import { describe, it, expect } from "vitest";
import { groupByDate } from "../data/groupByDate";
import type { ConversationSummary } from "../data/types";

function makeConversation(id: string, daysAgo: number): ConversationSummary {
  const date = new Date();
  date.setDate(date.getDate() - daysAgo);
  date.setHours(10, 0, 0, 0);

  return {
    id,
    title: `Conversation ${id}`,
    createdAt: date.toISOString(),
    preview: "Preview text",
  };
}

describe("groupByDate", () => {
  it("groups conversations into Today", () => {
    const conversations = [makeConversation("1", 0), makeConversation("2", 0)];

    const result = groupByDate(conversations);

    expect(result).toHaveLength(1);
    expect(result[0].label).toBe("Today");
    expect(result[0].conversations).toHaveLength(2);
  });

  it("groups conversations into Yesterday", () => {
    const conversations = [makeConversation("1", 1)];

    const result = groupByDate(conversations);

    expect(result).toHaveLength(1);
    expect(result[0].label).toBe("Yesterday");
    expect(result[0].conversations).toHaveLength(1);
  });

  it("groups conversations into Last 7 days", () => {
    const conversations = [makeConversation("1", 3), makeConversation("2", 5)];

    const result = groupByDate(conversations);

    expect(result).toHaveLength(1);
    expect(result[0].label).toBe("Last 7 days");
    expect(result[0].conversations).toHaveLength(2);
  });

  it("groups conversations into Last 30 days", () => {
    const conversations = [
      makeConversation("1", 10),
      makeConversation("2", 20),
    ];

    const result = groupByDate(conversations);

    expect(result).toHaveLength(1);
    expect(result[0].label).toBe("Last 30 days");
    expect(result[0].conversations).toHaveLength(2);
  });

  it("groups conversations into Older", () => {
    const conversations = [makeConversation("1", 45)];

    const result = groupByDate(conversations);

    expect(result).toHaveLength(1);
    expect(result[0].label).toBe("Older");
  });

  it("filters out empty groups", () => {
    const conversations = [makeConversation("1", 0), makeConversation("2", 1)];

    const result = groupByDate(conversations);

    expect(result).toHaveLength(2);
    expect(result[0].label).toBe("Today");
    expect(result[1].label).toBe("Yesterday");
  });

  it("maintains group order regardless of input order", () => {
    const conversations = [makeConversation("2", 1), makeConversation("1", 0)];

    const result = groupByDate(conversations);

    expect(result[0].label).toBe("Today");
    expect(result[1].label).toBe("Yesterday");
  });

  it("returns empty array for no conversations", () => {
    const result = groupByDate([]);

    expect(result).toHaveLength(0);
  });

  it("groups all date ranges together", () => {
    const conversations = [
      makeConversation("today", 0),
      makeConversation("yesterday", 1),
      makeConversation("week", 3),
      makeConversation("month", 15),
      makeConversation("older", 50),
    ];

    const result = groupByDate(conversations);

    expect(result).toHaveLength(5);
    expect(result.map((g) => g.label)).toEqual([
      "Today",
      "Yesterday",
      "Last 7 days",
      "Last 30 days",
      "Older",
    ]);
  });
});