const {
  calculateRequestedDays,
  calculateRequestedDaysByWorkingCalendar,
  calculateRequestedDaysPreviewByWorkingCalendar,
  leaveRangesOverlap,
  summarizeLeaveLedgerEntries,
} = require("../../../src/services/leave");

describe("Leave Service", () => {
  describe("calculateRequestedDays", () => {
    it("supports same-day half-day requests", () => {
      expect(
        calculateRequestedDays({
          startDate: "2026-03-10",
          endDate: "2026-03-10",
          startSession: "am",
          endSession: "am",
        }),
      ).toBe(0.5);

      expect(
        calculateRequestedDays({
          startDate: "2026-03-10",
          endDate: "2026-03-10",
          startSession: "pm",
          endSession: "pm",
        }),
      ).toBe(0.5);
    });

    it("supports cross-day half-day boundaries", () => {
      expect(
        calculateRequestedDays({
          startDate: "2026-03-10",
          endDate: "2026-03-12",
          startSession: "pm",
          endSession: "am",
        }),
      ).toBe(2);
    });

    it("rejects invalid session ranges", () => {
      expect(() =>
        calculateRequestedDays({
          startDate: "2026-03-10",
          endDate: "2026-03-10",
          startSession: "pm",
          endSession: "am",
        }),
      ).toThrow(expect.objectContaining({ code: "VALID_001", statusCode: 422, details: { leave: "invalid_range", reasonCode: "leave.leave_invalid_range" } }));
    });
  });

  describe("calculateRequestedDaysByWorkingCalendar", () => {
    it("skips weekend days by default and respects adjusted workdays", () => {
      expect(
        calculateRequestedDaysByWorkingCalendar({
          startDate: "2026-03-20",
          endDate: "2026-03-22",
          startSession: "am",
          endSession: "pm",
          calendarDays: [],
        }),
      ).toBe(1);

      expect(
        calculateRequestedDaysByWorkingCalendar({
          startDate: "2026-03-20",
          endDate: "2026-03-22",
          startSession: "am",
          endSession: "pm",
          calendarDays: [{ date: "2026-03-21", day_type: "adjusted_workday" }],
        }),
      ).toBe(2);
    });

    it("skips configured holidays inside a weekday span", () => {
      expect(
        calculateRequestedDaysByWorkingCalendar({
          startDate: "2026-03-16",
          endDate: "2026-03-17",
          startSession: "am",
          endSession: "pm",
          calendarDays: [{ date: "2026-03-17", day_type: "holiday" }],
        }),
      ).toBe(1);
    });

    it("rejects ranges that become fully non-working after calendar adjustment", () => {
      expect(() =>
        calculateRequestedDaysByWorkingCalendar({
          startDate: "2026-03-21",
          endDate: "2026-03-22",
          startSession: "am",
          endSession: "pm",
          calendarDays: [],
        }),
      ).toThrow(expect.objectContaining({ code: "VALID_001", statusCode: 422, details: { leave: "non_working_range", reasonCode: "leave.leave_non_working_range" } }));
    });
  });

  describe("calculateRequestedDaysPreviewByWorkingCalendar", () => {
    it("returns official holiday counts while excluding holidays from requested days", () => {
      expect(
        calculateRequestedDaysPreviewByWorkingCalendar({
          startDate: "2026-01-01",
          endDate: "2026-01-04",
          startSession: "am",
          endSession: "pm",
          calendarDays: [
            { date: "2026-01-01", day_type: "holiday" },
            { date: "2026-01-02", day_type: "holiday" },
            { date: "2026-01-03", day_type: "holiday" },
            { date: "2026-01-04", day_type: "adjusted_workday" },
          ],
        }),
      ).toEqual({
        requestedDays: 1,
        naturalRequestedDays: 4,
        holidayDayCount: 3,
        weekendDayCount: 0,
        adjustedWorkdayCount: 1,
        calendarApplied: true,
        isNonWorkingRange: false,
      });
    });

    it("keeps half-day precision for adjusted workdays in preview payload", () => {
      expect(
        calculateRequestedDaysPreviewByWorkingCalendar({
          startDate: "2026-01-03",
          endDate: "2026-01-04",
          startSession: "pm",
          endSession: "am",
          calendarDays: [
            { date: "2026-01-03", day_type: "holiday" },
            { date: "2026-01-04", day_type: "adjusted_workday" },
          ],
        }),
      ).toEqual({
        requestedDays: 0.5,
        naturalRequestedDays: 1,
        holidayDayCount: 0.5,
        weekendDayCount: 0,
        adjustedWorkdayCount: 0.5,
        calendarApplied: true,
        isNonWorkingRange: false,
      });
    });

    it("returns zero-day preview for fully non-working ranges when explicitly allowed", () => {
      expect(
        calculateRequestedDaysPreviewByWorkingCalendar({
          startDate: "2026-05-01",
          endDate: "2026-05-05",
          startSession: "am",
          endSession: "pm",
          allowNonWorkingRange: true,
          calendarDays: [
            { date: "2026-05-01", day_type: "holiday" },
            { date: "2026-05-02", day_type: "holiday" },
            { date: "2026-05-03", day_type: "holiday" },
            { date: "2026-05-04", day_type: "holiday" },
            { date: "2026-05-05", day_type: "holiday" },
          ],
        }),
      ).toEqual({
        requestedDays: 0,
        naturalRequestedDays: 5,
        holidayDayCount: 5,
        weekendDayCount: 0,
        adjustedWorkdayCount: 0,
        calendarApplied: true,
        isNonWorkingRange: true,
      });
    });
  });

  describe("leaveRangesOverlap", () => {
    it("detects overlapping half-day ranges", () => {
      expect(
        leaveRangesOverlap(
          {
            startDate: "2026-03-10",
            endDate: "2026-03-11",
            startSession: "pm",
            endSession: "pm",
          },
          {
            startDate: "2026-03-11",
            endDate: "2026-03-12",
            startSession: "am",
            endSession: "am",
          },
        ),
      ).toBe(true);
    });

    it("does not flag non-overlapping adjacent ranges", () => {
      expect(
        leaveRangesOverlap(
          {
            startDate: "2026-03-10",
            endDate: "2026-03-10",
            startSession: "am",
            endSession: "am",
          },
          {
            startDate: "2026-03-10",
            endDate: "2026-03-10",
            startSession: "pm",
            endSession: "pm",
          },
        ),
      ).toBe(false);
    });
  });

  describe("summarizeLeaveLedgerEntries", () => {
    it("calculates reserve / consume / release balances correctly", () => {
      const summary = summarizeLeaveLedgerEntries([
        { entry_type: "grant", days: 10 },
        { entry_type: "reserve", days: 2.5 },
        { entry_type: "release", days: 1 },
        { entry_type: "consume", days: 1.5 },
      ]);

      expect(summary.granted).toBe(10);
      expect(summary.reserved).toBe(1.5);
      expect(summary.used).toBe(1.5);
      expect(summary.available).toBe(7);
    });
  });
});