Real oil prices annotated line chart

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/d3-annotation/1.12.1/d3-annotation.min.js"></script>
  <style>
    .axis path,
    .axis line {
      fill: none;
      stroke: #000;
      shape-rendering: crispEdges;
    }
    .x.axis path {
      display: none;
    }
    .overlay {
      fill: none;
      pointer-events: all;
    }
    .focus circle {
      fill: none;
      stroke: steelblue;
    }
    .hover-line {
      stroke: #6F257F;
      stroke-width: 2px;
      stroke-dasharray: 3,3;
    }

.annotation path {
    stroke: #E8336D;
    fill: none;
  }

.annotation path.connector-arrow,
  .annotation path.connector-dot,
  .title text, .annotation text {
    fill: #E8336D;
  }

.annotation-note-bg {
    fill: rgba(0, 0, 0, 0);
  }

.annotation-note-title, text.title {
    font-weight: bold;
  }

text.title {
    font-size: 1.2em
  }

.badge path {
    stroke: #00cc66;
    stroke-width: 3px;
    stroke-linecap: round;
  }
  .annotation.badge path.subject-pointer, .annotation.badge path.subject,  .annotation.badge path.subject-ring {
    fill: #00cc66;
    stroke-width: 3px;
    stroke-linecap: round;
  }

.annotation.badge path.subject-ring {
    fill: white;
    stroke-width: 3px;
  }

.annotation.badge .badge-text {
    fill: white;
    font-size: .7em;
  }

text.hover {
    font-size: 1em;
    fill: black;
    font-weight: bold;
    stroke: green;
  }
  </style>
</head>

<body>
  <script>
		// Source: https://www.eia.gov/outlooks/steo/realprices/
    var margin = {top: 20, right: 50, bottom: 30, left: 50},
        width = 960 - margin.left - margin.right,
        height = 500 - margin.top - margin.bottom

var parseTime = d3.timeParse("%B %Y"),
        formatTime = d3.timeFormat("%b %Y"),
        bisectDate = d3.bisector(function(d) {return d.Month;}).left,
        formatValue = d3.format(",.2f"),
        formatCurrency = function(d){ return "$" + formatValue(d)};

var svg = d3.select("body").append("svg")
        .attr("width", width + margin.left + margin.right)
        .attr("height", height + margin.top + margin.bottom)
      .append("g")
        .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var x = d3.scaleTime()
      .range([0, width]);

var y = d3.scaleLinear()
      .range([height, 0]);

var line = d3.line()
      .x(function(d) { return x(d.Month); })
      .y(function(d) { return y(d.Real_Imported_Crude_Oil_Price); });

d3.csv("real_oil_prices.csv", function(d){
      d.Month = parseTime(d.Month);
      d.Real_Imported_Crude_Oil_Price = parseInt(d.Real_Imported_Crude_Oil_Price);
      d.Nominal_Imported_Crude_Oil_Price = parseInt(d.Nominal_Imported_Crude_Oil_Price);
      return d;
    }, function(error, data) {
        console.log(data);
        x.domain(d3.extent(data, function(d) { return d.Month; }));
        y.domain(d3.extent(data, function(d) { return d.Real_Imported_Crude_Oil_Price; }));

svg.append("g")
       .attr("transform", "translate(0," + height + ")")
       .call(d3.axisBottom(x))
       .select(".domain")
       .remove();

svg.append("g")
         .call(d3.axisLeft(y))
         .append("text")
           .attr("fill", "#000")
           .attr("transform", "rotate(-90)")
           .attr("y", 6)
           .attr("dy", "0.71em")
           .attr("text-anchor", "end")
           .text("Real Imported Crude Oil Price ($)");

svg.append("path")
         .datum(data)
         .attr("fill", "none")
         .attr("stroke", "steelblue")
         .attr("stroke-linejoin", "round")
         .attr("stroke-linecap", "round")
         .attr("stroke-width", 1.5)
         .attr("d", line);

var focus = svg.append("g")
          .attr("class", "focus")
          .style("display", "none");

focus.append("line")
            .attr("class", "x-hover-line hover-line")
            .attr("y1", 0)
            .attr("y2", height);

focus.append("line")
            .attr("class", "y-hover-line hover-line")
            .attr("x1", width)
            .attr("x2", width);

focus.append("circle")
            .attr("r", 4.5);

focus.append("text")
            .attr("x", 9)
            .attr("dy", ".31em");

svg.append("rect")
            .attr("class", "overlay")
            .attr("width", width)
            .attr("height", height)
            .on("mouseover", function() { focus.style("display", null); })
            .on("mouseout", function() { focus.style("display", "none"); })
            .on("mousemove", mousemove);

function mousemove() {
       var x0 = x.invert(d3.mouse(this)[0]),
           i = bisectDate(data, x0, 1),
           d0 = data[i - 1],
           d1 = data[i],
           d = x0 - d0.date > d1.date - x0 ? d1 : d0;
       focus.attr("transform", "translate(" + x(d.Month) + "," + y(d.Real_Imported_Crude_Oil_Price) + ")");
       focus.select("text").text(formatCurrency(d.Real_Imported_Crude_Oil_Price) + " " + formatTime(d.Month));
       focus.select(".x-hover-line").attr("y2", height - y(d.Real_Imported_Crude_Oil_Price));
       focus.select(".y-hover-line").attr("x2", width + width)
     }

