irc: Move everything from lindenii-irc

7 files changed, 235 insertions, 6 deletions

diff --git a/forged/internal/irc/bot.go b/forged/internal/irc/bot.go
index 046799f..1c6d32f 100644
--- a/forged/internal/irc/bot.go
+++ b/forged/internal/irc/bot.go
@@ -10,7 +10,6 @@ import (
 	"net"
 
 	"go.lindenii.runxiyu.org/forge/forged/internal/misc"
-	irc "go.lindenii.runxiyu.org/lindenii-irc"
 )
 
 // Config contains IRC connection and identity settings for the bot.
@@ -55,7 +54,7 @@ func (b *Bot) Connect() error {
 	}
 	defer underlyingConn.Close()
 
-	conn := irc.NewConn(underlyingConn)
+	conn := NewConn(underlyingConn)
 
 	logAndWriteLn := func(s string) (n int, err error) {
 		slog.Debug("irc tx", "line", s)
@@ -103,7 +102,7 @@ func (b *Bot) Connect() error {
 					return
 				}
 			case "JOIN":
-				c, ok := msg.Source.(irc.Client)
+				c, ok := msg.Source.(Client)
 				if !ok {
 					slog.Error("unable to convert source of JOIN to client")
 				}
diff --git a/forged/internal/irc/conn.go b/forged/internal/irc/conn.go
new file mode 100644
index 0000000..b975b72
--- /dev/null
+++ b/forged/internal/irc/conn.go
@@ -0,0 +1,49 @@
+package irc
+
+import (
+	"bufio"
+	"net"
+	"slices"
+
+	"go.lindenii.runxiyu.org/forge/forged/internal/misc"
+)
+
+type Conn struct {
+	netConn   net.Conn
+	bufReader *bufio.Reader
+}
+
+func NewConn(netConn net.Conn) Conn {
+	return Conn{
+		netConn:   netConn,
+		bufReader: bufio.NewReader(netConn),
+	}
+}
+
+func (c *Conn) ReadMessage() (msg Message, line string, err error) {
+	raw, err := c.bufReader.ReadSlice('\n')
+	if err != nil {
+		return
+	}
+
+	if raw[len(raw)-1] == '\n' {
+		raw = raw[:len(raw)-1]
+	}
+	if raw[len(raw)-1] == '\r' {
+		raw = raw[:len(raw)-1]
+	}
+
+	lineBytes := slices.Clone(raw)
+	line = misc.BytesToString(lineBytes)
+	msg, err = Parse(lineBytes)
+
+	return
+}
+
+func (c *Conn) Write(p []byte) (n int, err error) {
+	return c.netConn.Write(p)
+}
+
+func (c *Conn) WriteString(s string) (n int, err error) {
+	return c.netConn.Write(misc.StringToBytes(s))
+}
diff --git a/forged/internal/irc/errors.go b/forged/internal/irc/errors.go
new file mode 100644
index 0000000..3506c70
--- /dev/null
+++ b/forged/internal/irc/errors.go
@@ -0,0 +1,8 @@
+package irc
+
+import "errors"
+
+var (
+	ErrInvalidIRCv3Tag = errors.New("invalid ircv3 tag")
+	ErrMalformedMsg    = errors.New("malformed irc message")
+)
diff --git a/forged/internal/irc/message.go b/forged/internal/irc/message.go
new file mode 100644
index 0000000..84b6867
--- /dev/null
+++ b/forged/internal/irc/message.go
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: MIT
+// SPDX-FileCopyrightText: Copyright (c) 2018-2024 luk3yx <https://luk3yx.github.io>
+// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>
+
+package irc
+
+import (
+	"bytes"
+
+	"go.lindenii.runxiyu.org/forge/forged/internal/misc"
+)
+
+type Message struct {
+	Command string
+	Source  Source
+	Tags    map[string]string
+	Args    []string
+}
+
+// All strings returned are borrowed from the input byte slice.
+func Parse(raw []byte) (msg Message, err error) {
+	sp := bytes.Split(raw, []byte{' '}) // TODO: Use bytes.Cut instead here
+
+	if bytes.HasPrefix(sp[0], []byte{'@'}) { // TODO: Check size manually
+		if len(sp[0]) < 2 {
+			err = ErrMalformedMsg
+			return
+		}
+		sp[0] = sp[0][1:]
+
+		msg.Tags, err = tagsToMap(sp[0])
+		if err != nil {
+			return
+		}
+
+		if len(sp) < 2 {
+			err = ErrMalformedMsg
+			return
+		}
+		sp = sp[1:]
+	} else {
+		msg.Tags = nil // TODO: Is a nil map the correct thing to use here?
+	}
+
+	if bytes.HasPrefix(sp[0], []byte{':'}) { // TODO: Check size manually
+		if len(sp[0]) < 2 {
+			err = ErrMalformedMsg
+			return
+		}
+		sp[0] = sp[0][1:]
+
+		msg.Source = parseSource(sp[0])
+
+		if len(sp) < 2 {
+			err = ErrMalformedMsg
+			return
+		}
+		sp = sp[1:]
+	}
+
+	msg.Command = misc.BytesToString(sp[0])
+	if len(sp) < 2 {
+		return
+	}
+	sp = sp[1:]
+
+	for i := 0; i < len(sp); i++ {
+		if len(sp[i]) == 0 {
+			continue
+		}
+		if sp[i][0] == ':' {
+			if len(sp[i]) < 2 {
+				sp[i] = []byte{}
+			} else {
+				sp[i] = sp[i][1:]
+			}
+			msg.Args = append(msg.Args, misc.BytesToString(bytes.Join(sp[i:], []byte{' '})))
+			// TODO: Avoid Join by not using sp in the first place
+			break
+		}
+		msg.Args = append(msg.Args, misc.BytesToString(sp[i]))
+	}
+
+	return
+}
+
+var ircv3TagEscapes = map[byte]byte{ //nolint:gochecknoglobals
+	':': ';',
+	's': ' ',
+	'r': '\r',
+	'n': '\n',
+}
+
+func tagsToMap(raw []byte) (tags map[string]string, err error) {
+	tags = make(map[string]string)
+	for rawTag := range bytes.SplitSeq(raw, []byte{';'}) {
+		key, value, found := bytes.Cut(rawTag, []byte{'='})
+		if !found {
+			err = ErrInvalidIRCv3Tag
+			return
+		}
+		if len(value) == 0 {
+			tags[misc.BytesToString(key)] = ""
+		} else {
+			if !bytes.Contains(value, []byte{'\\'}) {
+				tags[misc.BytesToString(key)] = misc.BytesToString(value)
+			} else {
+				valueUnescaped := bytes.NewBuffer(make([]byte, 0, len(value)))
+				for i := 0; i < len(value); i++ {
+					if value[i] == '\\' {
+						i++
+						byteUnescaped, ok := ircv3TagEscapes[value[i]]
+						if !ok {
+							byteUnescaped = value[i]
+						}
+						valueUnescaped.WriteByte(byteUnescaped)
+					} else {
+						valueUnescaped.WriteByte(value[i])
+					}
+				}
+				tags[misc.BytesToString(key)] = misc.BytesToString(valueUnescaped.Bytes())
+			}
+		}
+	}
+	return
+}
diff --git a/forged/internal/irc/source.go b/forged/internal/irc/source.go
new file mode 100644
index 0000000..d955f45
--- /dev/null
+++ b/forged/internal/irc/source.go
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: MIT
+// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>
+
+package irc
+
+import (
+	"bytes"
+
+	"go.lindenii.runxiyu.org/forge/forged/internal/misc"
+)
+
+type Source interface {
+	AsSourceString() string
+}
+
+func parseSource(s []byte) Source {
+	nick, userhost, found := bytes.Cut(s, []byte{'!'})
+	if !found {
+		return Server{name: misc.BytesToString(s)}
+	}
+
+	user, host, found := bytes.Cut(userhost, []byte{'@'})
+	if !found {
+		return Server{name: misc.BytesToString(s)}
+	}
+
+	return Client{
+		Nick: misc.BytesToString(nick),
+		User: misc.BytesToString(user),
+		Host: misc.BytesToString(host),
+	}
+}
+
+type Server struct {
+	name string
+}
+
+func (s Server) AsSourceString() string {
+	return s.name
+}
+
+type Client struct {
+	Nick string
+	User string
+	Host string
+}
+
+func (c Client) AsSourceString() string {
+	return c.Nick + "!" + c.User + "@" + c.Host
+}
diff --git a/go.mod b/go.mod
index d9cda01..b9eeef9 100644
--- a/go.mod
+++ b/go.mod
@@ -18,7 +18,6 @@ require (
 	github.com/tdewolff/minify/v2 v2.22.4
 	github.com/yuin/goldmark v1.7.8
 	go.lindenii.runxiyu.org/lindenii-common v0.0.0-20250321131425-dda3538a9cd4
-	go.lindenii.runxiyu.org/lindenii-irc v0.0.0-20250322030600-1e47f911f1fa
 	golang.org/x/crypto v0.36.0
 )
 
