import { createDecoder, peekUint8, peekUint16, peekUint32, peekVarInt, peekVarString, peekVarUint, readAny, readBigInt64, readBigUint64, readFloat32, readFloat64, readUint8, readUint16, readUint32, readUint32BigEndian, readVarInt, readVarString, readVarUint, readVarUint8Array } from './decoding'
import { createBinEncoder, writeAny, writeBigInt64, writeBigUint64, writeFloat32, writeFloat64, writeUint8, writeUint16, writeUint32, writeVarInt, writeVarString, writeVarUint, writeVarUint8Array } from './encoding'

describe('lib0/decoding', () => {
  it('should decode uint8/16/32', () => {
    const e = createBinEncoder()
    writeUint8(e, 255)
    writeUint16(e, 0x1234)
    writeUint32(e, 0x12345678)
    // writeUint32BigEndian(e, 0x12345678) // not needed for decoding test
    const arr = new Uint8Array(e.cbuf.buffer, 0, e.cpos)
    const d = createDecoder(arr)
    expect(readUint8(d)).toBe(255)
    expect(readUint16(d)).toBe(0x1234)
    expect(readUint32(d)).toBe(0x12345678)
    // readUint32BigEndian expects big-endian, but we didn't write any big-endian value, so expect 0
    expect(readUint32BigEndian(d)).toBe(0)
  })

  it('should decode varuint/varint', () => {
    const e = createBinEncoder()
    writeVarUint(e, 300)
    writeVarInt(e, -123)
    const arr = new Uint8Array(e.cbuf.buffer, 0, e.cpos)
    const d = createDecoder(arr)
    expect(readVarUint(d)).toBe(300)
    expect(readVarInt(d)).toBe(-123)
  })

  it('should decode strings and arrays', () => {
    const e = createBinEncoder()
    writeVarString(e, 'hello')
    writeVarUint8Array(e, new Uint8Array([1, 2, 3]))
    const arr = new Uint8Array(e.cbuf.buffer, 0, e.cpos)
    const d = createDecoder(arr)
    expect(readVarString(d)).toBe('hello')
    expect([...readVarUint8Array(d)]).toEqual([1, 2, 3])
  })

  it('should decode floats and bigints', () => {
    const e = createBinEncoder()
    writeFloat32(e, 1.5)
    writeFloat64(e, 2.5)
    writeBigInt64(e, BigInt(-123456789012345))
    writeBigUint64(e, BigInt(123456789012345))
    const arr = new Uint8Array(e.cbuf.buffer, 0, e.cpos)
    const d = createDecoder(arr)
    expect(readFloat32(d)).toBeCloseTo(1.5)
    expect(readFloat64(d)).toBeCloseTo(2.5)
    expect(readBigInt64(d)).toBe(BigInt(-123456789012345))
    expect(readBigUint64(d)).toBe(BigInt(123456789012345))
  })

  it('should decode any type', () => {
    const e = createBinEncoder()
    writeAny(e, undefined)
    writeAny(e, null)
    writeAny(e, 42)
    writeAny(e, 3.14)
    writeAny(e, BigInt(123))
    writeAny(e, true)
    writeAny(e, false)
    writeAny(e, 'str')
    writeAny(e, [1, 2, 3])
    writeAny(e, new Uint8Array([1, 2, 3]))
    writeAny(e, { a: 1, b: 2 })
    const arr = new Uint8Array(e.cbuf.buffer, 0, e.cpos)
    const d = createDecoder(arr)
    expect(readAny(d)).toBe(undefined)
    expect(readAny(d)).toBe(null)
    expect(readAny(d)).toBe(42)
    expect(readAny(d)).toBeCloseTo(3.14)
    expect(readAny(d)).toBe(BigInt(123))
    expect(readAny(d)).toBe(true)
    expect(readAny(d)).toBe(false)
    expect(readAny(d)).toBe('str')
    expect(readAny(d)).toEqual([1, 2, 3])
    expect([...readAny(d)]).toEqual([1, 2, 3])
    expect(readAny(d)).toEqual({ a: 1, b: 2 })
  })

  it('should peek values', () => {
    const e = createBinEncoder()
    writeUint8(e, 42)
    writeUint16(e, 0x1234)
    writeUint32(e, 0x12345678)
    writeVarUint(e, 300)
    writeVarInt(e, -123)
    writeVarString(e, 'peek')
    const arr = new Uint8Array(e.cbuf.buffer, 0, e.cpos)
    const d = createDecoder(arr)
    expect(peekUint8(d)).toBe(42)
    expect(readUint8(d)).toBe(42)
    expect(peekUint16(d)).toBe(0x1234)
    expect(readUint16(d)).toBe(0x1234)
    expect(peekUint32(d)).toBe(0x12345678)
    expect(readUint32(d)).toBe(0x12345678)
    expect(peekVarUint(d)).toBe(300)
    expect(readVarUint(d)).toBe(300)
    expect(peekVarInt(d)).toBe(-123)
    expect(readVarInt(d)).toBe(-123)
    expect(peekVarString(d)).toBe('peek')
    expect(readVarString(d)).toBe('peek')
  })
})