/*  This is a jsig notation of your interface.
    https://github.com/jsigbiz/spec
*/

type ValueConstructor : () => value

type LengthResult: {
  err: null|Error,
  length: Number
}

type WriteResult: {
  err: null|Error,
  offset: Number
}

type ReadResult: {
  err: null|Error,
  offset: Number,
  value: null|Object
}

type BufferRW : {
  byteLength: (value) => LengthResult
  writeInto: (value, buffer, offset) => WriteResult
  readFrom: (buffer, offset) => ReadResult
}

type structFieldSpecs : Array<structFieldSpec> | Object<name,structFieldSpec>

type structFieldSpec : {
    name : ?String,
    rw : ?BufferRW
    call : ?{
        byteLength: (obj, value) => LengthResult
        writeInto: (obj, buffer, offset) => WriteResult
        readFrom: (obj, buffer, offset) => ReadResult
    }
}

type structOptions : {
    readGuard : (obj) => null|Error
    writeGuard : (obj) => null|Error
}

bufrw : {
    toBuffer: (BufferRW, value) => Buffer
    fromBuffer: (BufferRW, Buffer, offset?:Number) => value

    Base : (byteLength, writeInto, readFrom) => BufferRW

    LengthResult : {
        just: (length:Number) => LengthResult
        error: (err:Error, length:Number) => LengthResult
    }

    WriteResult : {
        just: (offset:Number) => WriteResult
        error: (err:Error, offset:Number) => WriteResult
    }

    ReadResult : {
        just: (offset:Number, value) => ReadResult
        error: (err:Error, offset:Number, value) => ReadResult
    }

    UInt8 : BufferRW
    UInt16BE : BufferRW
    UInt32BE : BufferRW
    Null : BufferRW

    FixedWidth : (length:Number, ?readFrom, ?writeInto) => BufferRW
    Skip : (length:Number, fill:Number) => BufferRW

    VariableBuffer : (size:Number, {encoding:String, autoDecode:Boolean}) => BufferRW
    buf1 : BufferRW
    buf2 : BufferRW
    str1 : BufferRW
    str2 : BufferRW

    Series : (Array<BufferRW>) => BufferRW
    Struct : (cons:ValueConstructor, fields:structFieldSpec, options:structOptions) => BufferRW
    Switch : (valrw:BufferRW, cases:Map<val,BufferRW>, ?opts:{valKey?:String, dataKey?:String}) => BufferRW
    Repeat : (countrw:BufferRW, repeatedrw:BufferRW) => BufferRW
}