import { lab, rgb } from "d3-color";
import * as d3Scale from "d3-scale-chromatic";
import React from "react";
import StandardCssColors from "../../Core/StandardCssColors";
import { OptionRenderer } from "../../Models/SelectableDimensions/SelectableDimensions";

/* The ramp and swatches functions are adapted from https://observablehq.com/@d3/color-schemes?collection=@d3/d3-scale-chromatic
 *
 * Copyright 2018–2020 Observable, Inc.
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

const interpolateWidth = 300;
const height = 20;

function ramp(
  name: string | undefined,
  n: number | undefined
): React.ReactChild {
  if (!name) return <span>Invalid</span>;
  let colors: string[];

  /** This could be used to draw text on top of swatches/ramps */
  let dark;
  if (
    n &&
    (d3Scale as any)[`scheme${name}`] &&
    (d3Scale as any)[`scheme${name}`][n]
  ) {
    colors = (d3Scale as any)[`scheme${name}`][n];
    dark = lab(colors[0]).l < 50;
  } else {
    const interpolate = (d3Scale as any)[`interpolate${name}`];
    if (!interpolate) {
      return <span>Invalid</span>;
    }
    colors = [];
    dark = lab(interpolate(0)).l < 50;
    for (let i = 0; i < interpolateWidth; ++i) {
      colors.push(rgb(interpolate(i / (interpolateWidth - 1))).hex());
    }
  }
  if (n && n < 14) {
    return (
      <svg
        viewBox={`0 0 ${n} 1`}
        preserveAspectRatio="none"
        style={{
          display: "block",
          shapeRendering: "crispEdges",
          height: `${height}px`,
          maxWidth: "100%"
        }}
      >
        {colors.map((c, i) => (
          <rect key={i} x={i} width={1} height={1} fill={c} />
        ))}
      </svg>
    );
  } else {
    const canvas = document.createElement("canvas");
    canvas.width = interpolateWidth;
    canvas.height = 1;
    const context = canvas.getContext("2d");
    if (!context) return <span>Invalid</span>;
    canvas.style.width = `${interpolateWidth}px`;
    canvas.style.height = `${height}px`;
    for (let i = 0; i < interpolateWidth; ++i) {
      context.fillStyle = colors[i];
      context.fillRect(i, 0, 1, 1);
    }

    return (
      <div style={{ marginTop: "5px" }}>
        <img
          style={{
            height: `${height}px`,
            width: "100%",
            imageRendering: "crisp-edges"
          }}
          src={canvas.toDataURL("image/jpeg", 1.0)}
        />
      </div>
    );
  }
}

function swatches(name: string | undefined) {
  if (!name) return <span>Invalid</span>;
  let colors: string[] | undefined = (d3Scale as any)[`scheme${name}`];
  // Handle custom HighContrast style
  if (!colors && name === "HighContrast") {
    colors = StandardCssColors.highContrast;
  }
  if (!colors) return <span>Invalid</span>;
  const n = colors.length;
  const dark = lab(colors[0]).l < 50;
  return (
    <svg
      viewBox={`0 0 ${n} 1`}
      preserveAspectRatio="none"
      style={{
        display: "block",
        shapeRendering: "crispEdges",
        height: `${height}px`,
        maxWidth: "100%"
      }}
    >
      {colors.map((c, i) => (
        <rect key={i} x={i} width={1} height={1} fill={c} />
      ))}
    </svg>
  );
}

/** numBins = undefined - indicates continuous color scheme */
export const QuantitativeColorSchemeOptionRenderer: (
  numBins: number | undefined
) => OptionRenderer = (numBins) => (option) => ramp(option.value, numBins);

export const QualitativeColorSchemeOptionRenderer: OptionRenderer = (option) =>
  swatches(option.value);