import process from "node:process";
import dayjs from "@calcom/dayjs";
import type { DateRange } from "@calcom/features/schedules/lib/date-ranges";
import { beforeAll, describe, expect, it, vi } from "vitest";
import getSlots from "./slots";

let dateRangesNextDay: DateRange[];

let dateRangesMockDay: DateRange[];

beforeAll(() => {
  vi.setSystemTime(dayjs.utc("2021-06-20T11:59:59Z").toDate());

  dateRangesMockDay = [{ start: dayjs.utc().startOf("day"), end: dayjs.utc().endOf("day") }];

  dateRangesNextDay = [
    {
      start: dayjs.utc().add(1, "day").startOf("day"),
      end: dayjs.utc().add(1, "day").endOf("day"),
    },
  ];
});

describe("Tests the slot logic", () => {
  it("can fit 24 hourly slots for an empty day", async () => {
    expect(
      getSlots({
        inviteeDate: dayjs.utc().add(1, "day"),
        frequency: 60,
        minimumBookingNotice: 0,
        eventLength: 60,
        dateRanges: dateRangesNextDay,
      })
    ).toHaveLength(24);
  });

  it("can fit 24 hourly slots for an empty day with interval != eventLength", async () => {
    expect(
      getSlots({
        inviteeDate: dayjs.utc().add(1, "day"),
        frequency: 60,
        minimumBookingNotice: 0,
        eventLength: 30,
        dateRanges: dateRangesNextDay,
      })
    ).toHaveLength(24);
  });

  it("only shows future booking slots on the same day", async () => {
    // The mock date is 1s to midday, so 12 slots should be open given 0 booking notice.

    expect(
      getSlots({
        inviteeDate: dayjs.utc(),
        frequency: 60,
        minimumBookingNotice: 0,
        dateRanges: dateRangesMockDay,
        eventLength: 60,
        offsetStart: 0,
      })
    ).toHaveLength(12);
  });

  it("adds minimum booking notice correctly", async () => {
    // 24h in a day.
    expect(
      getSlots({
        inviteeDate: dayjs.utc().add(1, "day").startOf("day"),
        frequency: 60,
        minimumBookingNotice: 1500,
        dateRanges: dateRangesNextDay,
        eventLength: 60,
        offsetStart: 0,
      })
    ).toHaveLength(11);
  });

  it("shows correct time slots for 20 minutes long events with working hours that do not end at a full hour ", async () => {
    // 72 20-minutes events in a 24h day
    const result = getSlots({
      inviteeDate: dayjs().add(1, "day"),
      frequency: 20,
      minimumBookingNotice: 0,
      dateRanges: dateRangesNextDay,
      eventLength: 20,
      offsetStart: 0,
    });
    expect(result).toHaveLength(72);
  });

  it("can create multiple time slot groups when multiple date ranges are given", async () => {
    const nextDay = dayjs.utc().add(1, "day").startOf("day");
    const dateRanges = [
      // 11:00-11:20,11:20-11:40,11:40-12:00
      {
        start: nextDay.hour(11),
        end: nextDay.hour(12),
      },
      // 14:00-14:20,14:20-14:40,14:40-15:00
      {
        start: nextDay.hour(14),
        end: nextDay.hour(15),
      },
    ];
    const result = getSlots({
      inviteeDate: nextDay,
      frequency: 20,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 20,
      offsetStart: 0,
    });

    expect(result).toHaveLength(6);
  });

  it("can merge multiple time slot groups when multiple date ranges are given that overlap", async () => {
    const nextDay = dayjs.utc().add(1, "day").startOf("day");
    const dateRanges = [
      // 11:00-11:20,11:20-11:40,11:40-12:00
      {
        start: nextDay.hour(11),
        end: nextDay.hour(12),
      },
      // 12:00-12:20,12:20-12:40
      {
        start: nextDay.hour(11).minute(20),
        end: nextDay.hour(12).minute(40),
      },
    ];
    const result = getSlots({
      inviteeDate: nextDay,
      frequency: 20,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 20,
      offsetStart: 0,
    });

    expect(result).toHaveLength(5);
  });

