// ABOUTME: Unit tests for ICS calendar feed API route.
// ABOUTME: Tests GET /api/calendar/[userId]/[token].ics for token validation and ICS generation.

import type { NextRequest } from "next/server";
import { beforeEach, describe, expect, it, vi } from "vitest";

import type { PeriodLog, User } from "@/types";

// Module-level variable to control mock user lookup
let mockUsers: Map<string, User> = new Map();
let mockPeriodLogs: PeriodLog[] = [];

// Mock PocketBase
vi.mock("@/lib/pocketbase", () => ({
  createPocketBaseClient: vi.fn(() => ({
    collection: vi.fn((name: string) => {
      if (name === "users") {
        return {
          getOne: vi.fn((userId: string) => {
            const user = mockUsers.get(userId);
            if (!user) {
              const error = new Error("Not found");
              (error as unknown as { status: number }).status = 404;
              throw error;
            }
            return {
              id: user.id,
              email: user.email,
              calendarToken: user.calendarToken,
              // biome-ignore lint/style/noNonNullAssertion: mock user has valid date
              lastPeriodDate: user.lastPeriodDate!.toISOString(),
              cycleLength: user.cycleLength,
              garminConnected: user.garminConnected,
            };
          }),
        };
      }
      if (name === "period_logs") {
        return {
          getFullList: vi.fn(() =>
            mockPeriodLogs.map((log) => ({
              id: log.id,
              user: log.user,
              startDate: log.startDate.toISOString(),
              predictedDate: log.predictedDate?.toISOString() ?? null,
              created: log.created.toISOString(),
            })),
          ),
        };
      }
      return {};
    }),
  })),
}));

// Mock ICS generation
const mockGenerateIcsFeed = vi.fn().mockReturnValue(`BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//PhaseFlow//EN
BEGIN:VEVENT
SUMMARY:🔵 MENSTRUAL
DTSTART:20250101
DTEND:20250105
END:VEVENT
END:VCALENDAR`);

vi.mock("@/lib/ics", () => ({
  generateIcsFeed: (options: { lastPeriodDate: Date; cycleLength: number }) =>
    mockGenerateIcsFeed(options),
}));

import { GET } from "./route";

describe("GET /api/calendar/[userId]/[token].ics", () => {
  const mockUser: User = {
    id: "user123",
    email: "test@example.com",
    garminConnected: true,
    garminOauth1Token: "encrypted-token-1",
    garminOauth2Token: "encrypted-token-2",
    garminTokenExpiresAt: new Date("2025-06-01"),
    garminRefreshTokenExpiresAt: null,
    calendarToken: "valid-calendar-token-abc123def",
    lastPeriodDate: new Date("2025-01-15"),
    cycleLength: 28,
    notificationTime: "07:30",
    timezone: "America/New_York",
    activeOverrides: [],
    intensityGoalMenstrual: 75,
    intensityGoalFollicular: 150,
    intensityGoalOvulation: 100,
    intensityGoalEarlyLuteal: 120,
    intensityGoalLateLuteal: 50,
    created: new Date("2024-01-01"),
    updated: new Date("2025-01-10"),
  };

  beforeEach(() => {
    vi.clearAllMocks();
    mockUsers = new Map();
    mockUsers.set("user123", mockUser);
    mockPeriodLogs = [];
  });

  // Helper to create route context with params
  function createRouteContext(userId: string, token: string) {
    return {
      params: Promise.resolve({ userId, token }),
    };
  }

  it("returns 401 for invalid token", async () => {
    const mockRequest = {} as NextRequest;
    const context = createRouteContext("user123", "wrong-token");

    const response = await GET(mockRequest, context);

    expect(response.status).toBe(401);
    const body = await response.json();
    expect(body.error).toContain("Unauthorized");
  });

  it("returns 404 for non-existent user", async () => {
    const mockRequest = {} as NextRequest;
    const context = createRouteContext("nonexistent", "some-token");

    const response = await GET(mockRequest, context);

    expect(response.status).toBe(404);
    const body = await response.json();
    expect(body.error).toContain("not found");
  });

  it("returns 401 when user has no calendar token set", async () => {
    mockUsers.set("user456", {
      ...mockUser,
      id: "user456",
      calendarToken: "",
    });

