import { differenceInDays, format, formatDistanceToNow, startOfDay, startOfMinute, startOfMonth, startOfWeek, startOfYear } from "date-fns";

export type DateFormatType = "YYYY-MM-DD" | "DD-MM-YYYY" | "MM-DD-YYYY" | "diff";
export const DateFormats: { name: string; value: DateFormatType; labelKey: string }[] = [
  { name: "YYYY-MM-DD", value: "YYYY-MM-DD", labelKey: "formats.date.ymd" },
  { name: "DD-MM-YYYY", value: "DD-MM-YYYY", labelKey: "formats.date.dmy" },
  { name: "MM-DD-YYYY", value: "MM-DD-YYYY", labelKey: "formats.date.mdy" },
  { name: "Difference", value: "diff", labelKey: "formats.date.diff" },
];
export type DateDisplay = "ymd" | "ago" | "dm" | "mdy" | "hms" | "ymdhms" | "ymdhmsms";

const coerce = (value: Date | string | null | undefined): Date => {
  if (value === null || value === undefined) return new Date();
  return value instanceof Date ? value : new Date(value);
};

const fmt = (value: Date | string | null | undefined, pattern: string): string => {
  return format(coerce(value), pattern);
};

const dateAgo = (value: Date | string | null | undefined): string => {
  const at = coerce(value);
  const days = Math.abs(differenceInDays(new Date(), at));
  if (days <= 1) {
    return formatDistanceToNow(startOfMinute(at), { addSuffix: true });
  } else if (days <= 7) {
    return formatDistanceToNow(startOfDay(at), { addSuffix: true });
  } else if (days <= 30) {
    return formatDistanceToNow(startOfWeek(at), { addSuffix: true });
  } else if (days <= 30 * 12) {
    return formatDistanceToNow(startOfMonth(at), { addSuffix: true });
  } else if (days <= 30 * 12 * 2) {
    return formatDistanceToNow(startOfYear(at), { addSuffix: true });
  } else {
    return fmt(at, "yyyy-MM-dd");
  }
};
const dateYMD = (value: Date | string | null | undefined): string => fmt(value, "yyyy-MM-dd");
const dateDMY = (value: Date | string | null | undefined): string => fmt(value, "dd-MM-yyyy");
const dateMDY = (value: Date | string | null | undefined): string => fmt(value, "MM-dd-yyyy");
const dateLL = (value: Date | string | null | undefined): string => fmt(value, "yyyy-MM-dd");
const dateYMDHM = (value: Date | string | null | undefined): string => fmt(value, "yyyy-MM-dd HH:mm");
const dateYMDHMS = (value: Date | string | null | undefined): string => fmt(value, "yyyy-MM-dd HH:mm:ss");
const dateYMDHMSMS = (value: Date | string | null | undefined): string => fmt(value, "yyyy-MM-dd HH:mm:ss.SSS");
const dateMonthName = (value: Date | string | null | undefined): string => fmt(value, "MMMM yyyy");
const dateDM = (value: Date | string | null | undefined): string => fmt(value, "d MMM");
const dateMonthDayYear = (value: Date | string | null | undefined): string => fmt(value, "MMMM d, yyyy");
const dateMonthDay = (value: Date | string | null | undefined): string => fmt(value, "MMM d");
const dateHMS = (value: Date | string | null | undefined): string => fmt(value, "HH:mm:ss");

const daysFromDate = (value: Date, days: number) => {
  return new Date(new Date().setDate(value.getDate() + days));
};

const diffDays = (a: Date, b: Date) => {
  const utc1 = Date.UTC(a.getFullYear(), a.getMonth(), a.getDate());
  const utc2 = Date.UTC(b.getFullYear(), b.getMonth(), b.getDate());

  const _MS_PER_DAY = 1000 * 60 * 60 * 24;
  return (utc2 - utc1) / _MS_PER_DAY;
};

