import { describe, expect, it } from "vitest";
import {
  errorMessage,
  formatRelativeTime,
  recencyGroup,
  titleFromPrompt,
  truncate,
} from "../lib/utils";

describe("truncate", () => {
  it("collapses whitespace so list rows never wrap unexpectedly", () => {
    expect(truncate("hello\n\n   world", 40)).toBe("hello world");
  });

  it("leaves short text alone", () => {
    expect(truncate("short", 40)).toBe("short");
  });

  it("clips with an ellipsis at the requested width", () => {
    const result = truncate("a".repeat(100), 10);
    expect(result).toBe(`${"a".repeat(9)}…`);
    expect(result).toHaveLength(10);
  });
});

describe("formatRelativeTime", () => {
  const now = 1_700_000_000_000;

  it("reports very recent timestamps as just now", () => {
    expect(formatRelativeTime(now - 5_000, now)).toBe("just now");
  });

  it("reports minutes and hours", () => {
    expect(formatRelativeTime(now - 12 * 60_000, now)).toBe("12m ago");
    expect(formatRelativeTime(now - 3 * 3_600_000, now)).toBe("3h ago");
  });

  it("reports days within the last week", () => {
    expect(formatRelativeTime(now - 2 * 86_400_000, now)).toBe("2d ago");
  });

  it("treats clock skew as just now rather than a negative age", () => {
    expect(formatRelativeTime(now + 60_000, now)).toBe("just now");
  });
});

describe("recencyGroup", () => {
  // Fixed local noon so the day boundaries are unambiguous on any machine.
  const now = new Date(2026, 9, 4, 12, 0, 0).getTime();
  const DAY = 86_400_000;

  it("buckets today", () => {
    expect(recencyGroup(now - 60_000, now)).toBe("Today");
  });

  it("buckets yesterday", () => {
    expect(recencyGroup(new Date(2026, 9, 3, 12, 0, 0).getTime(), now)).toBe("Yesterday");
  });

  it("buckets the rest of the week", () => {
    expect(recencyGroup(now - 3 * DAY, now)).toBe("This week");
    expect(recencyGroup(now - 6 * DAY, now)).toBe("This week");
  });

  it("buckets anything older", () => {
    expect(recencyGroup(now - 30 * DAY, now)).toBe("Older");
  });

  it("does not bucket the small hours of today as yesterday", () => {
    // Just after midnight is still today, even though it is under 24h ago.
    const justAfterMidnight = new Date(2026, 9, 4, 0, 5, 0).getTime();
    expect(recencyGroup(justAfterMidnight, now)).toBe("Today");
  });
});

describe("titleFromPrompt", () => {
  it("uses the first non-empty line, stripped of markdown decoration", () => {
    expect(titleFromPrompt("\n\n## How do I deploy?\nmore text", 60)).toBe("How do I deploy?");
  });

  it("falls back to a placeholder for an empty prompt", () => {
    expect(titleFromPrompt("   \n  ", 60)).toBe("New chat");
  });
});

describe("errorMessage", () => {
  it("unwraps Error instances", () => {
    expect(errorMessage(new Error("boom"))).toBe("boom");
  });

  it("passes strings through", () => {
    expect(errorMessage("plain failure")).toBe("plain failure");
  });

  it("survives values that cannot be serialised", () => {
    const circular: Record<string, unknown> = {};
    circular.self = circular;
    expect(typeof errorMessage(circular)).toBe("string");
  });
});