    const mockRequest = {} as NextRequest;
    const context = createRouteContext("user456", "any-token");

    const response = await GET(mockRequest, context);

    expect(response.status).toBe(401);
  });

  it("returns ICS content for valid token", async () => {
    const mockRequest = {} as NextRequest;
    const context = createRouteContext(
      "user123",
      "valid-calendar-token-abc123def",
    );

    const response = await GET(mockRequest, context);

    expect(response.status).toBe(200);
    const text = await response.text();
    expect(text).toContain("BEGIN:VCALENDAR");
    expect(text).toContain("END:VCALENDAR");
  });

  it("returns correct Content-Type header", async () => {
    const mockRequest = {} as NextRequest;
    const context = createRouteContext(
      "user123",
      "valid-calendar-token-abc123def",
    );

    const response = await GET(mockRequest, context);

    expect(response.headers.get("Content-Type")).toBe(
      "text/calendar; charset=utf-8",
    );
  });

  it("calls generateIcsFeed with correct parameters", async () => {
    const mockRequest = {} as NextRequest;
    const context = createRouteContext(
      "user123",
      "valid-calendar-token-abc123def",
    );

    await GET(mockRequest, context);

    expect(mockGenerateIcsFeed).toHaveBeenCalledWith(
      expect.objectContaining({
        lastPeriodDate: expect.any(Date),
        cycleLength: 28,
      }),
    );
  });

  it("generates 90 days of events (monthsAhead = 3)", async () => {
    const mockRequest = {} as NextRequest;
    const context = createRouteContext(
      "user123",
      "valid-calendar-token-abc123def",
    );

    await GET(mockRequest, context);

    expect(mockGenerateIcsFeed).toHaveBeenCalledWith(
      expect.objectContaining({
        monthsAhead: 3,
      }),
    );
  });

  it("handles different cycle lengths", async () => {
    mockUsers.set("user789", {
      ...mockUser,
      id: "user789",
      calendarToken: "token789",
      cycleLength: 35,
    });

    const mockRequest = {} as NextRequest;
    const context = createRouteContext("user789", "token789");

    await GET(mockRequest, context);

    expect(mockGenerateIcsFeed).toHaveBeenCalledWith(
      expect.objectContaining({
        cycleLength: 35,
      }),
    );
  });

  it("includes Cache-Control header for caching", async () => {
    const mockRequest = {} as NextRequest;
    const context = createRouteContext(
      "user123",
      "valid-calendar-token-abc123def",
    );

    const response = await GET(mockRequest, context);

    // Calendar feeds should be cacheable but refresh periodically
    const cacheControl = response.headers.get("Cache-Control");
    expect(cacheControl).toBeDefined();
    expect(cacheControl).toContain("max-age");
  });

  it("is case-sensitive for token matching", async () => {
    const mockRequest = {} as NextRequest;
    // Token with different case should fail
    const context = createRouteContext(
      "user123",
      "VALID-CALENDAR-TOKEN-ABC123DEF",
    );

    const response = await GET(mockRequest, context);

    expect(response.status).toBe(401);
  });

  it("passes period logs to ICS generator for prediction accuracy", async () => {
    mockPeriodLogs = [
      {
        id: "log1",
        user: "user123",
        startDate: new Date("2025-01-10"),
        predictedDate: new Date("2025-01-12"), // 2 days early
        created: new Date("2025-01-10"),
      },
      {
        id: "log2",
        user: "user123",
        startDate: new Date("2024-12-15"),
        predictedDate: null, // First log, no prediction
        created: new Date("2024-12-15"),
      },
    ];

    const mockRequest = {} as NextRequest;
    const context = createRouteContext(
      "user123",
      "valid-calendar-token-abc123def",
    );

    await GET(mockRequest, context);

    expect(mockGenerateIcsFeed).toHaveBeenCalledWith(
      expect.objectContaining({
        periodLogs: expect.arrayContaining([
          expect.objectContaining({
            id: "log1",
            startDate: expect.any(Date),
            predictedDate: expect.any(Date),
          }),
          expect.objectContaining({
            id: "log2",
            predictedDate: null,
          }),
        ]),
      }),
    );
  });
});