1 files changed, 327 insertions, 0 deletions
diff --git a/irc/tokens.go b/irc/tokens.go
new file mode 100644
index 0000000..976207d
--- /dev/null
+++ b/irc/tokens.go
@@ -0,0 +1,327 @@
+package irc
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+)
+
+func word(s string) (w, rest string) {
+	split := strings.SplitN(s, " ", 2)
+
+	if len(split) < 2 {
+		w = split[0]
+		rest = ""
+	} else {
+		w = split[0]
+		rest = split[1]
+	}
+
+	return
+}
+
+func tagEscape(c rune) (escape rune) {
+	switch c {
+	case ':':
+		escape = ';'
+	case 's':
+		escape = ' '
+	case 'r':
+		escape = '\r'
+	case 'n':
+		escape = '\n'
+	default:
+		escape = c
+	}
+
+	return
+}
+
+func unescapeTagValue(escaped string) (unescaped string) {
+	var builder strings.Builder
+	builder.Grow(len(escaped))
+	escape := false
+
+	for _, c := range escaped {
+		if c == '\\' && !escape {
+			escape = true
+		} else {
+			var cpp rune
+
+			if escape {
+				cpp = tagEscape(c)
+			} else {
+				cpp = c
+			}
+
+			builder.WriteRune(cpp)
+			escape = false
+		}
+	}
+
+	unescaped = builder.String()
+	return
+}
+
+func parseTags(s string) (tags map[string]string) {
+	s = s[1:]
+	tags = map[string]string{}
+
+	for _, item := range strings.Split(s, ";") {
+		if item == "" || item == "=" || item == "+" || item == "+=" {
+			continue
+		}
+
+		kv := strings.SplitN(item, "=", 2)
+		if len(kv) < 2 {
+			tags[kv[0]] = ""
+		} else {
+			tags[kv[0]] = unescapeTagValue(kv[1])
+		}
+	}
+
+	return
+}
+
+var (
+	errEmptyMessage      = errors.New("empty message")
+	errIncompleteMessage = errors.New("message is incomplete")
+)
+
+var (
+	errNoPrefix        = errors.New("missing prefix")
+	errNotEnoughParams = errors.New("not enough params")
+	errUnknownCommand  = errors.New("unknown command")
+)
+
+type Message struct {
+	Tags    map[string]string
+	Prefix  string
+	Command string
+	Params  []string
+}
+
+func Tokenize(line string) (msg Message, err error) {
+	line = strings.TrimLeft(line, " ")
+	if line == "" {
+		err = errEmptyMessage
+		return
+	}
+
+	if line[0] == '@' {
+		var tags string
+
+		tags, line = word(line)
+		msg.Tags = parseTags(tags)
+	}
+
+	line = strings.TrimLeft(line, " ")
+	if line == "" {
+		err = errIncompleteMessage
+		return
+	}
+
+	if line[0] == ':' {
+		var prefix string
+
+		prefix, line = word(line)
+		msg.Prefix = prefix[1:]
+	}
+
+	line = strings.TrimLeft(line, " ")
+	if line == "" {
+		err = errIncompleteMessage
+		return
+	}
+
+	msg.Command, line = word(line)
+	msg.Command = strings.ToUpper(msg.Command)
+
+	msg.Params = make([]string, 0, 15)
+	for line != "" {
+		if line[0] == ':' {
+			msg.Params = append(msg.Params, line[1:])
+			break
+		}
+
+		var param string
+		param, line = word(line)
+		msg.Params = append(msg.Params, param)
+	}
+
+	return
+}
+
+func (msg *Message) Validate() (err error) {
+	switch msg.Command {
+	case "001":
+		if len(msg.Params) < 1 {
+			err = errNotEnoughParams
+		}
+	case "005":
+		if len(msg.Params) < 3 {
+			err = errNotEnoughParams
+		}
+	case "352":
+		if len(msg.Params) < 8 {
