import { describe, expect, it } from "vitest";

import { parseICalendarBytes } from "@/worker/caldav/ical/parse";
import { expandCalendarData } from "@/worker/caldav/ical/render";
import { calendarObjectMatchesFilters } from "@/worker/caldav/ical/search";
import { utf8ArrayBuffer } from "@tests/worker/helpers/bytes";

const bounds = { maxYears: 5, maxInstances: 10_000 };

function ms(value: string): number {
  const match = /^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})Z$/.exec(value);
  if (!match) throw new Error(`Invalid test timestamp ${value}`);
  return Date.UTC(
    Number(match[1]),
    Number(match[2]) - 1,
    Number(match[3]),
    Number(match[4]),
    Number(match[5]),
    Number(match[6]),
  );
}

function ical(lines: string[]): string {
  return [...lines, ""].join("\r\n");
}

describe("CalDAV iCalendar helpers", () => {
  it("indexes recurrence sets with RDATE and EXDATE", () => {
    const body = ical([
      "BEGIN:VCALENDAR",
      "VERSION:2.0",
      "PRODID:-//dab//tests//EN",
      "BEGIN:VEVENT",
      "DTSTAMP:20260101T000000Z",
      "UID:recurrence-set@example.test",
      "SUMMARY:Recurrence Set",
      "DTSTART:20260521T120000Z",
      "DTEND:20260521T130000Z",
      "RRULE:FREQ=DAILY;COUNT=2",
      "RDATE:20260524T120000Z",
      "EXDATE:20260522T120000Z",
      "END:VEVENT",
      "END:VCALENDAR",
    ]);

    const parsed = parseICalendarBytes(utf8ArrayBuffer(body), 1_048_576, bounds);

    expect(parsed.hasRecurrence).toBe(true);
    expect(parsed.recurrenceMinMs).toBe(ms("20260521T120000Z"));
    expect(parsed.recurrenceMaxMs).toBe(ms("20260524T130000Z"));
    expect(
      calendarObjectMatchesFilters(
        body,
        [{ kind: "time-range", range: { startMs: ms("20260522T000000Z"), endMs: ms("20260523T000000Z") } }],
        bounds,
      ),
    ).toBe(false);
    expect(
      calendarObjectMatchesFilters(
        body,
        [{ kind: "time-range", range: { startMs: ms("20260524T000000Z"), endMs: ms("20260525T000000Z") } }],
        bounds,
      ),
    ).toBe(true);
  });

  it("matches generic property filters and VTODO time ranges", () => {
    const body = ical([
      "BEGIN:VCALENDAR",
      "VERSION:2.0",
      "PRODID:-//dab//tests//EN",
      "BEGIN:VTODO",
      "DTSTAMP:20260101T000000Z",
      "UID:todo@example.test",
      "SUMMARY:Todo",
      "DTSTART:20260521T120000Z",
      "DUE:20260523T120000Z",
      "CATEGORIES:Focus,Team",
      "END:VTODO",
      "END:VCALENDAR",
    ]);

    expect(
      calendarObjectMatchesFilters(
        body,
        [
          { kind: "component", component: "VTODO" },
          { kind: "property-text", name: "CATEGORIES", text: "focus" },
          { kind: "property-defined", name: "LOCATION", defined: false },
          { kind: "time-range", range: { startMs: ms("20260522T000000Z"), endMs: ms("20260522T010000Z") } },
        ],
        bounds,
      ),
    ).toBe(true);
    expect(
      calendarObjectMatchesFilters(
        body,
        [{ kind: "time-range", range: { startMs: ms("20260524T000000Z"), endMs: ms("20260525T000000Z") } }],
        bounds,
      ),
    ).toBe(false);
  });

  it("indexes IANA TZID date-times for time-range matching", () => {
    const body = ical([
      "BEGIN:VCALENDAR",
      "VERSION:2.0",
      "PRODID:-//dab//tests//EN",
      "BEGIN:VEVENT",
      "DTSTAMP:20260101T000000Z",
      "UID:tzid@example.test",
      "SUMMARY:TZID",
      "DTSTART;TZID=America/Los_Angeles:20260521T090000",
      "DTEND;TZID=America/Los_Angeles:20260521T100000",
      "END:VEVENT",
      "END:VCALENDAR",
    ]);

    const parsed = parseICalendarBytes(utf8ArrayBuffer(body), 1_048_576, bounds);
    expect(parsed.dtstartMs).toBe(ms("20260521T160000Z"));
    expect(
      calendarObjectMatchesFilters(
        body,
        [{ kind: "time-range", range: { startMs: ms("20260521T153000Z"), endMs: ms("20260521T163000Z") } }],
        bounds,
      ),
    ).toBe(true);
  });