const add = (value: Date, days: number) => {
  return new Date(new Date().setDate(value.getDate() + days));
};

const getMonths = () => {
  return ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
};

const getMonthName = (month: number): string => {
  const months: string[] = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
  if (month >= 1 && month <= 12) {
    return months[month - 1].substring(0, 3);
  }
  return "";
};

const isCurrentMonth = (year: number, month: number): boolean => {
  const today = new Date();
  return today.getFullYear() === year && today.getMonth() + 1 === month;
};

const gteFromFilter = (filter: string, from?: Date) => {
  let gte: Date | undefined = undefined;
  if (!from) {
    from = new Date();
  }

  if (filter === "all-time") {
    gte = undefined;
  } else if (filter === "last-24-hours") {
    gte = daysFromDate(from, 1 * -1);
  } else if (filter === "last-7-days") {
    gte = daysFromDate(from, 7 * -1);
  } else if (filter === "last-30-days") {
    gte = daysFromDate(from, 30 * -1);
  } else if (filter === "last-3-months") {
    gte = daysFromDate(from, 30 * 3 * -1);
  } else if (filter === "last-6-months") {
    gte = daysFromDate(from, 30 * 6 * -1);
  } else if (filter === "last-year") {
    gte = daysFromDate(from, 30 * 12 * -1);
  } else if (filter === "year-to-date") {
    gte = new Date(from.getFullYear(), 0, 1);
  } else if (filter === "month-to-date") {
    gte = new Date(from.getFullYear(), from.getMonth(), 1);
  } else if (filter === "week-to-date") {
    gte = new Date(from.getFullYear(), from.getMonth(), from.getDate() - from.getDay());
  } else if (filter === "last-hour") {
    gte = new Date(from.getTime() - 60 * 60 * 1000);
  } else if (filter === "last-10-minutes") {
    gte = new Date(from.getTime() - 10 * 60 * 1000);
  }
  return gte;
};

const getDuration = ({ start, end, format = "s" }: { start: Date; end: Date; format: "ms" | "s" | "m" | "h" | "d" | "w" | "M" | "y" }) => {
  const diff = +new Date(end) - +new Date(start);
  const seconds = Math.floor(diff / 1000);
  switch (format) {
    case "ms":
      return diff;
    case "s":
      return seconds;
    case "m":
      return Math.floor(seconds / 60);
    case "h":
      return Math.floor(seconds / 3600);
    case "d":
      return Math.floor(seconds / 86400);
    case "w":
      return Math.floor(seconds / 604800);
    case "M":
      return Math.floor(seconds / 2592000);
    case "y":
      return Math.floor(seconds / 31536000);
    default:
      return diff;
  }
};

function getDurationInSeconds({ start, end }: { start: Date | null; end: Date | null }) {
  if (start && end) {
    const diff = +new Date(end) - +new Date(start);
    const seconds = Math.floor(diff / 1000);

    if (seconds < 60) {
      return `${seconds}s`;
    } else {
      return `${Math.floor(seconds / 60)}m ${seconds % 60}s`;
    }
  }
  return "-";
}

function getDateStartOfDay(date: Date) {
  return new Date(date.getFullYear(), date.getMonth(), date.getDate(), 0, 0, 0, 0);
}
function getDateEndOfDay(date: Date) {
  return new Date(date.getFullYear(), date.getMonth(), date.getDate(), 23, 59, 59, 999);
}

export default {
  dateAgo,
  dateYMD,
  dateDMY,
  dateMDY,
  dateLL,
  dateYMDHM,
  dateYMDHMS,
  dateYMDHMSMS,
  dateMonthName,
  dateDM,
  dateHMS,
  dateMonthDayYear,
  dateMonthDay,
  daysFromDate,
  diffDays,
  add,
  getMonths,
  getMonthName,
  isCurrentMonth,
  gteFromFilter,
  getDuration,
  getDurationInSeconds,
  getDateStartOfDay,
  getDateEndOfDay,
};