1 files changed, 125 insertions, 0 deletions
diff --git a/msg.go b/msg.go
new file mode 100644
index 0000000..ff4b3a4
--- /dev/null
+++ b/msg.go
@@ -0,0 +1,125 @@
+package main
+
+import (
+	"strings"
+)
+
+type Msg struct {
+	RawMessage string
+	RawSource  string
+	Command    string
+	Tags       map[string]string
+	Params     []string
+}
+
+// Partially adapted from https://github.com/ergochat/irc-go.git
+func parseIRCMsg(line string) (msg Msg, err error) {
+	msg = Msg{
+		RawMessage: line,
+	}
+
+	line = strings.TrimSuffix(line, "\n")
+	line = strings.TrimSuffix(line, "\r")
+
+	if len(line) == 0 {
+		err = ErrEmptyMessage
+		return
+	}
+
+	for _, v := range line {
+		if v == '\x00' || v == '\r' || v == '\n' {
+			err = ErrIllegalByte
+			return
+		}
+	}
+
+	// IRCv3 tags
+	if line[0] == '@' {
+		tagEnd := strings.IndexByte(line, ' ')
+		if tagEnd == -1 {
+			err = ErrEmptyMessage
+			return
+		}
+		tagsString := line[1:tagEnd]
+		if 0 < MaxlenTagData && MaxlenTagData < len(tagsString) {
+			err = ErrTagsTooLong
+			return
+		}
+		msg.Tags, err = parseTags(tagsString)
+		if err != nil {
+			return
+		}
+		// Skip over the tags and the separating space
+		line = line[tagEnd+1:]
+	}
+
+	if len(line) > MaxlenBody {
+		err = ErrBodyTooLong
+		line = line[:MaxlenBody]
+	}
+
+	line = trimInitialSpaces(line)
+
+	// Source
+	if 0 < len(line) && line[0] == ':' {
+		sourceEnd := strings.IndexByte(line, ' ')
+		if sourceEnd == -1 {
+			err = ErrEmptyMessage
+			return
+		}
+		msg.RawSource = line[1:sourceEnd]
+		// Skip over the source and the separating space
+		line = line[sourceEnd+1:]
+	}
+
+	// Command
+	commandEnd := strings.IndexByte(line, ' ')
+	paramStart := commandEnd + 1
+	if commandEnd == -1 {
+		commandEnd = len(line)
+		paramStart = len(line)
+	}
+	baseCommand := line[:commandEnd]
+	if len(baseCommand) == 0 {
+		err = ErrEmptyMessage
+		return
+	}
+	// TODO: Actually must be either letters or a 3-digit numeric
+	if !isASCII(baseCommand) {
+		err = ErrIllegalByte
+		return
+	}
+	msg.Command = strings.ToUpper(baseCommand)
+	line = line[paramStart:]
+
+	// Other arguments
+	for {
+		line = trimInitialSpaces(line)
+		if len(line) == 0 {
+			break
+		}
+		// Trailing
+		if line[0] == ':' {
+			msg.Params = append(msg.Params, line[1:])
+			break
+		}
+		paramEnd := strings.IndexByte(line, ' ')
+		if paramEnd == -1 {
+			msg.Params = append(msg.Params, line)
+			break
+		}
+		msg.Params = append(msg.Params, line[:paramEnd])
+		line = line[paramEnd+1:]
+	}
+
+	return
+}
+
+func isASCII(str string) bool {
+	for i := 0; i < len(str); i++ {
+		if str[i] > 127 {
+			return false
+		}
+	}
+	return true
+}