import {
  format,
  formatDistanceToNowStrict,
  differenceInDays,
  isToday,
  isYesterday,
  startOfDay,
  startOfMonth,
  startOfWeek,
  startOfYear,
} from "date-fns";

export function formatTime(date: Date) {
  return format(date, "p");
}

export function formatTime24Hours(date: Date) {
  return format(date, "HH:mm");
}

export function getAbbreviateMonth(date: Date) {
  return format(date, "LLL");
}

export function getDayOfMonth(date: Date) {
  return date.getDate();
}

export function getAgo(date: Date, addSuffix = true) {
  return formatDistanceToNowStrict(date, { addSuffix });
}

type GetDisplayDateBasedOnDurationOptions = {
  yesterdayRelative?: boolean;
};

export function getDisplayDateBasedOnDuration(
  date: Date,
  { yesterdayRelative = true }: GetDisplayDateBasedOnDurationOptions = {},
) {
  if (isToday(date)) {
    return getAgo(date);
  }

  if (isYesterday(date)) {
    return yesterdayRelative ? getAgo(date) : format(date, "p");
  }

  return format(date, "PPPp");
}

type DateGroup = "today" | "yesterday" | "lastWeek" | "lastMonth" | number;

export const categorizeItemsByDate = <
  T extends Record<D, Date>,
  D extends keyof T,
>(
  items: T[],
  dateField: D,
) => {
  const groups: Record<DateGroup, T[]> = {
    today: [],
    yesterday: [],
    lastWeek: [],
    lastMonth: [],
  };

  items.forEach((item) => {
    const date = item[dateField];

    const diffDays = Math.abs(differenceInDays(date, new Date()));

    if (isToday(date)) {
      groups.today.push(item);
    } else if (isYesterday(date)) {
      groups.yesterday.push(item);
    } else if (diffDays <= 7) {
      groups.lastWeek.push(item);
    } else if (diffDays <= 30) {
      groups.lastMonth.push(item);
    } else {
      groups[date.getFullYear()].push(item);
    }
  });

  return groups;
};

export type DateGranularity = "day" | "week" | "month" | "year";
const dateGranularityFunction: Record<DateGranularity, (date: Date) => Date> = {
  day: startOfDay,
  month: startOfMonth,
  week: startOfWeek,
  year: startOfYear,
};

export function setDateGranularity(date: Date, granularity: DateGranularity) {
  return (
    dateGranularityFunction[granularity]?.(date) ||
    new Error(`Invalid date granularity ${granularity}`)
  );
}