetters } from "vuex";
import * as d3 from "d3";
import debounce from "debounce";
import { startOfYear, endOfYear } from "date-fns";
import jsPDF from "jspdf";
import canvg from "canvg";

export default {
  components: {
    DiagramLegend: () => import("@/components/DiagramLegend")
  },
  data() {
    return {
      containerId: "hydrologicalconditions-diagram-container",
      svg: null,
      diagram: null,
      navigation: null,
      dimensions: null,
      extent: null,
      scale: null,
      axes: null
    };
  },
  computed: {
    ...mapState("application", ["paneSetup"]),
    ...mapState("gauges", [
      "longtermWaterlevels",
      "yearWaterlevels",
      "yearCompare",
      "longtermInterval"
    ]),
    ...mapGetters("gauges", ["selectedGauge"]),
    title() {
      return this.$gettext("Hydrological Conditions");
    }
  },
  watch: {
    paneSetup() {
      this.$nextTick(() => this.drawDiagram());
    },
    longtermWaterlevels() {
      this.drawDiagram();
    },
    yearWaterlevels() {
      this.drawDiagram();
    }
  },
  methods: {
    close() {
      this.$store.commit(
        "application/paneSetup",
        this.paneSetup === "GAUGE_WATERLEVEL_HYDROLOGICALCONDITIONS"
          ? "GAUGE_WATERLEVEL"
          : "DEFAULT"
      );
    },
    downloadPDF() {
      var svg = document.getElementById(this.containerId).innerHTML;
      if (svg) {
        svg = svg.replace(/\r?\n|\r/g, "").trim();
      }
      var pdf = new jsPDF("l", "mm", "a3");
      var canvas = document.createElement("canvas");
      canvas.width = window.innerWidth;
      canvas.height = window.innerHeight / 2;
      canvg(canvas, svg, {
        ignoreMouse: true,
        ignoreAnimation: true,
        ignoreDimensions: true
      });
      var imgData = canvas.toDataURL("image/png");
      pdf.addImage(imgData, "PNG", 40, 60, 380, 130);
      this.addDiagramTitle(pdf, 108, 30, 22, "steelblue");
      this.addDiagramLegend(pdf, 60, 190, "black");
      pdf.save(
        this.selectedGauge.properties.objname +
          " Hydrological-condition Diagram.pdf"
      );
    },
    // Gauge info as title
    addDiagramTitle(pdf, x, y, size, color) {
      let gaugeInfo =
        this.selectedGauge.properties.objname +
        " (" +
        this.selectedGauge.id
          .split(".")[1]
          .replace(/[()]/g, "")
          .split(",")[3] +
        "): Hydrological Conditions " +
        this.longtermInterval.join(" - ");
      pdf.setTextColor(color);
      pdf.setFontSize(22);
      pdf.setFontStyle("bold");
      pdf.text(gaugeInfo, 108, 30);
    },
    // Diagram legend
    addDiagramLegend(pdf, x, y, color) {
      pdf.setFontSize(10);
      pdf.setTextColor(color);
      pdf.setDrawColor("white");
      pdf.setFillColor("red");
      pdf.circle(x, y, 2, "FD");
      pdf.text(x + 3, y + 1, "" + this.yearCompare);
      pdf.setFillColor("orange");
      pdf.circle(x, y + 5, 2, "FD");
      pdf.text(x + 3, y + 6, "Q25%");
      pdf.setFillColor("black");
      pdf.circle(x, y + 10, 2, "FD");
      pdf.text(x + 3, y + 11, "Median ");
      pdf.setFillColor("purple");
      pdf.circle(x, y + 15, 2, "FD");
      pdf.text(x + 3, y + 16, "Q75%");
      pdf.setFillColor("lightsteelblue");
      pdf.circle(x, y + 20, 2, "FD");
      pdf.text(x + 3, y + 21, "Long-term Amplitude");
    },
    drawDiagram() {
      // remove old diagram
      d3.select("#" + this.containerId + " svg").remove();
      if (!this.selectedGauge || !this.longtermWaterlevels.length) return;
      // PREPARE HELPERS

      // HDC/LDC/MW for the selected gauge
      const refWaterLevels = JSON.parse(
        this.selectedGauge.properties.reference_water_levels
      );

      // dimensions (widths, heights, margins)
      this.dimensions = this.getDimensions();

