// ABOUTME: Unit tests for email sending utilities.
// ABOUTME: Tests email composition, subject lines, and Resend integration.
import { afterEach, describe, expect, it, vi } from "vitest";

const { mockSend } = vi.hoisted(() => ({
  mockSend: vi.fn().mockResolvedValue({ id: "mock-email-id" }),
}));

// Mock the resend module before importing email utilities
vi.mock("resend", () => ({
  Resend: class MockResend {
    emails = { send: mockSend };
  },
}));

import type { DailyEmailData } from "./email";
import { sendDailyEmail, sendPeriodConfirmationEmail } from "./email";

describe("sendDailyEmail", () => {
  afterEach(() => {
    vi.clearAllMocks();
  });

  const sampleData: DailyEmailData = {
    to: "user@example.com",
    cycleDay: 15,
    phase: "OVULATION",
    decision: {
      status: "TRAIN",
      reason: "Body battery high, HRV balanced - great day for training!",
      icon: "💪",
    },
    bodyBatteryCurrent: 85,
    bodyBatteryYesterdayLow: 45,
    hrvStatus: "Balanced",
    weekIntensity: 60,
    phaseLimit: 80,
    remainingMinutes: 20,
    seeds: "Sesame (1-2 tbsp) + Sunflower (1-2 tbsp)",
    carbRange: "100-150g",
    ketoGuidance: "No - exit keto, need carbs for ovulation",
  };

  it("sends email with correct subject line", async () => {
    await sendDailyEmail(sampleData);
    expect(mockSend).toHaveBeenCalledWith(
      expect.objectContaining({
        subject: "Today's Training: 💪 TRAIN",
      }),
    );
  });

  it("includes cycle day and phase in email body", async () => {
    await sendDailyEmail(sampleData);
    const call = mockSend.mock.calls[0][0];
    expect(call.text).toContain("📅 CYCLE DAY: 15 (OVULATION)");
  });

  it("includes decision icon and reason", async () => {
    await sendDailyEmail(sampleData);
    const call = mockSend.mock.calls[0][0];
    expect(call.text).toContain(
      "💪 Body battery high, HRV balanced - great day for training!",
    );
  });

  it("includes biometric data in email body", async () => {
    await sendDailyEmail(sampleData);
    const call = mockSend.mock.calls[0][0];
    expect(call.text).toContain("Body Battery Now: 85");
    expect(call.text).toContain("Yesterday's Low: 45");
    expect(call.text).toContain("HRV Status: Balanced");
    expect(call.text).toContain("Week Intensity: 60 / 80 minutes");
    expect(call.text).toContain("Remaining: 20 minutes");
  });

  it("includes nutrition guidance in email body", async () => {
    await sendDailyEmail(sampleData);
    const call = mockSend.mock.calls[0][0];
    expect(call.text).toContain(
      "🌱 SEEDS: Sesame (1-2 tbsp) + Sunflower (1-2 tbsp)",
    );
    expect(call.text).toContain("🍽️ MACROS: 100-150g");
    expect(call.text).toContain(
      "🥑 KETO: No - exit keto, need carbs for ovulation",
    );
  });

  it("handles null body battery values with N/A", async () => {
    const dataWithNulls: DailyEmailData = {
      ...sampleData,
      bodyBatteryCurrent: null,
      bodyBatteryYesterdayLow: null,
    };
    await sendDailyEmail(dataWithNulls);
    const call = mockSend.mock.calls[0][0];
    expect(call.text).toContain("Body Battery Now: N/A");
    expect(call.text).toContain("Yesterday's Low: N/A");
  });

  it("sends email to correct recipient", async () => {
    await sendDailyEmail(sampleData);
    expect(mockSend).toHaveBeenCalledWith(
      expect.objectContaining({
        to: "user@example.com",
      }),
    );
  });

  it("includes auto-generated footer", async () => {
    await sendDailyEmail(sampleData);
    const call = mockSend.mock.calls[0][0];
    expect(call.text).toContain("Auto-generated by PhaseFlow");
  });
});

describe("sendPeriodConfirmationEmail", () => {
  afterEach(() => {
    vi.clearAllMocks();
  });

  it("sends email with correct subject", async () => {
    await sendPeriodConfirmationEmail(
      "user@example.com",
      new Date("2025-01-15"),
      31,
    );
    expect(mockSend).toHaveBeenCalledWith(
      expect.objectContaining({
        subject: "🔵 Period Tracking Updated",
      }),
    );
  });

  it("includes last period date in body", async () => {
    await sendPeriodConfirmationEmail(
      "user@example.com",
      new Date("2025-01-15"),
      31,
    );
    const call = mockSend.mock.calls[0][0];
    // Date formatting depends on locale, so check for key parts
    expect(call.text).toContain("Your cycle has been reset");
    expect(call.text).toContain("Last period:");
  });

  it("includes cycle length in body", async () => {
    await sendPeriodConfirmationEmail(
      "user@example.com",
      new Date("2025-01-15"),
      28,
    );
    const call = mockSend.mock.calls[0][0];
    expect(call.text).toContain("Phase calendar updated for next 28 days");
  });

  it("sends to correct recipient", async () => {
    await sendPeriodConfirmationEmail(
      "test@example.com",
      new Date("2025-01-15"),
      31,
    );
    expect(mockSend).toHaveBeenCalledWith(
      expect.objectContaining({
        to: "test@example.com",
      }),
    );
  });

  it("includes auto-generated footer", async () => {
    await sendPeriodConfirmationEmail(
      "user@example.com",
      new Date("2025-01-15"),
      31,
    );
    const call = mockSend.mock.calls[0][0];
    expect(call.text).toContain("Auto-generated by PhaseFlow");
  });

  it("mentions calendar update timing", async () => {
    await sendPeriodConfirmationEmail(
      "user@example.com",
      new Date("2025-01-15"),
      31,
    );
    const call = mockSend.mock.calls[0][0];
    expect(call.text).toContain(
      "Your calendar will update automatically within 24 hours",
    );
  });
});