import { truncateToWidth, visibleWidth } from "@mariozechner/companion-tui";
import { describe, expect, it } from "vitest";

/**
 * Tests for truncateToWidth behavior with Unicode characters.
 *
 * These tests verify that truncateToWidth properly handles text with
 * Unicode characters that have different byte vs display widths.
 */
describe("truncateToWidth", () => {
  it("should truncate messages with Unicode characters correctly", () => {
    // This message contains a checkmark (✔) which may have display width > 1 byte
    const message =
      '✔ script to run › dev $ concurrently "vite" "node --import tsx ./';
    const width = 67;
    const maxMsgWidth = width - 2; // Account for cursor

    const truncated = truncateToWidth(message, maxMsgWidth);
    const truncatedWidth = visibleWidth(truncated);

    expect(truncatedWidth).toBeLessThanOrEqual(maxMsgWidth);
  });

  it("should handle emoji characters", () => {
    const message =
      "🎉 Celebration! 🚀 Launch 📦 Package ready for deployment now";
    const width = 40;
    const maxMsgWidth = width - 2;

    const truncated = truncateToWidth(message, maxMsgWidth);
    const truncatedWidth = visibleWidth(truncated);

    expect(truncatedWidth).toBeLessThanOrEqual(maxMsgWidth);
  });

  it("should handle mixed ASCII and wide characters", () => {
    const message = "Hello 世界 Test 你好 More text here that is long";
    const width = 30;
    const maxMsgWidth = width - 2;

    const truncated = truncateToWidth(message, maxMsgWidth);
    const truncatedWidth = visibleWidth(truncated);

    expect(truncatedWidth).toBeLessThanOrEqual(maxMsgWidth);
  });

  it("should not truncate messages that fit", () => {
    const message = "Short message";
    const width = 50;
    const maxMsgWidth = width - 2;

    const truncated = truncateToWidth(message, maxMsgWidth);

    expect(truncated).toBe(message);
    expect(visibleWidth(truncated)).toBeLessThanOrEqual(maxMsgWidth);
  });

  it("should add ellipsis when truncating", () => {
    const message = "This is a very long message that needs to be truncated";
    const width = 30;
    const maxMsgWidth = width - 2;

    const truncated = truncateToWidth(message, maxMsgWidth);

    expect(truncated).toContain("...");
    expect(visibleWidth(truncated)).toBeLessThanOrEqual(maxMsgWidth);
  });

  it("should handle the exact crash case from issue report", () => {
    // Terminal width was 67, line had visible width 68
    // The problematic text contained "✔" and "›" characters
    const message =
      '✔ script to run › dev $ concurrently "vite" "node --import tsx ./server.ts"';
    const terminalWidth = 67;
    const cursorWidth = 2; // "› " or "  "
    const maxMsgWidth = terminalWidth - cursorWidth;

    const truncated = truncateToWidth(message, maxMsgWidth);
    const finalWidth = visibleWidth(truncated);

    // The final line (cursor + message) must not exceed terminal width
    expect(finalWidth + cursorWidth).toBeLessThanOrEqual(terminalWidth);
  });
});