      // get min/max values for date and waterlevel axis
      this.extent = this.getExtent(refWaterLevels);

      // scaling helpers
      this.scale = this.getScale();

      // creating the axes based on the scales
      this.axes = this.getAxes();

      // DRAW DIAGRAM/NAVIGATION AREAS

      // create svg
      this.svg = d3
        .select("#" + this.containerId)
        .append("svg")
        .attr("width", "100%")
        .attr("height", "100%");

      // create container for main diagram
      this.diagram = this.svg
        .append("g")
        .attr("class", "main")
        .attr(
          "transform",
          `translate(${this.dimensions.mainMargin.left}, ${
            this.dimensions.mainMargin.top
          })`
        );

      // create container for navigation diagram
      this.navigation = this.svg
        .append("g")
        .attr("class", "nav")
        .attr(
          "transform",
          `translate(${this.dimensions.navMargin.left}, ${
            this.dimensions.navMargin.top
          })`
        );

      // define visible area, everything outside this area will be hidden
      this.svg
        .append("defs")
        .append("clipPath")
        .attr("id", "clip")
        .append("rect")
        .attr("width", this.dimensions.width)
        .attr("height", this.dimensions.mainHeight);

      // DRAW DIAGRAM PARTS

      // Each drawSomething function (with the exception of drawRefLines)
      // returns a fuction to update the respective chart/area/etc. These
      // updater functions are used by the zoom feature to rescale all elements.
      const updaters = [];

      // draw
      this.drawRefLines(refWaterLevels); // static, doesn't need an updater
      updaters.push(this.drawAxes());
      updaters.push(this.drawNowLines());
      updaters.push(this.drawWaterlevelMinMaxAreaChart());
      updaters.push(this.drawWaterlevelLineChart("median"));
      updaters.push(this.drawWaterlevelLineChart("q25"));
      updaters.push(this.drawWaterlevelLineChart("q75"));
      updaters.push(this.drawWaterlevelLineChart("mean", this.yearWaterlevels));

      // INTERACTIONS

      // create rectanlge on the main chart area to capture mouse events
      const eventRect = this.svg
        .append("rect")
        .attr("class", "zoom")
        .attr("width", this.dimensions.width)
        .attr("height", this.dimensions.mainHeight)
        .attr(
          "transform",
          `translate(${this.dimensions.mainMargin.left}, ${
            this.dimensions.mainMargin.top
          })`
        );

      this.createZoom(updaters, eventRect);
      this.createTooltips(eventRect);
      this.setInlineStyles();
    },
    setInlineStyles() {
      this.svg.selectAll(".hide").attr("fill-opacity", 0);
      this.svg
        .selectAll(".line")
        .attr("clip-path", "url(#clip)")
        .attr("stroke-width", 2)
        .attr("fill", "none");
      this.svg.selectAll(".line.mean").attr("stroke", "red");
      this.svg.selectAll(".line.median").attr("stroke", "black");
      this.svg.selectAll(".line.q25").attr("stroke", "orange");
      this.svg.selectAll(".line.q75").attr("stroke", "purple");
      this.svg
        .selectAll(".area")
        .attr("clip-path", "url(#clip)")
        .attr("stroke", "none")
        .attr("fill", "lightsteelblue");
      this.svg
        .selectAll(".hdc-line, .ldc-line, .mw-line")
        .attr("stroke-width", 1)
        .attr("fill", "none")
        .attr("clip-path", "url(#clip)");
      this.svg.selectAll(".hdc-line").attr("stroke", "red");
      this.svg.selectAll(".ldc-line").attr("stroke", "green");
      this.svg.selectAll(".mw-line").attr("stroke", "grey");
      this.svg
        .selectAll(".ref-waterlevel-label")
        .style("font-size", "11px")
        .attr("fill", "#999");
      this.svg
        .selectAll(".now-line")
        .attr("stroke", "#999")
        .attr("stroke-width", 1)
        .attr("stroke-dasharray", "5, 5")
        .attr("clip-path", "url(#clip)");
      this.svg
        .selectAll(".now-line-label")
        .attr("fill", "#999")
        .style("font-size", "11px");
      this.svg
        .selectAll(".tick line")
        .attr("stroke-dasharray", 5)
        .attr("stroke", " #ccc");
      this.svg.selectAll(".tick text").attr("fill", "black");
      this.svg.selectAll(".domain").attr("stroke", "black");

