package zsocket

import (

"compress/flate"

"errors"

"time"

)

// ==============================

// Public message & close types

// ==============================

// MessageType represents the WebSocket message type.

type MessageType byte

const (

TextMessage MessageType = 1

BinaryMessage MessageType = 2

CloseMessage MessageType = 8

PingMessage MessageType = 9

PongMessage MessageType = 10

)

// CloseCode follows RFC 6455 close codes (select common ones here).

type CloseCode uint16

const (

CloseNormalClosure CloseCode = 1000

CloseGoingAway CloseCode = 1001

CloseProtocolError CloseCode = 1002

CloseUnsupportedData CloseCode = 1003

CloseNoStatusRcvd CloseCode = 1005 // reserved - do not send

CloseNoStatusReceived CloseCode = CloseNoStatusRcvd

CloseAbnormalClosure CloseCode = 1006 // reserved - do not send

CloseInvalidFramePayloadData CloseCode = 1007

ClosePolicyViolation CloseCode = 1008

CloseMessageTooBig CloseCode = 1009

CloseMandatoryExtension CloseCode = 1010

CloseInternalServerErr CloseCode = 1011

CloseTLSHandshake CloseCode = 1015

)

// ==============================

// Config

// ==============================

// Config controls WebSocket server behavior during handshake and runtime.

type Config struct {

// AllowedOrigins is used to check request Origin. Empty means "allow all".

AllowedOrigins []string

// Subprotocols contains allowed subprotocol names.

Subprotocols []string

// HandshakeTimeout controls the HTTP upgrade deadline.

HandshakeTimeout time.Duration

// ReadLimit caps the maximum message payload (bytes). 0 means no limit.

ReadLimit int64

// ReadBufferSize / WriteBufferSize are used for buffered I/O.

ReadBufferSize int

WriteBufferSize int

// PingInterval sets how often to send pings. 0 disables keepalive pings.

PingInterval time.Duration

// PongWait is how long to wait for a pong after a ping. Must be > 0 if PingInterval > 0.

PongWait time.Duration

// WriteTimeout caps write operations (frames & control frames).

WriteTimeout time.Duration

// CheckOrigin allows custom origin validation. If set, overrides AllowedOrigins.

CheckOrigin func(origin string) bool

// Logger is optional. If nil, logging is no-op.

Logger Logger

// EnableCompression enables per-message deflate negotiation.

EnableCompression bool

// CompressionLevel controls flate level when compression is enabled.

CompressionLevel int

// WriteBufferPool optionally provides reusable write buffers.

WriteBufferPool BufferPool

}

// DefaultConfig returns a practical default config for servers.

func DefaultConfig() Config {

return Config{

AllowedOrigins: nil,

Subprotocols: nil,

HandshakeTimeout: 5 * time.Second,

ReadLimit: 16 << 20, // 16 MiB

ReadBufferSize: 4096,

WriteBufferSize: 4096,

PingInterval: 30 * time.Second,

PongWait: 15 * time.Second,

WriteTimeout: 10 * time.Second,

Logger: NopLogger{},

CompressionLevel: flate.DefaultCompression,

}

}

// ==============================

// Logging interface

// ==============================

type Logger interface {

Debugf(format string, args ...any)

Infof(format string, args ...any)

Warnf(format string, args ...any)

Errorf(format string, args ...any)

}

type NopLogger struct{}

func (NopLogger) Debugf(string, ...any) {}

func (NopLogger) Infof(string, ...any) {}

func (NopLogger) Warnf(string, ...any) {}

func (NopLogger) Errorf(string, ...any) {}

// ==============================

// Public errors

// ==============================

var (

ErrBadRequest = errors.New("zsocket: bad websocket upgrade request")

ErrHandshakeFailed = errors.New("zsocket: handshake failed")

ErrOriginNotAllowed = errors.New("zsocket: origin not allowed")

ErrSubprotocolRejected = errors.New("zsocket: subprotocol rejected")

ErrClosed = errors.New("zsocket: connection closed")

ErrTimeout = errors.New("zsocket: timeout")

)