  // for now, stay consistent with current behaviour and enable the slot 11:00, 11:45
  // however, optimal slot allocation is 11:15-12:00,12:00-12:45 (as both hosts can be routed to at this time)
  it("finds correct slots when two unequal date ranges are given", async () => {
    const nextDay = dayjs.utc().add(1, "day").startOf("day");
    const dateRanges = [
      // 11:00-13:00
      {
        start: nextDay.hour(11),
        end: nextDay.hour(13),
      },
      // 11:15-13:00
      {
        start: nextDay.hour(11).minute(15),
        end: nextDay.hour(13),
      },
    ];
    const result = getSlots({
      inviteeDate: nextDay,
      frequency: 45,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 45,
      offsetStart: 0,
    });

    expect(result).toHaveLength(2);
  });
  it("finds correct slots when two unequal date ranges are given (inverse)", async () => {
    const nextDay = dayjs.utc().add(1, "day").startOf("day");

    const dateRangesInverseOrder = [
      // 11:15-13:00
      {
        start: nextDay.hour(11).minute(15),
        end: nextDay.hour(13),
      },
      // 11:00-13:00
      {
        start: nextDay.hour(11),
        end: nextDay.hour(13),
      },
    ];

    const resultInverseOrder = getSlots({
      inviteeDate: nextDay,
      frequency: 45,
      minimumBookingNotice: 0,
      dateRanges: dateRangesInverseOrder,
      eventLength: 45,
      offsetStart: 0,
    });

    expect(resultInverseOrder).toHaveLength(2);
  });

  it("finds correct slots over the span of multiple days", async () => {
    const inviteeDate = dayjs.utc().add(1, "day").startOf("day");

    const dateRanges = [
      // 11:30-14:00
      {
        start: inviteeDate.hour(11).minute(30),
        end: inviteeDate.hour(14),
      },
      // 9:15-13:00
      {
        start: inviteeDate.hour(9).minute(15),
        end: inviteeDate.hour(11),
      },
      // 11:30-14:00
      {
        start: inviteeDate.add(1, "day").hour(11).minute(30),
        end: inviteeDate.add(1, "day").hour(14),
      },
      // 11:15-13:00
      {
        start: inviteeDate.add(1, "day").hour(9).minute(15),
        end: inviteeDate.add(1, "day").hour(11),
      },
    ];

    // each day availability should go 10:00, 12:00, 13:00

    const result = getSlots({
      // right now from the perspective of invitee local time.
      inviteeDate,
      frequency: 60,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 60,
      offsetStart: 0,
    });

    expect(result).toHaveLength(6);
  });

  it("shows correct time slots for 20 minutes long events with working hours that do not end at a full hour", async () => {
    const result = getSlots({
      inviteeDate: dayjs().add(1, "day"),
      frequency: 20,
      minimumBookingNotice: 0,
      dateRanges: [{ start: dayjs("2021-06-21T00:00:00.000Z"), end: dayjs("2021-06-21T23:45:00.000Z") }],
      eventLength: 20,
      offsetStart: 0,
    });

    // 71 20-minutes events in a 24h - 15m day
    expect(result).toHaveLength(71);
  });

  it("tests the final slot of the day is included", async () => {
    const slots = getSlots({
      inviteeDate: dayjs.tz("2023-07-13T00:00:00.000", "Europe/Brussels"),
      eventLength: 15,
      offsetStart: 0,
      dateRanges: [
        { start: dayjs("2023-07-13T07:00:00.000Z"), end: dayjs("2023-07-13T15:00:00.000Z") },
        { start: dayjs("2023-07-13T18:30:00.000Z"), end: dayjs("2023-07-13T20:59:59.000Z") },
      ],
      minimumBookingNotice: 120,
      frequency: 15,
    }).reverse();

    expect(slots[0].time.format()).toBe("2023-07-13T22:45:00+02:00");
  });

  it("tests slots for half hour timezones", async () => {
    const slots = getSlots({
      inviteeDate: dayjs.tz("2023-07-13T00:00:00.000", "Asia/Kolkata"),
      frequency: 60,
      minimumBookingNotice: 0,
      eventLength: 60,
      dateRanges: [
        {
          start: dayjs.tz("2023-07-13T07:30:00.000", "Asia/Kolkata"),
          end: dayjs.tz("2023-07-13T09:30:00.000", "Asia/Kolkata"),
        },
      ],
    });

    expect(slots).toHaveLength(1);
    expect(slots[0].time.format()).toBe("2023-07-13T08:00:00+05:30");
  });

  it("tests slots for 5 minute events", async () => {
    const slots = getSlots({
      inviteeDate: dayjs.tz("2023-07-13T00:00:00.000+05:30", "Europe/London"),
      frequency: 5,
      minimumBookingNotice: 0,
      eventLength: 5,
      dateRanges: [
        // fits 1 slot
        {
          start: dayjs.tz("2023-07-13T07:00:00.000", "Europe/London"),
          end: dayjs.tz("2023-07-13T07:05:00.000", "Europe/London"),
        },
        // fits 4 slots
        {
          start: dayjs.tz("2023-07-13T07:10:00.000", "Europe/London"),
          end: dayjs.tz("2023-07-13T07:30:00.000", "Europe/London"),
        },
      ],
    });

