package session

import (
    "net"
    "ripple/handler"
    "ripple/transport"
    "ripple/types"
)

type UserSession struct {
	transport   *transport.UserTransport
    cmdHandlers [256]func(types.ClientRemote, []byte) (byte, []byte)
}

func NewUserSession(
    transport *transport.UserTransport, 
    h *handler.UserHandlers,
) *UserSession {
    s := &UserSession{transport: transport}

    s.cmdHandlers[0x00] = h.AddAccount
    s.cmdHandlers[0x01] = h.SetTrustline
    s.cmdHandlers[0x02] = h.NewPayment
    s.cmdHandlers[0x03] = h.StartPayment

    return s
}

func (s *UserSession) Receive(tx []byte, addr *net.UDPAddr) (types.UserRequest, error) {
    return s.transport.Receive(tx, addr)
}

func (s *UserSession) Dispatch(req types.UserRequest) {
    remote := req.Remote
    h := s.cmdHandlers[req.Instruction.Command]
    if h == nil {
        s.transport.Send(handlerErrorResponse(remote))
        return
    }
    status, msg := h(remote, req.Instruction.Arguments)
    s.transport.Send(buildClientResponse(remote, status, msg))
}

func buildClientResponse(r types.ClientRemote, status byte, msg []byte) types.UserRequest {
    return types.UserRequest{
        Remote: r,
        Instruction: types.Instruction{
            Command:   status,
            Arguments: msg,
        },
    }
}

func handlerErrorResponse(r types.ClientRemote) types.UserRequest {
    return buildClientResponse(r, 0x01, []byte("invalid command"))
}