  it("treats floating date-times as UTC for indexed time-range matching", () => {
    const body = ical([
      "BEGIN:VCALENDAR",
      "VERSION:2.0",
      "PRODID:-//dab//tests//EN",
      "BEGIN:VEVENT",
      "DTSTAMP:20260101T000000Z",
      "UID:floating@example.test",
      "SUMMARY:Floating",
      "DTSTART:20260521T090000",
      "DTEND:20260521T100000",
      "END:VEVENT",
      "END:VCALENDAR",
    ]);

    const parsed = parseICalendarBytes(utf8ArrayBuffer(body), 1_048_576, bounds);
    expect(parsed.dtstartMs).toBe(ms("20260521T090000Z"));
    expect(
      calendarObjectMatchesFilters(
        body,
        [{ kind: "time-range", range: { startMs: ms("20260521T083000Z"), endMs: ms("20260521T093000Z") } }],
        bounds,
      ),
    ).toBe(true);
  });

  it("rejects unsupported RRULE parts instead of silently broadening results", () => {
    const body = ical([
      "BEGIN:VCALENDAR",
      "VERSION:2.0",
      "PRODID:-//dab//tests//EN",
      "BEGIN:VEVENT",
      "DTSTAMP:20260101T000000Z",
      "UID:unsupported-rrule@example.test",
      "SUMMARY:Unsupported",
      "DTSTART:20260521T120000Z",
      "DTEND:20260521T130000Z",
      "RRULE:FREQ=MONTHLY;BYSETPOS=1;BYDAY=MO",
      "END:VEVENT",
      "END:VCALENDAR",
    ]);

    expect(() => parseICalendarBytes(utf8ArrayBuffer(body), 1_048_576, bounds)).toThrow(
      "Unsupported RRULE part BYSETPOS",
    );
  });

  it("expands recurrence overrides and omits cancelled instances", () => {
    const body = ical([
      "BEGIN:VCALENDAR",
      "VERSION:2.0",
      "PRODID:-//dab//tests//EN",
      "BEGIN:VEVENT",
      "DTSTAMP:20260101T000000Z",
      "UID:expanded@example.test",
      "SUMMARY:Daily",
      "DTSTART:20260521T120000Z",
      "DTEND:20260521T130000Z",
      "RRULE:FREQ=DAILY;COUNT=3",
      "END:VEVENT",
      "BEGIN:VEVENT",
      "DTSTAMP:20260101T000000Z",
      "UID:expanded@example.test",
      "RECURRENCE-ID:20260522T120000Z",
      "SUMMARY:Moved Daily",
      "DTSTART:20260522T150000Z",
      "DTEND:20260522T160000Z",
      "END:VEVENT",
      "BEGIN:VEVENT",
      "DTSTAMP:20260101T000000Z",
      "UID:expanded@example.test",
      "RECURRENCE-ID:20260523T120000Z",
      "STATUS:CANCELLED",
      "SUMMARY:Cancelled Daily",
      "DTSTART:20260523T120000Z",
      "DTEND:20260523T130000Z",
      "END:VEVENT",
      "END:VCALENDAR",
    ]);

    const expanded = expandCalendarData(
      body,
      { startMs: ms("20260521T000000Z"), endMs: ms("20260524T000000Z") },
      bounds,
    );

    expect(expanded).toContain("RECURRENCE-ID:20260522T120000Z");
    expect(expanded).toContain("SUMMARY:Moved Daily");
    expect(expanded).toContain("DTSTART:20260522T150000Z");
    expect(expanded).not.toContain("RRULE:FREQ=DAILY");
    expect(expanded).not.toContain("SUMMARY:Cancelled Daily");
  });

  it("keeps THISANDFUTURE range overrides in expanded output", () => {
    const body = ical([
      "BEGIN:VCALENDAR",
      "VERSION:2.0",
      "PRODID:-//dab//tests//EN",
      "BEGIN:VEVENT",
      "DTSTAMP:20260101T000000Z",
      "UID:this-and-future@example.test",
      "SUMMARY:Daily",
      "DTSTART:20260521T120000Z",
      "DTEND:20260521T130000Z",
      "RRULE:FREQ=DAILY;COUNT=4",
      "END:VEVENT",
      "BEGIN:VEVENT",
      "DTSTAMP:20260101T000000Z",
      "UID:this-and-future@example.test",
      "RECURRENCE-ID;RANGE=THISANDFUTURE:20260522T120000Z",
      "SUMMARY:Shift Future",
      "DTSTART:20260522T150000Z",
      "DTEND:20260522T160000Z",
      "END:VEVENT",
      "END:VCALENDAR",
    ]);

    const expanded = expandCalendarData(
      body,
      { startMs: ms("20260522T000000Z"), endMs: ms("20260524T000000Z") },
      bounds,
    );

    expect(expanded).toContain("RECURRENCE-ID:20260522T120000Z");
    expect(expanded).toContain("RECURRENCE-ID:20260523T120000Z");
    expect(expanded.match(/SUMMARY:Shift Future/g)?.length).toBeGreaterThanOrEqual(2);
  });
});