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

vi.mock("@/lib/db", () => {
  const monthlyInsight = {
    upsert: vi.fn(async ({ where, update, create }: { where: { month: string }; update: Record<string, unknown>; create: Record<string, unknown> }) => ({
      id: "insight-1",
      month: where.month,
      year: (update.year ?? create.year) as number,
      summary: (update.summary ?? create.summary) as string,
      recommendations: (update.recommendations ?? create.recommendations) as string,
      inputSnapshot: (update.inputSnapshot ?? create.inputSnapshot) as string,
      generatedAt: new Date("2026-03-23T12:00:00.000Z"),
    })),
    findUnique: vi.fn(),
  };

  return {
    db: {
      expense: { findMany: vi.fn() },
      paycheck: { findMany: vi.fn() },
      recurringExpense: { findMany: vi.fn().mockResolvedValue([]) },
      paySchedule: { findFirst: vi.fn().mockResolvedValue(null) },
      monthlyInsight,
    },
  };
});

describe("generateMonthlyInsight", () => {
  afterEach(() => {
    vi.restoreAllMocks();
  });

  it("stores a fallback for sparse months", async () => {
    const { db } = await import("@/lib/db");
    const { generateMonthlyInsight } = await import("@/lib/insights");

    vi.mocked(db.expense.findMany).mockResolvedValue([]);
    vi.mocked(db.paycheck.findMany).mockResolvedValue([]);
    vi.mocked(db.recurringExpense.findMany).mockResolvedValue([]);

    const result = await generateMonthlyInsight("2026-03");

    expect(result.source).toBe("fallback");
    expect(result.insight.summary).toContain("not enough activity");
  });

  it("stores model output when Ollama responds", async () => {
    const { db } = await import("@/lib/db");
    const { generateMonthlyInsight } = await import("@/lib/insights");

    vi.mocked(db.expense.findMany).mockResolvedValue([
      {
        id: "expense-1",
        title: "Groceries",
        date: "2026-03-23",
        amountCents: 3200,
        category: "FOOD",
        createdAt: new Date("2026-03-23T10:00:00.000Z"),
      },
      {
        id: "expense-2",
        title: "Rent",
        date: "2026-03-02",
        amountCents: 120000,
        category: "RENT",
        createdAt: new Date("2026-03-02T10:00:00.000Z"),
      },
    ]);
    vi.mocked(db.paycheck.findMany).mockResolvedValue([
      {
        id: "paycheck-1",
        payDate: "2026-03-01",
        amountCents: 180000,
        createdAt: new Date("2026-03-01T10:00:00.000Z"),
      },
    ]);
    vi.mocked(db.recurringExpense.findMany).mockResolvedValue([]);

    vi.spyOn(globalThis, "fetch").mockResolvedValue({
      ok: true,
      json: async () => ({
        response: JSON.stringify({
          summary: "Spending is stable.",
          recommendations: "Keep food spending under watch.",
        }),
      }),
    } as Response);

    const result = await generateMonthlyInsight("2026-03");

    expect(result.source).toBe("model");
    expect(result.insight.summary).toBe("Spending is stable.");
    expect(result.insight.recommendations).toBe('["Keep food spending under watch."]');
  });

  it("coerces array recommendations from the local model", async () => {
    const { db } = await import("@/lib/db");
    const { generateMonthlyInsight } = await import("@/lib/insights");

    vi.mocked(db.expense.findMany).mockResolvedValue([
      {
        id: "expense-1",
        title: "Groceries",
        date: "2026-03-23",
        amountCents: 3200,
        category: "FOOD",
        createdAt: new Date("2026-03-23T10:00:00.000Z"),
      },
      {
        id: "expense-2",
        title: "Rent",
        date: "2026-03-02",
        amountCents: 120000,
        category: "RENT",
        createdAt: new Date("2026-03-02T10:00:00.000Z"),
      },
    ]);
    vi.mocked(db.paycheck.findMany).mockResolvedValue([
      {
        id: "paycheck-1",
        payDate: "2026-03-01",
        amountCents: 180000,
        createdAt: new Date("2026-03-01T10:00:00.000Z"),
      },
    ]);
    vi.mocked(db.recurringExpense.findMany).mockResolvedValue([]);

    vi.spyOn(globalThis, "fetch").mockResolvedValue({
      ok: true,
      json: async () => ({
        response: JSON.stringify({
          summary: "Spending remains manageable.",
          recommendations: ["Keep groceries planned.", "Move surplus to savings."],
        }),
      }),
    } as Response);

    const result = await generateMonthlyInsight("2026-03");

    expect(result.insight.recommendations).toContain("Keep groceries planned.");
    expect(result.insight.recommendations).toContain("Move surplus to savings.");
  });
});