import { describe, expect, test } from "vitest";
import {
  decodePeachScript,
  encodePeachScript,
  isPeachScript,
  normalisePeachScript,
} from "./peachScript";

describe("peachScript", () => {
  test("byte 0 maps to U+E000", () => {
    const out = encodePeachScript(new Uint8Array([0]));
    expect(out.codePointAt(0)).toBe(0xe000);
  });

  test("byte 255 maps to U+E0FF", () => {
    const out = encodePeachScript(new Uint8Array([255]));
    expect(out.codePointAt(0)).toBe(0xe0ff);
  });

  test("round-trip identity for all 256 byte values", () => {
    const bytes = new Uint8Array(256);
    for (let i = 0; i < 256; i++) bytes[i] = i;
    const encoded = encodePeachScript(bytes);
    const decoded = decodePeachScript(encoded);
    expect(decoded).toEqual(bytes);
  });

  test("empty bytes round-trip to empty string and back", () => {
    expect(encodePeachScript(new Uint8Array())).toBe("");
    expect(decodePeachScript("")).toEqual(new Uint8Array());
  });

  test("decode throws on character outside PUA range", () => {
    expect(() => decodePeachScript("hello")).toThrow("INVALID_PEACHSCRIPT_CHARACTER");
    expect(() => decodePeachScript(String.fromCodePoint(0xe100))).toThrow(
      "INVALID_PEACHSCRIPT_CHARACTER"
    );
    expect(() => decodePeachScript(String.fromCodePoint(0xdfff))).toThrow(
      "INVALID_PEACHSCRIPT_CHARACTER"
    );
  });

  test("random-payload round-trip preserves bytes", () => {
    const payload = crypto.getRandomValues(new Uint8Array(2048));
    const decoded = decodePeachScript(encodePeachScript(payload));
    expect(decoded).toEqual(payload);
  });

  test("normalisePeachScript strips whitespace", () => {
    const encoded = encodePeachScript(new Uint8Array([1, 2, 3, 4]));
    const wrapped = encoded.slice(0, 2) + "\n  " + encoded.slice(2);
    expect(normalisePeachScript(wrapped)).toBe(encoded);
  });

  test("isPeachScript accepts only PUA strings", () => {
    expect(isPeachScript(encodePeachScript(new Uint8Array([1, 2, 3])))).toBe(true);
    expect(isPeachScript("")).toBe(false);
    expect(isPeachScript("hello")).toBe(false);
    const mixed = encodePeachScript(new Uint8Array([1])) + "x";
    expect(isPeachScript(mixed)).toBe(false);
  });
});