const annotations = [
          {
            type: d3.annotationLabel,
            note: {
              label: "Iraq invades Kuwait. Kuwaiti exports cut until 1994",
              title: "1991 Gulf War",
              wrap: 140
            },
            x: 372,
            y: 302,
            dy: -20,
            dx: 20
          },{
            //below in makeAnnotations has type set to d3.annotationLabel
            //you can add this type value below to override that default
            type: d3.annotationCalloutCircle,
            note: {
              label: "Exports from region slow; U.S. flags oil tankers to protect flow of oil in Persian Gulf.",
              title: "1980-88 Iran-Iraq War",
              wrap: 150
            },
            //settings for the subject, in this case the circle radius
            subject: {
              radius: 110
            },
            x: 208,
            y: 227,
            dy: -90,
            dx: 150
          },
          {
            type: d3.annotationLabel,
            note: {
              title: "2001 - 2003",
              label: "9/11 and the invasion of Iraq. Venezuelan oil workers strike",
              wrap: 140
            },
            x: 550,
            y: 280
          },
          {
            type: d3.annotationLabel,
            note: {
              title: "2007-2008 Global Financial Crisis",
              wrap: 150
            },
            x: 720,
            y: 381,
            dy: 20,
            dx: 0
          },
          {
            type: d3.annotationLabel,
            note: {
              title: "Mid-2000s",
              label: "Asia drives rising demand as production stagnates and Saudi spare capacity declines",
              wrap: 140
            },
            x: 635,
            y: 40,
          },
          {
            type: d3.annotationLabel,
            note: {
              title: "2011 Arab Spring",
              label: "Civil war disrupts Libyan output",
              wrap: 150
            },
            x: 820,
            y: 20,
          },
          {
              type: d3.annotationBadge,
              //can use x, y directly instead of data
              // data: { Month: parseTime("June 1980"), Real_Imported_Crude_Oil_Price: 102.5125925 },
              note: {
                title: "1980 Energy Security Act",
                label: "",
                wrap: 150
              },
              x: 170,
              y: 160,
              dy: 137,
              dx: 162,
              subject: {
               text: "A",
               radius: 14
             }
          },
          {
              type: d3.annotationBadge,
              //can use x, y directly instead of data
              // data: { Month: parseTime("June 1980"), Real_Imported_Crude_Oil_Price: 102.5125925 },
              note: {
                title: "1992 Energy Security Act",
                label: "",
                wrap: 150
              },
              x: 407,
              y: 397,
              dy: 400,
              dx: 400,
              subject: {
               text: "B",
               radius: 14,
               y: "top",
               x: "right"
             }
          }, {
              type: d3.annotationBadge,
              //can use x, y directly instead of data
              // data: { Month: parseTime("June 1980"), Real_Imported_Crude_Oil_Price: 102.5125925 },
              note: {
                title: "2005 Energy Security Act",
                label: "",
                wrap: 150
              },
              x: 650,
              y: 295,
              dy: 400,
              dx: 400,
              subject: {
               text: "C",
               radius: 14
             }
           },
           {
               type: d3.annotationBadge,
               //can use x, y directly instead of data
               // data: { Month: parseTime("June 1980"), Real_Imported_Crude_Oil_Price: 102.5125925 },
               note: {
                 title: "2007 Energy Independence and Security Act",
                 label: "",
                 wrap: 150
               },
               x: 695,
               y: 180,
               dy: 400,
               dx: 400,
               subject: {
                text: "D",
                radius: 14,
                y: "bottom"
              }
            }, {
               type: d3.annotationBadge,
               //can use x, y directly instead of data
               // data: { Month: parseTime("June 1980"), Real_Imported_Crude_Oil_Price: 102.5125925 },
               note: {
                 title: "2008 Energy and Tax Extenders Act",
                 label: "",
                 wrap: 150
               },
               x: 715,
               y: 260,
               dy: 400,
               dx: 400,
               subject: {
                text: "E",
                radius: 14,
                y: "bottom"
              }
            },
            {
               type: d3.annotationBadge,
               note: {
                 title: "2009 American Recovery and Reinvestment Act",
                 label: "",
                 wrap: 150
               },
               x: 725,
               y: 355,
               dy: 400,
               dx: 400,
               subject: {
                text: "F",
                radius: 14,
                y: "bottom",
                x: "right"
              }
            }
        ]
        // const type = d3.annotationBadge;
        // const makeAnnotations = d3.annotation()
        //       .type(type)
        //       //accessors & accessorsInverse not needed
        //       //if using x, y in annotations JSON
        //       .accessors({
        //         x: d => x(d.Month),
        //         y: d => y(d.Real_Imported_Crude_Oil_Price)
        //       })
        //       .accessorsInverse({
        //          Month: d => formatTime(x.invert(d.x)),
        //          Real_Imported_Crude_Oil_Price: d => y.invert(d.y)
        //       })
        //       .annotations(annotations)

const makeAnnotations = d3.annotation()
          .annotations(annotations)
          .on('subjectover', function (annotation) {

//cannot reference this if you are using es6 function syntax
            this.append('text')
                .attr('class', 'hover')
                .text(annotation.note.title)
                .attr('text-anchor', 'middle')
                .attr('y', annotation.subject.y && annotation.subject.y == "bottom" ? 50 : -40)
                .attr('x', -15);

this.append('text')
                .attr('class', 'hover')
                .text(annotation.note.label)
                .attr('text-anchor', 'middle')
                .attr('y', annotation.subject.y && annotation.subject.y == "bottom" ? 70 : -60)
                .attr('x', -15);
          }).on('subjectout', function (annotation) {
            this.selectAll('text.hover').remove();
          });

d3.select("svg")
            .append("g")
            .attr("class", "annotation-group")
            .call(makeAnnotations)
    });

</script>
</body>

https://d3js.org/d3.v4.min.js

https://cdnjs.cloudflare.com/ajax/libs/d3-annotation/1.12.1/d3-annotation.min.js