    expect(slots).toHaveLength(5);
  });

  it("tests slots for events with an event length that is not divisible by 5", async () => {
    const slots = getSlots({
      inviteeDate: dayjs.utc().startOf("day"),
      frequency: 8,
      minimumBookingNotice: 0,
      eventLength: 8,
      dateRanges: [
        {
          start: dayjs.utc("2023-07-13T07:22:00.000"),
          end: dayjs.utc("2023-07-13T08:00:00.000"),
        },
      ],
    });
    /*
     * 2023-07-13T07:22:00.000Z
     * 2023-07-13T07:30:00.000Z
     * 2023-07-13T07:38:00.000Z
     * 2023-07-13T07:46:00.000Z
     */
    expect(slots).toHaveLength(4);
  });
});

describe("Tests the slot logic with custom env variable", () => {
  beforeAll(() => {
    vi.stubEnv("NEXT_PUBLIC_AVAILABILITY_SCHEDULE_INTERVAL", "10");
  });

  it("test using a 10 minute interval", async () => {
    expect(Number(process.env.NEXT_PUBLIC_AVAILABILITY_SCHEDULE_INTERVAL)).toBe(10);
    expect(
      getSlots({
        inviteeDate: dayjs.utc().add(1, "day"),
        frequency: 10,
        minimumBookingNotice: 0,
        eventLength: 10,
        offsetStart: 0,
        dateRanges: [{ start: dayjs("2023-07-13T00:10:00.000Z"), end: dayjs("2023-07-13T02:00:00.000Z") }],
      })
    ).toHaveLength(11);
  });
});

describe("Tests the slots function performance", () => {
  it("handles hundreds of date ranges efficiently", async () => {
    const startTime = process.hrtime();

    const startDay = dayjs.utc().add(1, "day").startOf("day");
    const dateRanges: DateRange[] = [];

    for (let day = 0; day < 7; day++) {
      const currentDay = startDay.add(day, "day");

      for (let hour = 0; hour < 24; hour++) {
        for (let minute = 0; minute < 60; minute += 5) {
          if (dateRanges.length >= 2000) break;

          dateRanges.push({
            start: currentDay.hour(hour).minute(minute),
            end: currentDay
              .hour(hour)
              .minute(minute + 4)
              .second(59),
          });
        }
        if (dateRanges.length >= 2000) break;
      }
      if (dateRanges.length >= 2000) break;
    }

    const result = getSlots({
      inviteeDate: startDay,
      frequency: 5,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 5,
      offsetStart: 0,
    });

    expect(result.length).toBeGreaterThan(0);

    const endTime = process.hrtime(startTime);
    const executionTimeInMs = endTime[0] * 1000 + endTime[1] / 1000000;

    expect(executionTimeInMs).toBeLessThan(3000); // less than 3 seconds for 2000 date ranges

    console.log(
      `Performance test completed in ${executionTimeInMs}ms with ${result.length} slots generated from ${dateRanges.length} date ranges`
    );
  });
});

describe("Tests the date-range slot logic with showOptimizedSlots", () => {
  it("should respect start of the hour for 60minutes slots for availabilities like 09:30-17:00, when showOptimizedSlots set to true", async () => {
    const slots = getSlots({
      showOptimizedSlots: true,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:09:30, end:17:00
      // with 09:00 - 09:30 busy time
      dateRanges: [{ start: dayjs("2024-09-12T16:30:00.000Z"), end: dayjs("2024-09-13T00:00:00.000Z") }],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T10:00:00-07:00",
      "2024-09-12T11:00:00-07:00",
      "2024-09-12T12:00:00-07:00",
      "2024-09-12T13:00:00-07:00",
      "2024-09-12T14:00:00-07:00",
      "2024-09-12T15:00:00-07:00",
      "2024-09-12T16:00:00-07:00",
    ]);
  });

  it("shows 4 60minutes slots for availability like 08:00-12:30 with 10:00-10:10 busytime, when showOptimizedSlots set to true", async () => {
    const slots = getSlots({
      showOptimizedSlots: true,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:08:00, end:10:00
      // start:10:10, end:12:30
      // with 10:00 - 10:10 busy time
      dateRanges: [
        { start: dayjs("2024-09-12T15:00:00.000Z"), end: dayjs("2024-09-12T17:00:00.000Z") },
        { start: dayjs("2024-09-12T17:10:00.000Z"), end: dayjs("2024-09-12T19:30:00.000Z") },
      ],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T10:15:00-07:00",
      "2024-09-12T11:15:00-07:00",
    ]);
  });