+			err = errNotEnoughParams
+		}
+	case "372":
+		if len(msg.Params) < 2 {
+			err = errNotEnoughParams
+		}
+	case "AUTHENTICATE":
+		if len(msg.Params) < 1 {
+			err = errNotEnoughParams
+		}
+	case "900":
+		if len(msg.Params) < 3 {
+			err = errNotEnoughParams
+		}
+	case "901":
+		if len(msg.Params) < 2 {
+			err = errNotEnoughParams
+		}
+	case "CAP":
+		if len(msg.Params) < 3 {
+			err = errNotEnoughParams
+		} else if msg.Params[1] == "LS" {
+		} else if msg.Params[1] == "LIST" {
+		} else if msg.Params[1] == "ACK" {
+		} else if msg.Params[1] == "NAK" {
+		} else if msg.Params[1] == "NEW" {
+		} else if msg.Params[1] == "DEL" {
+		} else {
+			err = errUnknownCommand
+		}
+	case "JOIN":
+		if len(msg.Params) < 1 {
+			err = errNotEnoughParams
+		} else if msg.Prefix == "" {
+			err = errNoPrefix
+		}
+	case "353":
+		if len(msg.Params) < 4 {
+			err = errNotEnoughParams
+		}
+	case "332":
+		if len(msg.Params) < 3 {
+			err = errNotEnoughParams
+		}
+	case "TOPIC":
+		if len(msg.Params) < 2 {
+			err = errNotEnoughParams
+		}
+	case "PING":
+		if len(msg.Params) < 1 {
+			err = errNotEnoughParams
+		}
+	case "PONG":
+		if len(msg.Params) < 1 {
+			err = errNotEnoughParams
+		}
+	default:
+	}
+	return
+}
+
+func (msg *Message) Time() (t time.Time, ok bool) {
+	var tag string
+	var year, month, day, hour, minute, second, millis int
+
+	tag, ok = msg.Tags["time"]
+	if !ok {
+		return
+	}
+
+	tag = strings.TrimSuffix(tag, "Z")
+
+	_, err := fmt.Sscanf(tag, "%4d-%2d-%2dT%2d:%2d:%2d.%3d", &year, &month, &day, &hour, &minute, &second, &millis)
+	if err != nil || month < 1 || 12 < month {
+		ok = false
+		return
+	}
+
+	t = time.Date(year, time.Month(month), day, hour, minute, second, millis*1000000, time.Local)
+
+	return
+}
+
+func FullMask(s string) (nick, user, host string) {
+	if s == "" {
+		return
+	}
+
+	spl0 := strings.Split(s, "@")
+	if 1 < len(spl0) {
+		host = spl0[1]
+	}
+
+	spl1 := strings.Split(spl0[0], "!")
+	if 1 < len(spl1) {
+		user = spl1[1]
+	}
+
+	nick = spl1[0]
+
+	return
+}
+
+type Cap struct {
+	Name   string
+	Value  string
+	Enable bool
+}
+
+func TokenizeCaps(caps string) (diff []Cap) {
+	for _, c := range strings.Split(caps, " ") {
+		if c == "" || c == "-" || c == "=" || c == "-=" {
+			continue
+		}
+
+		var item Cap
+
+		if strings.HasPrefix(c, "-") {
+			item.Enable = false
+			c = c[1:]
+		} else {
+			item.Enable = true
+		}
+
+		kv := strings.SplitN(c, "=", 2)
+		item.Name = strings.ToLower(kv[0])
+		if len(kv) > 1 {
+			item.Value = kv[1]
+		}
+
+		diff = append(diff, item)
+	}
+
+	return
+}
+
+type Name struct {
+	PowerLevel string
+	Nick       string
+	User       string
+	Host       string
+}
+
+func TokenizeNames(trailing string, prefixes string) (names []Name) {
+	for _, name := range strings.Split(trailing, " ") {
+		if name == "" {
+			continue
+		}
+
+		var item Name
+
+		mask := strings.TrimLeft(name, prefixes)
+		item.Nick, item.User, item.Host = FullMask(mask)
+		item.PowerLevel = name[:len(name)-len(mask)]
+
+		names = append(names, item)
+	}
+
+	return
+}