      this.svg
        .selectAll(".zoom")
        .attr("cursor", "move")
        .attr("fill", "none")
        .attr("pointer-events", "all");
      this.svg
        .selectAll(".brush .selection")
        .attr("stroke", "none")
        .attr("fill-opacity", 0.2);
      this.svg
        .selectAll(".brush .handle")
        .attr("stroke", "rgba(23, 162, 184, 0.5)")
        .attr("fill", "rgba(23, 162, 184, 0.5)");
      this.svg.selectAll(".chart-dots").attr("clip-path", "url(#clip)");
      this.svg
        .selectAll(".chart-dots .chart-dot")
        .attr("fill", "black")
        .attr("stroke", "black")
        .attr("stroke-opacity", 0)
        .style("pointer-events", "none")
        .attr("fill-opacity", 0)
        .transition()
        .attr("fill-opacity", "0.1s");
      this.svg
        .selectAll(".chart-tooltip")
        .attr("fill-opacity", 0)
        .transition()
        .attr("fill-opacity", "0.3s");
      this.svg
        .selectAll(".chart-tooltip rect")
        .attr("fill", "#fff")
        .attr("stroke", "#ccc");
      this.svg
        .selectAll(".chart-tooltip text")
        .attr("fill", "666")
        .style("font-size", "0.8em");
    },
    getDimensions() {
      // dimensions and margins
      const svgWidth = document.querySelector("#" + this.containerId)
        .clientWidth;
      const svgHeight = document.querySelector("#" + this.containerId)
        .clientHeight;
      const mainMargin = { top: 20, right: 20, bottom: 110, left: 80 };
      const navMargin = {
        top: svgHeight - mainMargin.top - 65,
        right: 20,
        bottom: 30,
        left: 80
      };
      const width = +svgWidth - mainMargin.left - mainMargin.right;
      const mainHeight = +svgHeight - mainMargin.top - mainMargin.bottom;
      const navHeight = +svgHeight - navMargin.top - navMargin.bottom;

      return { width, mainHeight, navHeight, mainMargin, navMargin };
    },
    getExtent(refWaterLevels) {
      const waterlevelsRelevantForExtent = [];
      this.longtermWaterlevels.forEach(wl => {
        waterlevelsRelevantForExtent.push(wl.min, wl.max);
      });
      waterlevelsRelevantForExtent.push(
        refWaterLevels.HDC + (refWaterLevels.HDC - refWaterLevels.LDC) / 8,
        Math.max(
          refWaterLevels.LDC - (refWaterLevels.HDC - refWaterLevels.LDC) / 4,
          0
        )
      );
      return {
        // set min/max values for the date axis
        date: [startOfYear(new Date()), endOfYear(new Date())],
        // set min/max values for the waterlevel axis
        // including HDC (+ 1/8 HDC-LDC) and LDC (- 1/4 HDC-LDC)
        waterlevel: d3.extent(waterlevelsRelevantForExtent)
      };
    },
    getScale() {
      // scaling helpers to convert real world values into pixels
      const x = d3.scaleTime().range([0, this.dimensions.width]);
      const y = d3.scaleLinear().range([this.dimensions.mainHeight, 0]);
      const x2 = d3.scaleTime().range([0, this.dimensions.width]);
      const y2 = d3.scaleLinear().range([this.dimensions.navHeight, 0]);

      // setting the min and max values for the diagram axes
      x.domain(d3.extent(this.extent.date));
      y.domain(this.extent.waterlevel);
      x2.domain(x.domain());
      y2.domain(y.domain());

      return { x, y, x2, y2 };
    },
    getAxes() {
      return {
        x: d3
          .axisTop(this.scale.x)
          .tickSizeInner(this.dimensions.mainHeight)
          .tickSizeOuter(0)
          .tickFormat(date => {
            // make the x-axis label formats dynamic, based on zoom
            // but never display year numbers since they don't make any sense in
            // this diagram
            return (d3.timeSecond(date) < date
              ? d3.timeFormat(".%L")
              : d3.timeMinute(date) < date
              ? d3.timeFormat(":%S")
              : d3.timeHour(date) < date
              ? d3.timeFormat("%I:%M")
              : d3.timeDay(date) < date
              ? d3.timeFormat("%I %p")
              : d3.timeMonth(date) < date
              ? d3.timeWeek(date) < date
                ? d3.timeFormat("%a %d")
                : d3.timeFormat("%b %d")
              : d3.timeFormat("%B"))(date);
          }),
        y: d3
          .axisRight(this.scale.y)
          .tickSizeInner(this.dimensions.width)
          .tickSizeOuter(0),
        x2: d3.axisBottom(this.scale.x2)
      };
    },
    drawNowLines() {
      const nowLine = d3
        .line()
        .x(d => this.scale.x(d.x))
        .y(d => this.scale.y(d.y));