  it("shows 3 60minutes slots for availability like 08:00-12:30 with 10:00-10:10 busytime, when showOptimizedSlots set to false", async () => {
    const slots = getSlots({
      showOptimizedSlots: false,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:08:00, end:10:00
      // start:10:10, end:12:30
      // with 10:00 - 10:10 busy time
      dateRanges: [
        { start: dayjs("2024-09-12T15:00:00.000Z"), end: dayjs("2024-09-12T17:00:00.000Z") },
        { start: dayjs("2024-09-12T17:10:00.000Z"), end: dayjs("2024-09-12T19:30:00.000Z") },
      ],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T11:00:00-07:00",
    ]);
  });

  it("shows 3 60minutes slots for availability like 08:00-12:00 with 10:00-10:10 busytime, when showOptimizedSlots set to true", async () => {
    const slots = getSlots({
      showOptimizedSlots: true,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:08:00, end:10:00
      // start:10:10, end:12:00
      // with 10:00 - 10:10 busy time
      dateRanges: [
        { start: dayjs("2024-09-12T15:00:00.000Z"), end: dayjs("2024-09-12T17:00:00.000Z") },
        { start: dayjs("2024-09-12T17:10:00.000Z"), end: dayjs("2024-09-12T19:00:00.000Z") },
      ],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T11:00:00-07:00",
    ]);
  });

  it("shows 3 60minutes slots for availability like 08:00-12:00 with 10:00-10:10 busytime, when showOptimizedSlots set to false", async () => {
    const slots = getSlots({
      showOptimizedSlots: false,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:08:00, end:10:00
      // start:10:10, end:12:00
      // with 10:00 - 10:10 busy time
      dateRanges: [
        { start: dayjs("2024-09-12T15:00:00.000Z"), end: dayjs("2024-09-12T17:00:00.000Z") },
        { start: dayjs("2024-09-12T17:10:00.000Z"), end: dayjs("2024-09-12T19:00:00.000Z") },
      ],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T11:00:00-07:00",
    ]);
  });

  it("shows 9 30minutes slots for availability like 08:00-12:45 with 10:00-10:10 busytime, when showOptimizedSlots set to true", async () => {
    const slots = getSlots({
      showOptimizedSlots: true,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 30,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:08:00, end:10:00
      // start:10:10, end:12:45
      // with 10:00 - 10:10 busy time
      dateRanges: [
        { start: dayjs("2024-09-12T15:00:00.000Z"), end: dayjs("2024-09-12T17:00:00.000Z") },
        { start: dayjs("2024-09-12T17:10:00.000Z"), end: dayjs("2024-09-12T19:45:00.000Z") },
      ],
      minimumBookingNotice: 0,
      frequency: 30,
    });

    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T08:30:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T09:30:00-07:00",
      "2024-09-12T10:15:00-07:00",
      "2024-09-12T10:45:00-07:00",
      "2024-09-12T11:15:00-07:00",
      "2024-09-12T11:45:00-07:00",
      "2024-09-12T12:15:00-07:00",
    ]);
  });

  it("shows 8 30minutes slots for availability like 08:00-12:45 with 10:00-10:10 busytime, when showOptimizedSlots set to false", async () => {
    const slots = getSlots({
      showOptimizedSlots: false,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 30,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:08:00, end:10:00
      // start:10:10, end:12:45
      // with 10:00 - 10:10 busy time
      dateRanges: [
        { start: dayjs("2024-09-12T15:00:00.000Z"), end: dayjs("2024-09-12T17:00:00.000Z") },
        { start: dayjs("2024-09-12T17:10:00.000Z"), end: dayjs("2024-09-12T19:45:00.000Z") },
      ],
      minimumBookingNotice: 0,
      frequency: 30,
    });

    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T08:30:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T09:30:00-07:00",
      "2024-09-12T10:30:00-07:00",
      "2024-09-12T11:00:00-07:00",
      "2024-09-12T11:30:00-07:00",
      "2024-09-12T12:00:00-07:00",
    ]);
  });

  it("shows 13 20minutes slots for availability like 08:00-12:30 with 10:00-10:10 busytime, when showOptimizedSlots set to true", async () => {
    const slots = getSlots({
      showOptimizedSlots: true,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 20,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:08:00, end:10:00
      // start:10:10, end:12:30
      // with 10:00 - 10:10 busy time
      dateRanges: [
        { start: dayjs("2024-09-12T15:00:00.000Z"), end: dayjs("2024-09-12T17:00:00.000Z") },
        { start: dayjs("2024-09-12T17:10:00.000Z"), end: dayjs("2024-09-12T19:30:00.000Z") },
      ],
      minimumBookingNotice: 0,
      frequency: 20,
    });

