import fetch from "node-fetch";
import { formatParams, Options } from "./formatParams";

/**
 * get the contribution grid from a github user page
 *
 * use options.from=YYYY-MM-DD options.to=YYYY-MM-DD to get the contribution grid for a specific time range
 * or year=2019 as an alias for from=2019-01-01 to=2019-12-31
 *
 * otherwise return use the time range from today minus one year to today ( as seen in github profile page )
 *
 * @param userName github user name
 * @param options
 *
 * @example
 *  getGithubUserContribution("platane", { from: "2019-01-01", to: "2019-12-31" })
 *  getGithubUserContribution("platane", { year: 2019 })
 *
 */
export const getGithubUserContribution = async (
  userName: string,
  options: Options = {}
) => {
  // either use github.com/users/xxxx/contributions  for previous years
  // or github.com/xxxx ( which gives the latest update to today result )
  const url =
    "year" in options || "from" in options || "to" in options
      ? `https://github.com/users/${userName}/contributions?` +
        formatParams(options)
      : `https://github.com/${userName}`;

  const res = await fetch(url);

  if (!res.ok) throw new Error(res.statusText);

  const resText = await res.text();

  return parseUserPage(resText);
};

const parseUserPage = (content: string) => {
  // take roughly the svg block
  const block = content
    .split(`class="js-calendar-graph-svg"`)[1]
    .split("</svg>")[0];

  let x = 0;
  let lastYAttribute = 0;

  const rects = Array.from(block.matchAll(/<rect[^>]*>/g)).map(([m]) => {
    const date = m.match(/data-date="([^"]+)"/)![1];
    const count = +m.match(/data-count="([^"]+)"/)![1];
    const level = +m.match(/data-level="([^"]+)"/)![1];
    const yAttribute = +m.match(/y="([^"]+)"/)![1];

    if (lastYAttribute > yAttribute) x++;

    lastYAttribute = yAttribute;

    return { date, count, level, x, yAttribute };
  });

  const yAttributes = Array.from(
    new Set(rects.map((c) => c.yAttribute)).keys()
  ).sort();

  const cells = rects.map(({ yAttribute, ...c }) => ({
    y: yAttributes.indexOf(yAttribute),
    ...c,
  }));

  return cells;
};

export type Res = Awaited<ReturnType<typeof getGithubUserContribution>>;

export type Cell = Res[number];