      const nowLabel = selection => {
        selection.attr(
          "transform",
          `translate(${this.scale.x(new Date())}, ${this.scale.y(
            this.extent.waterlevel[1] - 16
          )})`
        );
      };

      // draw in main
      this.diagram
        .append("path")
        .datum([
          { x: new Date(), y: this.extent.waterlevel[0] },
          { x: new Date(), y: this.extent.waterlevel[1] - 20 }
        ])
        .attr("class", "now-line")
        .attr("d", nowLine);
      this.diagram // label
        .append("text")
        .text(this.$gettext("Now"))
        .attr("class", "now-line-label")
        .attr("text-anchor", "middle")
        .call(nowLabel);

      // draw in nav
      this.navigation
        .append("path")
        .datum([
          { x: new Date(), y: this.extent.waterlevel[0] },
          { x: new Date(), y: this.extent.waterlevel[1] - 20 }
        ])
        .attr("class", "now-line")
        .attr(
          "d",
          d3
            .line()
            .x(d => this.scale.x2(d.x))
            .y(d => this.scale.y2(d.y))
        );

      return () => {
        this.diagram.select(".now-line").attr("d", nowLine);
        this.diagram.select(".now-line-label").call(nowLabel);
      };
    },
    drawAxes() {
      this.diagram
        .append("g")
        .attr("class", "axis--x")
        .attr("transform", `translate(0, ${this.dimensions.mainHeight})`)
        .call(this.axes.x)
        .selectAll(".tick text")
        .attr("y", 15);
      this.diagram // label
        .append("text")
        .text(this.$gettext("Waterlevel [cm]"))
        .attr("text-anchor", "middle")
        .attr(
          "transform",
          `translate(-45, ${this.dimensions.mainHeight / 2}) rotate(-90)`
        );
      this.diagram
        .append("g")
        .call(this.axes.y)
        .selectAll(".tick text")
        .attr("x", -25);

      this.navigation
        .append("g")
        .attr("class", "axis axis--x")
        .attr("transform", `translate(0, ${this.dimensions.navHeight})`)
        .call(this.axes.x2);

      return () => {
        this.diagram
          .select(".axis--x")
          .call(this.axes.x)
          .selectAll(".tick text")
          .attr("y", 15);
      };
    },
    drawWaterlevelMinMaxAreaChart() {
      const areaChart = isNav =>
        d3
          .area()
          .x(d => this.scale[isNav ? "x2" : "x"](d.date))
          .y0(d => this.scale[isNav ? "y2" : "y"](d.min))
          .y1(d => this.scale[isNav ? "y2" : "y"](d.max));

      this.diagram
        .append("path")
        .datum(this.longtermWaterlevels)
        .attr("class", "area")
        .attr("d", areaChart());

      this.navigation
        .append("path")
        .datum(this.longtermWaterlevels)
        .attr("class", "area")
        .attr("d", areaChart(true));

      return () => {
        this.diagram.select(".area").attr("d", areaChart());
      };
    },
    drawWaterlevelLineChart(type, data) {
      const lineChart = type =>
        d3
          .line()
          .x(d => this.scale.x(d.date))
          .y(d => this.scale.y(d[type]))
          .curve(d3.curveLinear);
      this.diagram
        .append("path")
        .attr("class", "line " + type)
        .datum(data || this.longtermWaterlevels)
        .attr("d", lineChart(type));

      return () => {
        this.diagram.select(".line." + type).attr("d", lineChart(type));
      };
    },
    drawRefLines(refWaterLevels) {
      const refWaterlevelLine = d3
        .line()
        .x(d => this.scale.x(d.x))
        .y(d => this.scale.y(d.y));