    expect(slots.length).toStrictEqual(13);
    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T08:20:00-07:00",
      "2024-09-12T08:40:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T09:20:00-07:00",
      "2024-09-12T09:40:00-07:00",
      "2024-09-12T10:10:00-07:00",
      "2024-09-12T10:30:00-07:00",
      "2024-09-12T10:50:00-07:00",
      "2024-09-12T11:10:00-07:00",
      "2024-09-12T11:30:00-07:00",
      "2024-09-12T11:50:00-07:00",
      "2024-09-12T12:10:00-07:00",
    ]);
  });

  it("shows 12 20minutes slots for availability like 08:00-12:30 with 10:00-10:10 busytime, when showOptimizedSlots set to false", async () => {
    const slots = getSlots({
      showOptimizedSlots: false,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 20,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:08:00, end:10:00
      // start:10:10, end:12:30
      // with 10:00 - 10:10 busy time
      dateRanges: [
        { start: dayjs("2024-09-12T15:00:00.000Z"), end: dayjs("2024-09-12T17:00:00.000Z") },
        { start: dayjs("2024-09-12T17:10:00.000Z"), end: dayjs("2024-09-12T19:30:00.000Z") },
      ],
      minimumBookingNotice: 0,
      frequency: 20,
    });

    expect(slots.length).toStrictEqual(12);
    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T08:20:00-07:00",
      "2024-09-12T08:40:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T09:20:00-07:00",
      "2024-09-12T09:40:00-07:00",
      "2024-09-12T10:20:00-07:00",
      "2024-09-12T10:40:00-07:00",
      "2024-09-12T11:00:00-07:00",
      "2024-09-12T11:20:00-07:00",
      "2024-09-12T11:40:00-07:00",
      "2024-09-12T12:00:00-07:00",
    ]);
  });

  it("shows 8 60minutes slots for availability like 09:30-17:30, when showOptimizedSlots set to true", async () => {
    const slots = getSlots({
      showOptimizedSlots: true,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:09:30, end:17:30
      dateRanges: [{ start: dayjs("2024-09-12T16:30:00.000Z"), end: dayjs("2024-09-13T00:30:00.000Z") }],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.length).toStrictEqual(8);
    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T09:30:00-07:00",
      "2024-09-12T10:30:00-07:00",
      "2024-09-12T11:30:00-07:00",
      "2024-09-12T12:30:00-07:00",
      "2024-09-12T13:30:00-07:00",
      "2024-09-12T14:30:00-07:00",
      "2024-09-12T15:30:00-07:00",
      "2024-09-12T16:30:00-07:00",
    ]);
  });

  it("shows 7 60minutes slots for availability like 09:30-17:30, when showOptimizedSlots set to false", async () => {
    const slots = getSlots({
      showOptimizedSlots: false,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:09:30, end:17:30
      dateRanges: [{ start: dayjs("2024-09-12T16:30:00.000Z"), end: dayjs("2024-09-13T00:30:00.000Z") }],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.length).toStrictEqual(7);
    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T10:00:00-07:00",
      "2024-09-12T11:00:00-07:00",
      "2024-09-12T12:00:00-07:00",
      "2024-09-12T13:00:00-07:00",
      "2024-09-12T14:00:00-07:00",
      "2024-09-12T15:00:00-07:00",
      "2024-09-12T16:00:00-07:00",
    ]);
  });

  it("should respect start of the hour for 60minutes slots for availabilities like 07:45-15:30, even when showOptimizedSlots set to true", async () => {
    const slots = getSlots({
      showOptimizedSlots: true,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:07:45, end:15:30
      dateRanges: [{ start: dayjs("2024-09-12T14:45:00.000Z"), end: dayjs("2024-09-12T22:30:00.000Z") }],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.length).toStrictEqual(7);
    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T10:00:00-07:00",
      "2024-09-12T11:00:00-07:00",
      "2024-09-12T12:00:00-07:00",
      "2024-09-12T13:00:00-07:00",
      "2024-09-12T14:00:00-07:00",
    ]);
  });

  it("should respect start of the hour for 60minutes slots for availabilities like 07:45-15:30, when showOptimizedSlots set to false", async () => {
    const slots = getSlots({
      showOptimizedSlots: false,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:07:45, end:15:30
      dateRanges: [{ start: dayjs("2024-09-12T14:45:00.000Z"), end: dayjs("2024-09-12T22:30:00.000Z") }],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.length).toStrictEqual(7);
    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T08:00:00-07:00",
      "2024-09-12T09:00:00-07:00",
      "2024-09-12T10:00:00-07:00",
      "2024-09-12T11:00:00-07:00",
      "2024-09-12T12:00:00-07:00",
      "2024-09-12T13:00:00-07:00",
      "2024-09-12T14:00:00-07:00",
    ]);
  });

