import { describe, it, expect, vi, beforeEach } from "vitest";
import { getCategoryOverTime } from "./reportService";

// Mock the db module
vi.mock("./db", () => ({
  getDb: vi.fn(),
}));

import { getDb } from "./db";

const mockSelect = vi.fn();
const mockDb = { select: mockSelect };

beforeEach(() => {
  vi.mocked(getDb).mockResolvedValue(mockDb as never);
  mockSelect.mockReset();
});

describe("getCategoryOverTime", () => {
  it("builds query without WHERE clause when no filters are provided", async () => {
    // First call: top categories, second call: monthly breakdown
    mockSelect
      .mockResolvedValueOnce([]) // topCategories
      .mockResolvedValueOnce([]); // monthlyRows

    await getCategoryOverTime();

    const topCatSQL = mockSelect.mock.calls[0][0] as string;
    // No WHERE clause should appear (no filters at all)
    expect(topCatSQL).not.toContain("WHERE");
  });

  it("applies typeFilter via category type when provided", async () => {
    mockSelect
      .mockResolvedValueOnce([]) // topCategories
      .mockResolvedValueOnce([]); // monthlyRows

    await getCategoryOverTime(undefined, undefined, 50, undefined, "expense");

    const topCatSQL = mockSelect.mock.calls[0][0] as string;
    const topCatParams = mockSelect.mock.calls[0][1] as unknown[];
    expect(topCatSQL).toContain("COALESCE(c.type, 'expense')");
    expect(topCatSQL).toContain("WHERE");
    expect(topCatParams[0]).toBe("expense");
  });

  it("applies income typeFilter correctly", async () => {
    mockSelect
      .mockResolvedValueOnce([]) // topCategories
      .mockResolvedValueOnce([]); // monthlyRows

    await getCategoryOverTime("2025-01-01", "2025-06-30", 50, undefined, "income");

    const topCatSQL = mockSelect.mock.calls[0][0] as string;
    const topCatParams = mockSelect.mock.calls[0][1] as unknown[];
    expect(topCatSQL).toContain("COALESCE(c.type, 'expense') = $1");
    expect(topCatParams[0]).toBe("income");
    // Date params follow
    expect(topCatParams[1]).toBe("2025-01-01");
    expect(topCatParams[2]).toBe("2025-06-30");
  });

  it("applies date range filters", async () => {
    mockSelect
      .mockResolvedValueOnce([]) // topCategories
      .mockResolvedValueOnce([]); // monthlyRows

    await getCategoryOverTime("2025-01-01", "2025-12-31");

    const topCatSQL = mockSelect.mock.calls[0][0] as string;
    const topCatParams = mockSelect.mock.calls[0][1] as unknown[];
    expect(topCatSQL).toContain("t.date >= $1");
    expect(topCatSQL).toContain("t.date <= $2");
    expect(topCatParams).toEqual(["2025-01-01", "2025-12-31", 50]);
  });

  it("applies sourceId filter", async () => {
    mockSelect
      .mockResolvedValueOnce([]) // topCategories
      .mockResolvedValueOnce([]); // monthlyRows

    await getCategoryOverTime(undefined, undefined, 50, 3);

    const topCatSQL = mockSelect.mock.calls[0][0] as string;
    const topCatParams = mockSelect.mock.calls[0][1] as unknown[];
    expect(topCatSQL).toContain("t.source_id");
    expect(topCatParams[0]).toBe(3);
  });

  it("combines typeFilter, date range, and sourceId", async () => {
    mockSelect
      .mockResolvedValueOnce([]) // topCategories
      .mockResolvedValueOnce([]); // monthlyRows

    await getCategoryOverTime("2025-01-01", "2025-06-30", 10, 2, "expense");

    const topCatSQL = mockSelect.mock.calls[0][0] as string;
    const topCatParams = mockSelect.mock.calls[0][1] as unknown[];
    expect(topCatSQL).toContain("COALESCE(c.type, 'expense') = $1");
    expect(topCatSQL).toContain("t.date >= $2");
    expect(topCatSQL).toContain("t.date <= $3");
    expect(topCatSQL).toContain("t.source_id = $4");
    expect(topCatParams).toEqual(["expense", "2025-01-01", "2025-06-30", 2, 10]);
  });

  it("returns correct structure with categories, data, colors, and categoryIds", async () => {
    mockSelect
      .mockResolvedValueOnce([
        { category_id: 1, category_name: "Food", category_color: "#ff0000", total: 500 },
        { category_id: 2, category_name: "Transport", category_color: "#00ff00", total: 200 },
      ])
      .mockResolvedValueOnce([
        { month: "2025-01", category_id: 1, category_name: "Food", total: 300 },
        { month: "2025-01", category_id: 2, category_name: "Transport", total: 100 },
        { month: "2025-02", category_id: 1, category_name: "Food", total: 200 },
        { month: "2025-02", category_id: 2, category_name: "Transport", total: 100 },
      ]);

    const result = await getCategoryOverTime("2025-01-01", "2025-02-28", 50, undefined, "expense");

    expect(result.categories).toEqual(["Food", "Transport"]);
    expect(result.colors).toEqual({ Food: "#ff0000", Transport: "#00ff00" });
    expect(result.categoryIds).toEqual({ Food: 1, Transport: 2 });
    expect(result.data).toHaveLength(2);
    expect(result.data[0]).toEqual({ month: "2025-01", Food: 300, Transport: 100 });
    expect(result.data[1]).toEqual({ month: "2025-02", Food: 200, Transport: 100 });
  });

  it("groups non-top-N categories into Other", async () => {
    mockSelect
      .mockResolvedValueOnce([
        { category_id: 1, category_name: "Food", category_color: "#ff0000", total: 500 },
      ])
      .mockResolvedValueOnce([
        { month: "2025-01", category_id: 1, category_name: "Food", total: 300 },
        { month: "2025-01", category_id: 2, category_name: "Transport", total: 100 },
        { month: "2025-01", category_id: 3, category_name: "Entertainment", total: 50 },
      ]);

    const result = await getCategoryOverTime("2025-01-01", "2025-01-31", 1, undefined, "expense");

    expect(result.categories).toEqual(["Food", "Other"]);
    expect(result.colors["Other"]).toBe("#9ca3af");
    expect(result.data[0]).toEqual({ month: "2025-01", Food: 300, Other: 150 });
  });
});