numeric.js

const { PartialReadError, Result } = require('../../utils')

function readI64 (buffer, offset) {
  if (offset + 8 > buffer.length) { throw new PartialReadError() }
  return new Result([buffer.readInt32BE(offset), buffer.readInt32BE(offset + 4)], 8)
}

function writeI64 (value, buffer, offset) {
  buffer.writeInt32BE(value[0], offset)
  buffer.writeInt32BE(value[1], offset + 4)
  return offset + 8
}

function readLI64 (buffer, offset) {
  if (offset + 8 > buffer.length) { throw new PartialReadError() }
  return new Result([buffer.readInt32LE(offset + 4), buffer.readInt32LE(offset)], 8)
}

function writeLI64 (value, buffer, offset) {
  buffer.writeInt32LE(value[0], offset + 4)
  buffer.writeInt32LE(value[1], offset)
  return offset + 8
}

function readU64 (buffer, offset) {
  if (offset + 8 > buffer.length) { throw new PartialReadError() }
  return new Result([buffer.readUInt32BE(offset), buffer.readUInt32BE(offset + 4)], 8)
}

function writeU64 (value, buffer, offset) {
  buffer.writeUInt32BE(value[0], offset)
  buffer.writeUInt32BE(value[1], offset + 4)
  return offset + 8
}

function readLU64 (buffer, offset) {
  if (offset + 8 > buffer.length) { throw new PartialReadError() }
  return new Result([buffer.readUInt32LE(offset + 4), buffer.readUInt32LE(offset)], 8)
}

function writeLU64 (value, buffer, offset) {
  buffer.writeUInt32LE(value[0], offset + 4)
  buffer.writeUInt32LE(value[1], offset)
  return offset + 8
}

const nums = {
  'i8': ['readInt8', 'writeInt8', 1],
  'u8': ['readUInt8', 'writeUInt8', 1],
  'i16': ['readInt16BE', 'writeInt16BE', 2],
  'u16': ['readUInt16BE', 'writeUInt16BE', 2],
  'i32': ['readInt32BE', 'writeInt32BE', 4],
  'u32': ['readUInt32BE', 'writeUInt32BE', 4],
  'f32': ['readFloatBE', 'writeFloatBE', 4],
  'f64': ['readDoubleBE', 'writeDoubleBE', 8],
  'li8': ['readInt8', 'writeInt8', 1],
  'lu8': ['readUInt8', 'writeUInt8', 1],
  'li16': ['readInt16LE', 'writeInt16LE', 2],
  'lu16': ['readUInt16LE', 'writeUInt16LE', 2],
  'li32': ['readInt32LE', 'writeInt32LE', 4],
  'lu32': ['readUInt32LE', 'writeUInt32LE', 4],
  'lf32': ['readFloatLE', 'writeFloatLE', 4],
  'lf64': ['readDoubleLE', 'writeDoubleLE', 8]
}

const types = {
  i64: [readI64, writeI64, 8, require('../../../ProtoDef/schemas/numeric.json')['i64']],
  li64: [readLI64, writeLI64, 8, require('../../../ProtoDef/schemas/numeric.json')['li64']],
  u64: [readU64, writeU64, 8, require('../../../ProtoDef/schemas/numeric.json')['u64']],
  lu64: [readLU64, writeLU64, 8, require('../../../ProtoDef/schemas/numeric.json')['lu64']]
}

function readIntN (method, size, buffer, offset) {
  if (offset + size > buffer.length) throw new PartialReadError()
  return new Result(buffer[method](offset), size)
}

function writeIntN (method, value, buffer, offset) {
  return buffer[method](value, offset)
}

for (const num in nums) {
  const [ bufferReader, bufferWriter, size ] = nums[num]
  types[num] = [
    readIntN.bind(null, bufferReader, size),
    writeIntN.bind(null, bufferWriter),
    size,
    require('../../../ProtoDef/schemas/numeric.json')[num]
  ]
}

module.exports = types