  it("should respect start of the hour for 60minutes slots for availabilities like 09:05-12:55, even when showOptimizedSlots set to true", async () => {
    const slots = getSlots({
      showOptimizedSlots: true,
      inviteeDate: dayjs.tz("2024-09-12T00:00:00.000-07:00", "America/Los_Angeles"),
      eventLength: 60,
      offsetStart: 0,
      // equivalent dateRanges in UTC-7
      // start:09:05, end:12:55
      dateRanges: [{ start: dayjs("2024-09-12T16:05:00.000Z"), end: dayjs("2024-09-12T19:55:00.000Z") }],
      minimumBookingNotice: 0,
      frequency: 60,
    });

    expect(slots.length).toStrictEqual(3);
    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2024-09-12T09:15:00-07:00",
      "2024-09-12T10:15:00-07:00",
      "2024-09-12T11:15:00-07:00",
    ]);
  });

  it("adjusts slot start time to next 5-minute boundary for current day bookings with non-aligned start time", async () => {
    // Set system time to 2021-06-20 11:20:00 UTC
    vi.setSystemTime(dayjs.utc("2021-06-20T11:20:00.000Z").toDate());

    const slots = getSlots({
      inviteeDate: dayjs.tz("2021-06-20T00:00:00.000Z", "America/Los_Angeles"),
      frequency: 15,
      minimumBookingNotice: 0,
      eventLength: 15,
      dateRanges: [
        {
          start: dayjs.tz("2021-06-20T11:22:00.000", "America/Los_Angeles"),
          end: dayjs.tz("2021-06-20T12:55:00.000", "America/Los_Angeles"),
        },
      ],
      offsetStart: 0,
      showOptimizedSlots: true,
    });

    expect(slots.length).toStrictEqual(6);
    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2021-06-20T11:25:00-07:00",
      "2021-06-20T11:40:00-07:00",
      "2021-06-20T11:55:00-07:00",
      "2021-06-20T12:10:00-07:00",
      "2021-06-20T12:25:00-07:00",
      "2021-06-20T12:40:00-07:00",
    ]);

    vi.useRealTimers();
  });

  it("should respect start of the hour for current day bookings with non-aligned start time", async () => {
    // Set system time to 2021-06-20 11:20:00 UTC
    vi.setSystemTime(dayjs.utc("2021-06-20T11:20:00.000Z").toDate());

    const slots = getSlots({
      inviteeDate: dayjs.tz("2021-06-20T00:00:00.000Z", "America/Los_Angeles"),
      frequency: 60,
      minimumBookingNotice: 0,
      eventLength: 60,
      dateRanges: [
        {
          start: dayjs.tz("2021-06-20T11:22:36.234", "America/Los_Angeles"), //with seconds
          end: dayjs.tz("2021-06-20T14:00:00.000", "America/Los_Angeles"),
        },
      ],
      offsetStart: 0,
      showOptimizedSlots: true,
    });

    expect(slots.length).toStrictEqual(2);
    expect(slots.map((slot) => slot.time.format())).toStrictEqual([
      "2021-06-20T12:00:00-07:00",
      "2021-06-20T13:00:00-07:00",
    ]);

    vi.useRealTimers();
  });

  it("should mark slots as away when OOO is on next day and availability extends past midnight", async () => {
    // This test reproduces the bug where:
    // - Day 1 has availability from 00:00 to 23:59
    // - Day 2 is marked as OOO
    // - Slots generated after midnight are not marked as away

    vi.setSystemTime(dayjs.utc("2025-11-17T00:00:00Z").toDate());

    const day1Start = dayjs.utc("2025-11-17T00:00:00Z");
    const day2End = dayjs.utc("2025-11-18T23:59:59Z");

    // OOO data for Day 2 (2025-11-18)
    const datesOutOfOffice = {
      "2025-11-18": {
        fromUser: { id: 1, displayName: "Test User" },
        toUser: null,
        reason: "Out of office",
        emoji: "🏖️",
      },
    };

    const slots = getSlots({
      inviteeDate: day1Start,
      frequency: 15,
      minimumBookingNotice: 0,
      eventLength: 15,
      dateRanges: [
        {
          start: day1Start,
          end: day2End,
        },
      ],
      datesOutOfOffice,
      datesOutOfOfficeTimeZone: "UTC",
    });

    const day1Slots = slots.filter((slot) => slot.time.format("YYYY-MM-DD") === "2025-11-17");
    const day2Slots = slots.filter((slot) => slot.time.format("YYYY-MM-DD") === "2025-11-18");