      // HDC
      this.diagram
        .append("path")
        .datum([
          { x: 0, y: refWaterLevels.HDC },
          { x: this.extent.date[1], y: refWaterLevels.HDC }
        ])
        .attr("class", "hdc-line")
        .attr("d", refWaterlevelLine);
      this.diagram // label
        .append("text")
        .text(`HDC (${refWaterLevels.HDC})`)
        .attr("class", "ref-waterlevel-label")
        .attr("x", 5)
        .attr("y", this.scale.y(refWaterLevels.HDC) - 3);
      // LDC
      this.diagram
        .append("path")
        .datum([
          { x: 0, y: refWaterLevels.LDC },
          { x: this.extent.date[1], y: refWaterLevels.LDC }
        ])
        .attr("class", "ldc-line")
        .attr("d", refWaterlevelLine);
      this.diagram // label
        .append("text")
        .text(`LDC (${refWaterLevels.LDC})`)
        .attr("class", "ref-waterlevel-label")
        .attr("x", 5)
        .attr("y", this.scale.y(refWaterLevels.LDC) - 3);
      // MW
      this.diagram
        .append("path")
        .datum([
          { x: 0, y: refWaterLevels.MW },
          { x: this.extent.date[1], y: refWaterLevels.MW }
        ])
        .attr("class", "mw-line")
        .attr("d", refWaterlevelLine);
      this.diagram // label
        .append("text")
        .text(`MW (${refWaterLevels.MW})`)
        .attr("class", "ref-waterlevel-label")
        .attr("x", 5)
        .attr("y", this.scale.y(refWaterLevels.MW) - 3);
    },
    createZoom(updaters, eventRect) {
      const brush = d3
        .brushX()
        .handleSize(4)
        .extent([[0, 0], [this.dimensions.width, this.dimensions.navHeight]]);

      const zoom = d3
        .zoom()
        .scaleExtent([1, Infinity])
        .translateExtent([
          [0, 0],
          [this.dimensions.width, this.dimensions.mainHeight]
        ])
        .extent([[0, 0], [this.dimensions.width, this.dimensions.mainHeight]]);

      brush.on("brush end", () => {
        if (d3.event.sourceEvent && d3.event.sourceEvent.type === "zoom")
          return; // ignore brush-by-zoom
        let s = d3.event.selection || this.scale.x2.range();
        this.scale.x.domain(s.map(this.scale.x2.invert, this.scale.x2));
        updaters.forEach(u => u && u());
        this.setInlineStyles();
        this.svg
          .select(".zoom")
          .call(
            zoom.transform,
            d3.zoomIdentity
              .scale(this.dimensions.width / (s[1] - s[0]))
              .translate(-s[0], 0)
          );
      });

      zoom.on("zoom", () => {
        if (d3.event.sourceEvent && d3.event.sourceEvent.type === "brush")
          return; // ignore zoom-by-brush
        let t = d3.event.transform;
        this.scale.x.domain(t.rescaleX(this.scale.x2).domain());
        updaters.forEach(u => u && u());
        this.setInlineStyles();
        this.navigation
          .select(".brush")
          .call(brush.move, this.scale.x.range().map(t.invertX, t));
      });
      zoom.on("start", () => {
        this.svg.select(".chart-dot").style("opacity", 0);
        this.svg.select(".chart-tooltip").style("opacity", 0);
      });

      this.navigation
        .append("g")
        .attr("class", "brush")
        .call(brush)
        .call(brush.move, this.scale.x.range());

      eventRect.call(zoom);
    },
    createTooltips(eventRect) {
      // create clippable container for the dot
      this.diagram
        .append("g")
        .attr("class", "chart-dots")
        .append("circle")
        .attr("class", "chart-dot")
        .attr("r", 4);

      // create container for the tooltip
      const tooltip = this.diagram.append("g").attr("class", "chart-tooltip");
      tooltip
        .append("rect")
        .attr("rx", "0.25em")
        .attr("ry", "0.25em");

      // create container for multiple text rows
      const tooltipText = tooltip.append("text").attr("text-anchor", "middle");

