import { useCallback, useEffect, useRef, useState } from "react";
import { useAppSelector } from "../store";
import { locationService } from "../services";
import { DAILY_TIMESTAMP } from "../helpers/consts";
import * as utils from "../helpers/utils";
import "../less/usage-heat-map.less";

const tableConfig = {
  width: 12,
  height: 7,
};

const getInitialUsageStat = (usedDaysAmount: number, beginDayTimestemp: number): DailyUsageStat[] => {
  const initialUsageStat: DailyUsageStat[] = [];
  for (let i = 1; i <= usedDaysAmount; i++) {
    initialUsageStat.push({
      timestamp: beginDayTimestemp + DAILY_TIMESTAMP * i,
      count: 0,
    });
  }
  return initialUsageStat;
};

interface DailyUsageStat {
  timestamp: number;
  count: number;
}

interface Props {}

const UsageHeatMap: React.FC<Props> = () => {
  const todayTimeStamp = utils.getDateStampByDate(Date.now());
  const todayDay = new Date(todayTimeStamp).getDay() + 1;
  const nullCell = new Array(7 - todayDay).fill(0);
  const usedDaysAmount = (tableConfig.width - 1) * tableConfig.height + todayDay;
  const beginDayTimestemp = todayTimeStamp - usedDaysAmount * DAILY_TIMESTAMP;

  const { memos } = useAppSelector((state) => state.memo);
  const [allStat, setAllStat] = useState<DailyUsageStat[]>(getInitialUsageStat(usedDaysAmount, beginDayTimestemp));
  const [popupStat, setPopupStat] = useState<DailyUsageStat | null>(null);
  const [currentStat, setCurrentStat] = useState<DailyUsageStat | null>(null);
  const containerElRef = useRef<HTMLDivElement>(null);
  const popupRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    const newStat: DailyUsageStat[] = getInitialUsageStat(usedDaysAmount, beginDayTimestemp);
    for (const m of memos) {
      const index = (utils.getDateStampByDate(m.createdTs) - beginDayTimestemp) / (1000 * 3600 * 24) - 1;
      if (index >= 0) {
        newStat[index].count += 1;
      }
    }
    setAllStat([...newStat]);
  }, [memos]);

  const handleUsageStatItemMouseEnter = useCallback((event: React.MouseEvent, item: DailyUsageStat) => {
    setPopupStat(item);
    if (!popupRef.current) {
      return;
    }

    const targetEl = event.target as HTMLElement;
    popupRef.current.style.left = targetEl.offsetLeft + "px";
    popupRef.current.style.top = targetEl.offsetTop - 4 + "px";
  }, []);

  const handleUsageStatItemMouseLeave = useCallback(() => {
    setPopupStat(null);
  }, []);

  const handleUsageStatItemClick = useCallback((item: DailyUsageStat) => {
    if (locationService.getState().query?.duration?.from === item.timestamp) {
      locationService.setFromAndToQuery();
      setCurrentStat(null);
    } else if (item.count > 0) {
      if (!["/"].includes(locationService.getState().pathname)) {
        locationService.setPathname("/");
      }
      locationService.setFromAndToQuery(item.timestamp, item.timestamp + DAILY_TIMESTAMP);
      setCurrentStat(item);
    }
  }, []);

  return (
    <div className="usage-heat-map-wrapper" ref={containerElRef}>
      <div className="day-tip-text-container">
        <span className="tip-text">Sun</span>
        <span className="tip-text"></span>
        <span className="tip-text">Tue</span>
        <span className="tip-text"></span>
        <span className="tip-text">Thu</span>
        <span className="tip-text"></span>
        <span className="tip-text">Sat</span>
      </div>

      <div ref={popupRef} className={"usage-detail-container pop-up " + (popupStat ? "" : "hidden")}>
        {popupStat?.count} memos on <span className="date-text">{new Date(popupStat?.timestamp as number).toDateString()}</span>
      </div>

      <div className="usage-heat-map">
        {allStat.map((v, i) => {
          const count = v.count;
          const colorLevel =
            count <= 0
              ? ""
              : count <= 1
              ? "stat-day-L1-bg"
              : count <= 2
              ? "stat-day-L2-bg"
              : count <= 4
              ? "stat-day-L3-bg"
              : "stat-day-L4-bg";

          return (
            <span
              className={`stat-container ${colorLevel} ${currentStat === v ? "current" : ""} ${
                todayTimeStamp === v.timestamp ? "today" : ""
              }`}
              key={i}
              onMouseEnter={(e) => handleUsageStatItemMouseEnter(e, v)}
              onMouseLeave={handleUsageStatItemMouseLeave}
              onClick={() => handleUsageStatItemClick(v)}
            ></span>
          );
        })}
        {nullCell.map((_, i) => (
          <span className="stat-container null" key={i}></span>
        ))}
      </div>
    </div>
  );
};

export default UsageHeatMap;