    // Day 1 slots should NOT be marked as away
    day1Slots.forEach((slot) => {
      expect(slot.away).toBeUndefined();
    });

    expect(day2Slots.length).toBeGreaterThan(0);

    // Day 2 slots should be marked as away
    day2Slots.forEach((slot) => {
      expect(slot.away).toBe(true);
      expect(slot.reason).toBe("Out of office");
      expect(slot.emoji).toBe("🏖️");
    });

    vi.useRealTimers();
  });

  it("should mark slots as away for cross-timezone OOO (Berlin OOO viewed from Kolkata)", async () => {
    vi.setSystemTime(dayjs.utc("2024-12-20T00:00:00Z").toDate());

    const datesOutOfOffice = {
      "2024-12-22": {
        fromUser: { id: 1, displayName: "Test User" },
        toUser: null,
        reason: "Holiday",
        emoji: "🎄",
      },
    };

    const dateRanges = [
      {
        start: dayjs.tz("2024-12-22T09:00:00", "Europe/Berlin"),
        end: dayjs.tz("2024-12-22T18:00:00", "Europe/Berlin"),
      },
    ];

    const inviteeDate = dayjs.tz("2024-12-22T13:30:00", "Asia/Kolkata");

    const slots = getSlots({
      inviteeDate,
      frequency: 30,
      minimumBookingNotice: 0,
      eventLength: 30,
      dateRanges,
      datesOutOfOffice,
      datesOutOfOfficeTimeZone: "Europe/Berlin",
    });

    expect(slots.length).toBeGreaterThan(0);
    slots.forEach((slot) => {
      expect(slot.away).toBe(true);
      expect(slot.reason).toBe("Holiday");
    });

    vi.useRealTimers();
  });

  it("should correctly handle OOO when slot time crosses UTC date boundary", async () => {
    vi.setSystemTime(dayjs.utc("2024-12-20T00:00:00Z").toDate());

    const datesOutOfOffice = {
      "2024-12-22": {
        fromUser: { id: 1, displayName: "Test User" },
        toUser: null,
        reason: "OOO",
        emoji: "🏖️",
      },
    };

    const dateRanges = [
      {
        start: dayjs.utc("2024-12-22T22:00:00Z"),
        end: dayjs.utc("2024-12-22T23:59:59Z"),
      },
    ];

    const inviteeDate = dayjs.tz("2024-12-23T03:30:00", "Asia/Kolkata");

    const slots = getSlots({
      inviteeDate,
      frequency: 30,
      minimumBookingNotice: 0,
      eventLength: 30,
      dateRanges,
      datesOutOfOffice,
    });

    expect(slots.length).toBeGreaterThan(0);
    slots.forEach((slot) => {
      expect(slot.away).toBe(true);
    });

    vi.useRealTimers();
  });

  it("should NOT mark slots as away when they fall outside OOO UTC date", async () => {
    vi.setSystemTime(dayjs.utc("2024-12-20T00:00:00Z").toDate());

    const datesOutOfOffice = {
      "2024-12-22": {
        fromUser: { id: 1, displayName: "Test User" },
        toUser: null,
        reason: "OOO",
        emoji: "🏖️",
      },
    };

    const dateRanges = [
      {
        start: dayjs.utc("2024-12-21T17:00:00Z"),
        end: dayjs.utc("2024-12-21T20:00:00Z"),
      },
    ];

    const inviteeDate = dayjs.tz("2024-12-21T22:30:00", "Asia/Kolkata");

    const slots = getSlots({
      inviteeDate,
      frequency: 30,
      minimumBookingNotice: 0,
      eventLength: 30,
      dateRanges,
      datesOutOfOffice,
    });

    expect(slots.length).toBeGreaterThan(0);
    slots.forEach((slot) => {
      expect(slot.away).toBeUndefined();
    });

    vi.useRealTimers();
  });

  it("should mark slots as away when host OOO day maps to next UTC day (LA host, Kolkata booker)", async () => {
    vi.setSystemTime(dayjs.utc("2026-01-10T00:00:00Z").toDate());

    const datesOutOfOffice = {
      "2026-01-16": {
        fromUser: { id: 1, displayName: "Host User" },
        toUser: null,
        reason: "OOO",
        emoji: "🏖️",
      },
    };

