{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "name": "SavingsGoals",
  "title": {
    "text": "Savings goals",
    "subtitle": "Percentage of revenues put into savings, averaged over the last half year"
  },
  "width": "container",
  "height": "container",
  "data": { "url": "../charts/savings.csv"},

  "transform": [
    {
      "window": [{"op": "sum", "field": "value", "as": "rolling_sum"}],
      "groupby": ["account"],
      "frame": [-181, 0]
    },
    {
      "window": [{"op": "count", "as": "window_size"}],
      "groupby": ["account"],
      "frame": [-181, 0]
    },
    { "filter": "datum.window_size >= 90" },
    { "pivot": "account", "groupby": ["end_date"], "value": "rolling_sum" },
    {
      "calculate": "datum.revenuesuper != 0 ? (datum.revenuesuper - datum.expenses) / datum.revenuesuper : 0",
      "as": "Including superannuation"
    },
    {
      "calculate": "datum.revenue != 0 ? (datum.revenue - datum.expenses) / datum.revenue : 0",
      "as": "Savings"
    },
    {
      "calculate": "datum.revenue != 0 ? (datum.revenue - datum.repayments) / datum.revenue : 0",
      "as": "Liquid savings"
    },
    {"fold": ["Savings", "Liquid savings", "Including superannuation"], "as": ["account", "value"]},
    {"calculate": "datum.value * 100", "as": "percentage"}
  ],

  "layer": [
    {
      "encoding": {
        "x": {
          "field": "end_date",
          "title": null,
          "type": "temporal",
          "scale": { "domainMin": { "expr": "timeOffset('year', now(), -1)" } }
        },
        "y": {
          "field": "percentage",
          "title": null,
          "type": "quantitative"
        },
        "color": {
          "field": "account",
          "type": "nominal",
          "legend": { "title": null, "orient": "bottom" }
        }
      },
      "layer": [
        {
          "mark": "line",
          "params": [{ "name": "grid", "select": "interval", "bind": "scales" }]
        },{
          "params": [{
            "name": "label",
            "select": { "type": "point", "encodings": ["x"], "nearest": true, "on": "mouseover" }
          }],
          "mark": "point",
          "encoding": { "opacity": { "condition": { "param": "label", "empty": false, "value": 1 }, "value": 0 } }
        }
      ]
    },{
      "transform": [{"filter": {"param": "label", "empty": false}}],
      "layer": [
        {
          "mark": {"type": "rule", "color": "gray"},
          "encoding": {
            "x": {"type": "temporal", "field": "end_date", "aggregate": "min"}
          }
        },{
          "encoding": {
            "text": {"type": "quantitative", "field": "value", "aggregate": "sum", "format": "0.1%"},
            "x": {"type": "temporal", "field": "end_date"},
            "y": {"type": "quantitative", "field": "percentage", "aggregate": "sum"},
            "color": {"type": "nominal", "field": "account"}
          },
          "layer": [
            { "mark": {"type": "text", "align": "right", "dx": -5, "dy": -5, "strokeWidth": 2, "stroke": "white"} },
            { "mark": {"type": "text", "align": "right", "dx": -5, "dy": -5} }
          ]
        }
      ]
    }
  ]
}