soju/irc.go
2023-03-01 13:52:33 +01:00

277 lines
6.3 KiB
Go

package soju
import (
"fmt"
"strings"
"time"
"unicode"
"unicode/utf8"
"gopkg.in/irc.v4"
"git.sr.ht/~emersion/soju/xirc"
)
// TODO: generalize and move helpers to the xirc package
type userModes string
func (ms userModes) Has(c byte) bool {
return strings.IndexByte(string(ms), c) >= 0
}
func (ms *userModes) Add(c byte) {
if !ms.Has(c) {
*ms += userModes(c)
}
}
func (ms *userModes) Del(c byte) {
i := strings.IndexByte(string(*ms), c)
if i >= 0 {
*ms = (*ms)[:i] + (*ms)[i+1:]
}
}
func (ms *userModes) Apply(s string) error {
var plusMinus byte
for i := 0; i < len(s); i++ {
switch c := s[i]; c {
case '+', '-':
plusMinus = c
default:
switch plusMinus {
case '+':
ms.Add(c)
case '-':
ms.Del(c)
default:
return fmt.Errorf("malformed modestring %q: missing plus/minus", s)
}
}
}
return nil
}
type channelModeType byte
// standard channel mode types, as explained in https://modern.ircdocs.horse/#mode-message
const (
// modes that add or remove an address to or from a list
modeTypeA channelModeType = iota
// modes that change a setting on a channel, and must always have a parameter
modeTypeB
// modes that change a setting on a channel, and must have a parameter when being set, and no parameter when being unset
modeTypeC
// modes that change a setting on a channel, and must not have a parameter
modeTypeD
)
var stdChannelModes = map[byte]channelModeType{
'b': modeTypeA, // ban list
'e': modeTypeA, // ban exception list
'I': modeTypeA, // invite exception list
'k': modeTypeB, // channel key
'l': modeTypeC, // channel user limit
'i': modeTypeD, // channel is invite-only
'm': modeTypeD, // channel is moderated
'n': modeTypeD, // channel has no external messages
's': modeTypeD, // channel is secret
't': modeTypeD, // channel has protected topic
}
type channelModes map[byte]string
// applyChannelModes parses a mode string and mode arguments from a MODE message,
// and applies the corresponding channel mode and user membership changes on that channel.
//
// If ch.modes is nil, channel modes are not updated.
func applyChannelModes(ch *upstreamChannel, modeStr string, arguments []string) error {
nextArgument := 0
var plusMinus byte
outer:
for i := 0; i < len(modeStr); i++ {
mode := modeStr[i]
if mode == '+' || mode == '-' {
plusMinus = mode
continue
}
if plusMinus != '+' && plusMinus != '-' {
return fmt.Errorf("malformed modestring %q: missing plus/minus", modeStr)
}
for _, membership := range ch.conn.availableMemberships {
if membership.Mode == mode {
if nextArgument >= len(arguments) {
return fmt.Errorf("malformed modestring %q: missing mode argument for %c%c", modeStr, plusMinus, mode)
}
member := arguments[nextArgument]
m := ch.Members.Get(member)
if m != nil {
if plusMinus == '+' {
m.Add(ch.conn.availableMemberships, membership)
} else {
// TODO: for upstreams without multi-prefix, query the user modes again
m.Remove(membership)
}
}
nextArgument++
continue outer
}
}
mt, ok := ch.conn.availableChannelModes[mode]
if !ok {
continue
}
if mt == modeTypeA {
nextArgument++
} else if mt == modeTypeB || (mt == modeTypeC && plusMinus == '+') {
if plusMinus == '+' {
var argument string
// some sentitive arguments (such as channel keys) can be omitted for privacy
// (this will only happen for RPL_CHANNELMODEIS, never for MODE messages)
if nextArgument < len(arguments) {
argument = arguments[nextArgument]
}
if ch.modes != nil {
ch.modes[mode] = argument
}
} else {
delete(ch.modes, mode)
}
nextArgument++
} else if mt == modeTypeC || mt == modeTypeD {
if plusMinus == '+' {
if ch.modes != nil {
ch.modes[mode] = ""
}
} else {
delete(ch.modes, mode)
}
}
}
return nil
}
func (cm channelModes) Format() (modeString string, parameters []string) {
var modesWithValues strings.Builder
var modesWithoutValues strings.Builder
parameters = make([]string, 0, 16)
for mode, value := range cm {
if value != "" {
modesWithValues.WriteString(string(mode))
parameters = append(parameters, value)
} else {
modesWithoutValues.WriteString(string(mode))
}
}
modeString = "+" + modesWithValues.String() + modesWithoutValues.String()
return
}
const stdChannelTypes = "#&+!"
var stdMemberships = []xirc.Membership{
{'q', '~'}, // founder
{'a', '&'}, // protected
{'o', '@'}, // operator
{'h', '%'}, // halfop
{'v', '+'}, // voice
}
func formatMemberPrefix(ms xirc.MembershipSet, dc *downstreamConn) string {
if !dc.caps.IsEnabled("multi-prefix") {
if len(ms) == 0 {
return ""
}
return string(ms[0].Prefix)
}
prefixes := make([]byte, len(ms))
for i, m := range ms {
prefixes[i] = m.Prefix
}
return string(prefixes)
}
func parseMessageParams(msg *irc.Message, out ...*string) error {
if len(msg.Params) < len(out) {
return newNeedMoreParamsError(msg.Command)
}
for i := range out {
if out[i] != nil {
*out[i] = msg.Params[i]
}
}
return nil
}
func copyClientTags(tags irc.Tags) irc.Tags {
t := make(irc.Tags, len(tags))
for k, v := range tags {
if strings.HasPrefix(k, "+") {
t[k] = v
}
}
return t
}
var stdCaseMapping = xirc.CaseMappingRFC1459
func isWordBoundary(r rune) bool {
switch r {
case '-', '_', '|': // inspired from weechat.look.highlight_regex
return false
default:
return !unicode.IsLetter(r) && !unicode.IsNumber(r)
}
}
func isHighlight(text, nick string) bool {
for {
i := strings.Index(text, nick)
if i < 0 {
return false
}
left, _ := utf8.DecodeLastRuneInString(text[:i])
right, _ := utf8.DecodeRuneInString(text[i+len(nick):])
if isWordBoundary(left) && isWordBoundary(right) {
return true
}
text = text[i+len(nick):]
}
}
// parseChatHistoryBound parses the given CHATHISTORY parameter as a bound.
// The zero time is returned on error.
func parseChatHistoryBound(param string) time.Time {
parts := strings.SplitN(param, "=", 2)
if len(parts) != 2 {
return time.Time{}
}
switch parts[0] {
case "timestamp":
timestamp, err := time.Parse(xirc.ServerTimeLayout, parts[1])
if err != nil {
return time.Time{}
}
return timestamp
default:
return time.Time{}
}
}
func isNumeric(cmd string) bool {
if len(cmd) != 3 {
return false
}
for i := 0; i < 3; i++ {
if cmd[i] < '0' || cmd[i] > '9' {
return false
}
}
return true
}