import { describe, it, expect } from 'vitest'
import {
  encodeBase64,
  decodeBase64,
  encodeUrl,
  decodeUrl,
  encodeUnicode,
  decodeUnicode,
  bytesToBase64,
  base64ToBytes,
} from '../../src/utils/encoder.js'
import { zlibSync, decompressSync } from 'fflate'

describe('encoder', () => {
  describe('base64', () => {
    it('encodes and decodes ASCII text', () => {
      expect(decodeBase64(encodeBase64('hello'))).toBe('hello')
    })

    it('encodes and decodes unicode text', () => {
      const text = '你好世界'
      expect(decodeBase64(encodeBase64(text))).toBe(text)
    })
  })

  describe('url', () => {
    it('encodes and decodes URL components', () => {
      expect(decodeUrl(encodeUrl('a b&c=1'))).toBe('a b&c=1')
    })
  })

  describe('unicode escape', () => {
    it('encodes BMP characters', () => {
      expect(encodeUnicode('A')).toBe('\\u0041')
    })

    it('roundtrips BMP text', () => {
      expect(decodeUnicode('\\u0048\\u0065\\u006C\\u006C\\u006F')).toBe('Hello')
    })

    it('encodes and decodes emoji (surrogate pair)', () => {
      const emoji = '😀'
      const encoded = encodeUnicode(emoji)
      expect(decodeUnicode(encoded)).toBe(emoji)
    })

    it('decodes \\UXXXXXXXX format', () => {
      expect(decodeUnicode('\\U0001F600')).toBe('😀')
    })

    it('throws on invalid unicode code point', () => {
      expect(() => decodeUnicode('\\U00110000')).toThrow('Unicode 解码失败')
    })
  })

  describe('binary helpers', () => {
    it('roundtrips bytes through base64', () => {
      const bytes = new Uint8Array([1, 2, 3, 255])
      expect([...base64ToBytes(bytesToBase64(bytes))]).toEqual([...bytes])
    })

    it('strips whitespace when decoding base64', () => {
      const bytes = new Uint8Array([72, 101, 108, 108, 111])
      expect(new TextDecoder().decode(base64ToBytes('SGVs\nbG8='))).toBe('Hello')
    })
  })

  describe('zlib roundtrip', () => {
    it('compresses and decompresses text', () => {
      const text = 'hello zlib compression test'
      const compressed = zlibSync(new TextEncoder().encode(text))
      const b64 = bytesToBase64(compressed)
      const decompressed = new TextDecoder().decode(decompressSync(base64ToBytes(b64)))
      expect(decompressed).toBe(text)
    })
  })
})