import type { IcsCalendar, IcsEvent } from "ts-ics";
import { isPlanningUrl } from "./url";

type WorkEvent = {
  day: number;
  start: { hours: number; minutes: number };
  end: { hours: number; minutes: number };
};

const makeIcsEvent = (
  data: {
    year: number;
    month: number;
  } & WorkEvent,
): IcsEvent => ({
  uid: `${data.year}-${data.month}-${data.day}-work@aphp-gestime-exporter`,
  summary: "Travail",
  stamp: { date: new Date() },
  start: {
    // - 1 because Date takes month index, e.g 0-11
    date: new Date(
      data.year,
      data.month - 1,
      data.day,
      data.start.hours,
      data.start.minutes,
    ),
  },
  duration: {
    hours: Math.floor(
      (data.end.hours * 60 +
        data.end.minutes -
        (data.start.hours * 60 + data.start.minutes)) /
        60,
    ),
    minutes:
      (data.end.hours * 60 +
        data.end.minutes -
        (data.start.hours * 60 + data.start.minutes)) %
      60,
  },
  location: "Hôpital Pitié-Salpêtrière",
});

const makeIcsCalendar = (events: IcsEvent[]): IcsCalendar => ({
  version: "2.0",
  prodId: "-//pihkaal//Gestime APHP Export//FR",
  events,
});

const dataExtractor = () => {
  // extract year and month
  const monthSelect = document.getElementById(
    "select-pagemois",
  ) as HTMLSelectElement;
  const yearSelect = document.getElementById(
    "select-pagean",
  ) as HTMLSelectElement;

  // extract events
  const trs = document.querySelectorAll("#clearfix-individuel table tr");

  const events: WorkEvent[] = [];

  // [Sam 01, RH]
  // [Dim 02, 7:00 - 19:00]
  for (const tr of trs) {
    const tds = tr.querySelectorAll("td");

    const dateText = tds[0]?.textContent?.trim() ?? "";
    const dateMatch = dateText.match(/^[A-Z][a-z]{2}\s+(\d{2})$/);
    if (!dateMatch) continue;

    const workText = tds[1]?.textContent?.trim() ?? "";
    const hoursMatch = workText.match(/^(\d+):(\d+) - (\d+):(\d+)$/);
    if (!hoursMatch) continue;

    events.push({
      day: parseInt(dateMatch[1]!),
      start: {
        hours: parseInt(hoursMatch[1]!),
        minutes: parseInt(hoursMatch[2]!),
      },
      end: {
        hours: parseInt(hoursMatch[3]!),
        minutes: parseInt(hoursMatch[4]!),
      },
    });
  }

  return {
    month: parseInt(monthSelect.value),
    year: parseInt(yearSelect.value),
    events,
  };
};

export async function extractData(): Promise<{
  name: string;
  data: IcsCalendar;
}> {
  const [tab] = await chrome.tabs.query({
    active: true,
    currentWindow: true,
  });
  if (!tab?.id || !(await isPlanningUrl())) {
    throw new Error("URL incorrecte");
  }

  try {
    const [query] = await chrome.scripting.executeScript({
      target: { tabId: tab.id },
      func: dataExtractor,
    });
    if (!query?.result) throw undefined;

    const { year, month, events } = query.result;

    return {
      name: `gestime-${year}-${month}.ics`,
      data: makeIcsCalendar(
        events.map((event) => makeIcsEvent({ year, month, ...event })),
      ),
    };
  } catch {
    throw new Error(
      "Impossible d'extraires les données, contactez `hello@pihkaal.me`",
    );
  }
}