    const dateRanges = [
      {
        start: dayjs.tz("2026-01-16T16:00:00", "America/Los_Angeles"),
        end: dayjs.tz("2026-01-16T17:00:00", "America/Los_Angeles"),
      },
    ];

    const inviteeDate = dayjs.tz("2026-01-17T00:00:00", "Asia/Kolkata");

    const slots = getSlots({
      inviteeDate,
      frequency: 30,
      minimumBookingNotice: 0,
      eventLength: 30,
      dateRanges,
      datesOutOfOffice,
      datesOutOfOfficeTimeZone: "America/Los_Angeles",
    });

    const targetSlot = slots.find(
      (slot) => slot.time.tz("Asia/Kolkata").format("YYYY-MM-DD HH:mm") === "2026-01-17 05:30"
    );

    expect(targetSlot).toBeDefined();
    expect(targetSlot?.away).toBe(true);
    expect(targetSlot?.reason).toBe("OOO");

    vi.useRealTimers();
  });
});

describe("Tests 40-minute duration slot generation", () => {
  beforeAll(() => {
    vi.setSystemTime(dayjs.utc("2021-06-20T11:59:59Z").toDate());
  });

  it("generates correct number of 40-minute slots for a full day", async () => {
    const nextDay = dayjs.utc().add(1, "day").startOf("day");
    const dateRanges = [
      {
        start: nextDay,
        end: nextDay.endOf("day"),
      },
    ];

    const slots = getSlots({
      inviteeDate: nextDay,
      frequency: 40,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 40,
      offsetStart: 0,
    });

    // 24 hours = 1440 minutes, 1440 / 40 = 36 slots
    expect(slots).toHaveLength(36);
  });

  it("generates 40-minute slots with correct time intervals", async () => {
    const nextDay = dayjs.utc().add(1, "day").startOf("day");
    const dateRanges = [
      {
        start: nextDay.hour(9),
        end: nextDay.hour(11),
      },
    ];

    const slots = getSlots({
      inviteeDate: nextDay,
      frequency: 40,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 40,
      offsetStart: 0,
    });

    // 2 hours = 120 minutes, 120 / 40 = 3 slots (9:00, 9:40, 10:20)
    expect(slots).toHaveLength(3);
    expect(slots[0].time.format("HH:mm")).toBe("09:00");
    expect(slots[1].time.format("HH:mm")).toBe("09:40");
    expect(slots[2].time.format("HH:mm")).toBe("10:20");
  });

  it("handles 40-minute slots as default duration in variable length event", async () => {
    const nextDay = dayjs.utc().add(1, "day").startOf("day");
    const dateRanges = [
      {
        start: nextDay.hour(10),
        end: nextDay.hour(12),
      },
    ];

    const slots = getSlots({
      inviteeDate: nextDay,
      frequency: 40,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 40,
      offsetStart: 0,
    });

    // 2 hours = 120 minutes, 120 / 40 = 3 slots
    expect(slots).toHaveLength(3);
    // Verify each slot has correct 40-minute spacing
    for (let i = 1; i < slots.length; i++) {
      const diff = slots[i].time.diff(slots[i - 1].time, "minute");
      expect(diff).toBe(40);
    }
  });

  it("generates 40-minute slots with minimum booking notice on same day", async () => {
    // System time is set to 2021-06-20T11:59:59Z (almost noon)
    const today = dayjs.utc().startOf("day");
    const dateRanges = [
      {
        start: today,
        end: today.endOf("day"),
      },
    ];

    const slots = getSlots({
      inviteeDate: today,
      frequency: 40,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 40,
      offsetStart: 0,
    });

    // System time is ~12:00, so only slots from 12:00 onwards should be available
    // From 12:00 to 24:00 = 12 hours = 720 minutes, 720 / 40 = 18 slots
    expect(slots).toHaveLength(18);
  });

  it("handles 40-minute slots across multiple date ranges", async () => {
    const nextDay = dayjs.utc().add(1, "day").startOf("day");
    const dateRanges = [
      {
        start: nextDay.hour(9),
        end: nextDay.hour(10).minute(20),
      },
      {
        start: nextDay.hour(14),
        end: nextDay.hour(15).minute(20),
      },
    ];

    const slots = getSlots({
      inviteeDate: nextDay,
      frequency: 40,
      minimumBookingNotice: 0,
      dateRanges: dateRanges,
      eventLength: 40,
      offsetStart: 0,
    });

    // First range: 9:00-10:20 = 80 minutes = 2 slots (9:00, 9:40)
    // Second range: 14:00-15:20 = 80 minutes = 2 slots (14:00, 14:40)
    expect(slots).toHaveLength(4);
  });
});