import { select } from "d3-selection";

const BAR_HEIGHT = 30;
const BAR_GAP = 5;

// Select, bind data, join
select(svgElement)
  .selectAll<SVGRectElement, number>("rect")
  .data(values, (d) => String(d)) // key function for identity
  .join("rect") // enter + update merged
  .attr("y", (_, i) => i * (BAR_HEIGHT + BAR_GAP))
  .attr("width", (d) => xScale(d))
  .attr("height", BAR_HEIGHT);

import { scaleLinear, scaleBand, scaleTime, scaleOrdinal } from "d3-scale";

const CHART_WIDTH = 600;
const CHART_HEIGHT = 400;

// Continuous: numbers -> pixels
const x = scaleLinear<number>()
  .domain([0, max(data, (d) => d.value)!])
  .range([0, CHART_WIDTH]);

// Categorical: strings -> pixel bands (bar charts)
const y = scaleBand<string>()
  .domain(data.map((d) => d.label))
  .range([0, CHART_HEIGHT])
  .padding(0.1);

// Time: Date -> pixels
const timeScale = scaleTime<number>()
  .domain([startDate, endDate])
  .range([0, CHART_WIDTH]);

import { axisBottom, axisLeft } from "d3-axis";
import { format } from "d3-format";

const TICK_COUNT = 5;

// Create axes from scales
const xAxis = axisBottom(xScale).ticks(TICK_COUNT).tickFormat(format(",.0f"));
const yAxis = axisLeft(yScale);

// Render into <g> containers
svg
  .append("g")
  .attr("transform", `translate(0,${CHART_HEIGHT - MARGIN_BOTTOM})`)
  .call(xAxis);

svg.append("g").attr("transform", `translate(${MARGIN_LEFT},0)`).call(yAxis);

import { line, area, arc, pie, curveMonotoneX } from "d3-shape";
import type { PieArcDatum } from "d3-shape";

// Line generator
const lineGen = line<DataPoint>()
  .x((d) => xScale(d.date))
  .y((d) => yScale(d.value))
  .curve(curveMonotoneX);

svg
  .append("path")
  .datum(data)
  .attr("d", lineGen)
  .attr("fill", "none")
  .attr("stroke", "steelblue");

// Pie + arc generators
const INNER_RADIUS = 0;
const OUTER_RADIUS = 150;

const pieGen = pie<SliceData>().value((d) => d.value);
const arcGen = arc<PieArcDatum<SliceData>>()
  .innerRadius(INNER_RADIUS)
  .outerRadius(OUTER_RADIUS);

svg
  .selectAll("path")
  .data(pieGen(sliceData))
  .join("path")
  .attr("d", arcGen)
  .attr("fill", (d) => colorScale(d.data.label));

const VIEWBOX_WIDTH = 960;
const VIEWBOX_HEIGHT = 500;

const svg = select(container)
  .append("svg")
  .attr("viewBox", `0 0 ${VIEWBOX_WIDTH} ${VIEWBOX_HEIGHT}`)
  .attr("preserveAspectRatio", "xMidYMid meet")
  .style("width", "100%")
  .style("height", "auto");

import { transition } from "d3-transition";
import { easeCubicOut } from "d3-ease";

const TRANSITION_DURATION_MS = 750;
const STAGGER_DELAY_MS = 50;

select(svgElement)
  .selectAll<SVGRectElement, DataPoint>("rect")
  .data(newData, (d) => d.id)
  .join(
    (enter) =>
      enter
        .append("rect")
        .attr("width", 0)
        .call((s) =>
          s
            .transition()
            .duration(TRANSITION_DURATION_MS)
            .attr("width", (d) => xScale(d.value)),
        ),
    (update) =>
      update.call((s) =>
        s
          .transition()
          .duration(TRANSITION_DURATION_MS)
          .attr("width", (d) => xScale(d.value)),
      ),
    (exit) =>
      exit.call((s) =>
        s
          .transition()
          .duration(TRANSITION_DURATION_MS)
          .attr("width", 0)
          .remove(),
      ),
  );

import { zoom, zoomIdentity } from "d3-zoom";
import type { D3ZoomEvent } from "d3-zoom";

const MIN_ZOOM = 0.5;
const MAX_ZOOM = 32;

const zoomBehavior = zoom<SVGSVGElement, unknown>()
  .scaleExtent([MIN_ZOOM, MAX_ZOOM])
  .on("zoom", (event: D3ZoomEvent<SVGSVGElement, unknown>) => {
    chartGroup.attr("transform", event.transform.toString());
  });

svg.call(zoomBehavior);

import {
  forceSimulation,
  forceLink,
  forceManyBody,
  forceCenter,
  forceCollide,
} from "d3-force";

const CHARGE_STRENGTH = -300;
const COLLISION_RADIUS = 5;

const simulation = forceSimulation(nodes)
  .force(
    "link",
    forceLink(links)
      .id((d: NodeDatum) => d.id)
      .distance(100),
  )
  .force("charge", forceManyBody().strength(CHARGE_STRENGTH))
  .force("center", forceCenter(width / 2, height / 2))
  .force("collide", forceCollide(COLLISION_RADIUS))
  .on("tick", () => {
    // Update node and link positions from simulation
  });

import { geoMercator, geoPath, geoNaturalEarth1 } from "d3-geo";
import type { GeoPermissibleObjects } from "d3-geo";

const projection = geoNaturalEarth1().fitSize(
  [CHART_WIDTH, CHART_HEIGHT],
  geoJsonData,
);

const pathGenerator = geoPath().projection(projection);

svg
  .selectAll("path")
  .data(geoJsonData.features)
  .join("path")
  .attr("d", pathGenerator)
  .attr("fill", (d) => colorScale(dataByRegion.get(d.properties.id) ?? 0));

// Pattern: D3 for computation, framework for rendering
// In your component:

const xScale = scaleLinear().domain([0, maxValue]).range([0, width]);
const yScale = scaleBand().domain(labels).range([0, height]).padding(0.1);
const linePath = line<DataPoint>()
  .x((d) => xScale(d.x))
  .y((d) => yScale(d.y)!)(data);

// Your framework renders SVG with computed values
// <svg><path d={linePath} /><rect width={xScale(d.value)} /></svg>

What are you building?
|
+-> Bar/line/area chart?
|   -> d3-selection, d3-scale, d3-axis, d3-shape, d3-array
|
+-> Pie/donut chart?
|   -> d3-shape (pie + arc generators), d3-scale (color)
|
+-> Force-directed graph?
|   -> d3-force, d3-selection, d3-drag
|
+-> Geographic map?
|   -> d3-geo, d3-selection, d3-scale (color)
|
+-> Animated transitions?
|   -> d3-transition, d3-ease, d3-interpolate
|
+-> Interactive (zoom/brush)?
    -> d3-zoom or d3-brush, d3-selection

Does the visualization need zoom, brush, drag, or force tick?
|
+-> NO -> D3 for computation only (scales, shapes, layouts)
|         Your framework renders SVG/HTML directly
|         Cleanest integration, fully declarative
|
+-> YES -> D3 owns the SVG via a ref element
           Call D3 in a lifecycle hook (mount/update)
           Clean up behaviors on unmount