package mock

import "io"
import "time"
import "bytes"
import "git.tebibyte.media/sashakoshka/hopp"

var _ hopp.Trans = new(Trans)

// Trans is a mock transaction implementation.
type Trans struct {
	// These arrays must be the same length. You can load this up
	// with messages to read, or deposit messages and retrieve them
	// here later.
	Methods  []uint16
	Messages [][]byte
}

func (this *Trans) Close() error { return nil }

func (this *Trans) ID() int64 { return 56 }

func (this *Trans) Send(method uint16, data []byte) error {
	this.Methods  = append(this.Methods,  method)
	this.Messages = append(this.Messages, data)
	return nil
}

func (this *Trans) SendWriter(method uint16) (io.WriteCloser, error) {
	return &transWriter {
		Buffer: new(bytes.Buffer),
		method: method,
		parent: this,
	}, nil
}

func (this *Trans) Receive() (method uint16, data []byte, err error) {
	if len(this.Methods) == 0 {
		return 0, nil, io.EOF
	}
	method = this.Methods[0]
	data   = this.Messages[0]
	this.Methods  = this.Methods[1:]
	this.Messages = this.Messages[1:]
	return method, data, nil
}

func (this *Trans) ReceiveReader() (method uint16, reader io.Reader, err error) {
	method, data, err := this.Receive()
	if err != nil { return 0, nil, err }
	return method, bytes.NewBuffer(data), nil
}

func (this *Trans) SetDeadline(time.Time) error { return nil }

type transWriter struct {
	*bytes.Buffer
	method uint16
	parent *Trans
}

func (this *transWriter) Close() error {
	return this.parent.Send(this.method, this.Bytes())
}