diff --git a/go.sum b/go.sum
index b3c4db7..6b1b555 100644
--- a/go.sum
+++ b/go.sum
@@ -123,8 +123,6 @@ github.com/yuin/goldmark v1.7.8 h1:iERMLn0/QJeHFhxSt3p6PeN9mGnvIKSpG9YYorDMnic=
 github.com/yuin/goldmark v1.7.8/go.mod h1:uzxRWxtg69N339t3louHJ7+O03ezfj6PlliRlaOzY1E=
 go.lindenii.runxiyu.org/lindenii-common v0.0.0-20250321131425-dda3538a9cd4 h1:xX6s8+Yo5fRHzVswlJvKQjjN6lZCG7lAh33dTXBqsYE=
 go.lindenii.runxiyu.org/lindenii-common v0.0.0-20250321131425-dda3538a9cd4/go.mod h1:bOxuuGXA3UpbLb1lKohr2j2MVcGGLcqfAprGx9VCkMA=
-go.lindenii.runxiyu.org/lindenii-irc v0.0.0-20250322030600-1e47f911f1fa h1:LU3ZN/9xVUOEHyUCa5d+lvrL2sqhy/PR2iM2DuAQDqs=
-go.lindenii.runxiyu.org/lindenii-irc v0.0.0-20250322030600-1e47f911f1fa/go.mod h1:fE6Ks8GK7PHZGAPkTWG593UmF7FmyugcRcqmey3Nvy0=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=