      // padding inside the tooltip box and diagram padding to determine left
      // and right offset from the diagram boundaries for the tooltip position.
      const tooltipPadding = 10;
      const diagramPadding = 5;

      eventRect
        .on("mouseover", () => {
          this.diagram.select(".chart-dot").style("opacity", 1);
          this.diagram.select(".chart-tooltip").style("opacity", 1);
        })
        .on("mouseout", () => {
          this.diagram.select(".chart-dot").style("opacity", 0);
          this.diagram.select(".chart-tooltip").style("opacity", 0);
        })
        .on("mousemove", () => {
          // find data point closest to mouse
          const x0 = this.scale.x.invert(
              d3.mouse(document.querySelector(".zoom"))[0]
            ),
            i = d3.bisector(d => d.date).left(this.longtermWaterlevels, x0, 1),
            d0 = this.longtermWaterlevels[i - 1],
            d1 = this.longtermWaterlevels[i] || d0,
            d = x0 - d0.date > d1.date - x0 ? d1 : d0;

          const coords = {
            x: this.scale.x(d.date),
            y: this.scale.y(d.median)
          };

          // position the dot
          this.diagram
            .select(".chart-dot")
            .style("opacity", 1)
            .attr("transform", `translate(${coords.x}, ${coords.y})`);

          // remove current texts
          tooltipText.selectAll("tspan").remove();

          // write date
          tooltipText
            .append("tspan")
            .attr("dominant-baseline", "hanging")
            .attr("text-anchor", "middle")
            .text(
              d.date.toLocaleString([], {
                year: "2-digit",
                month: "2-digit",
                day: "2-digit"
              })
            );

          tooltipText
            .append("tspan")
            .attr("x", 0)
            .attr("y", 0)
            .attr("dy", "1.4em")
            .attr("dominant-baseline", "hanging")
            .attr("text-anchor", "middle")
            .text(`Q75%: ${d.q75} cm`);
          tooltipText
            .append("tspan")
            .attr("x", 0)
            .attr("y", 0)
            .attr("dy", "2.6em")
            .attr("dominant-baseline", "hanging")
            .attr("text-anchor", "middle")
            .text(`Median: ${d.median} cm`);
          tooltipText
            .append("tspan")
            .attr("x", 0)
            .attr("y", 0)
            .attr("dy", "3.8em")
            .attr("dominant-baseline", "hanging")
            .attr("text-anchor", "middle")
            .text(`Q25%: ${d.q25} cm`);
          tooltipText
            .append("tspan")
            .attr("x", 0)
            .attr("y", 0)
            .attr("dy", "5em")
            .attr("dominant-baseline", "hanging")
            .attr("text-anchor", "middle")
            .text(`Max: ${d.max} cm`);
          tooltipText
            .append("tspan")
            .attr("x", 0)
            .attr("y", 0)
            .attr("dy", "6.2em")
            .attr("dominant-baseline", "hanging")
            .attr("text-anchor", "middle")
            .text(`Min: ${d.min} cm`);

          const dYear = this.yearWaterlevels.find(
            ywl => ywl.date.getTime() === d.date.getTime()
          );
          if (dYear) {
            tooltipText
              .append("tspan")
              .attr("x", 0)
              .attr("y", 0)
              .attr("dy", "7.4em")
              .attr("dominant-baseline", "hanging")
              .attr("text-anchor", "middle")
              .text(`${this.yearCompare}: ${dYear.mean.toFixed(1)} cm`);
          }

          // get text dimensions
          const textBBox = tooltipText.node().getBBox();

          this.diagram
            .selectAll(".chart-tooltip text tspan")
            .attr("x", textBBox.width / 2 + tooltipPadding)
            .attr("y", tooltipPadding);

          // position and scale tooltip box
          const xMax =
            this.dimensions.width -
            (textBBox.width + diagramPadding + tooltipPadding * 2);
          const tooltipX = Math.max(
            diagramPadding,
            Math.min(coords.x - (textBBox.width + tooltipPadding * 2) / 2, xMax)
          );
          let tooltipY = coords.y - (textBBox.height + tooltipPadding * 2) - 10;
          if (coords.y < textBBox.height + tooltipPadding * 2) {
            tooltipY = coords.y + 10;
          }

          this.diagram
            .select(".chart-tooltip")
            .style("opacity", 1)
            .attr("transform", `translate(${tooltipX}, ${tooltipY})`)
            .select("rect")
            .attr("width", textBBox.width + tooltipPadding * 2)
            .attr("height", textBBox.height + tooltipPadding * 2);
        });
    }
  },
  created() {
    window.addEventListener("resize", debounce(this.drawDiagram), 100);
  },
  mounted() {
    this.drawDiagram();
  },
  updated() {
    this.drawDiagram();
  },
  destroyed() {
    window.removeEventListener("resize", debounce(this.drawDiagram));
  }
};
</script>