napcat: NapCatQQ (OneBot 11) Go SDK, initial release

cqcode.go

@@ -0,0 +1,98 @@
+package napcat
+
+import (
+	"sort"
+	"strings"
+)
+
+// ParseCQ 将 CQ 码字符串解析为消息段数组。
+// 文本与 [CQ:type,k=v] 混排时会还原为对应的段序列。
+func ParseCQ(s string) []Segment {
+	var out []Segment
+	var text strings.Builder
+	flush := func() {
+		if text.Len() > 0 {
+			out = append(out, Text(unescapeText(text.String())))
+			text.Reset()
+		}
+	}
+	for i := 0; i < len(s); {
+		if strings.HasPrefix(s[i:], "[CQ:") {
+			end := strings.IndexByte(s[i:], ']')
+			if end < 0 {
+				text.WriteString(s[i:])
+				break
+			}
+			end += i
+			flush()
+			out = append(out, parseCQBody(s[i+4:end]))
+			i = end + 1
+			continue
+		}
+		text.WriteByte(s[i])
+		i++
+	}
+	flush()
+	return out
+}
+
+func parseCQBody(body string) Segment {
+	parts := strings.Split(body, ",")
+	seg := Segment{Type: strings.ToLower(strings.TrimSpace(parts[0])), Data: map[string]any{}}
+	for _, p := range parts[1:] {
+		k, v, ok := strings.Cut(p, "=")
+		if !ok {
+			continue
+		}
+		seg.Data[strings.TrimSpace(k)] = unescapeParam(v)
+	}
+	return seg
+}
+
+// EncodeCQ 将消息段数组编码为 CQ 码字符串。
+func EncodeCQ(segs []Segment) string {
+	var b strings.Builder
+	for _, s := range segs {
+		if s.Type == "text" {
+			b.WriteString(escapeText(strOf(s.Data["text"])))
+			continue
+		}
+		b.WriteString("[CQ:" + s.Type)
+		keys := make([]string, 0, len(s.Data))
+		for k := range s.Data {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+		for _, k := range keys {
+			b.WriteString(",")
+			b.WriteString(k)
+			b.WriteString("=")
+			b.WriteString(escapeParam(strOf(s.Data[k])))
+		}
+		b.WriteString("]")
+	}
+	return b.String()
+}
+
+// String 将单个消息段编码为 CQ 码。
+func (s Segment) String() string { return EncodeCQ([]Segment{s}) }
+
+func escapeText(s string) string {
+	r := strings.NewReplacer("&", "&#38;", "[", "&#91;", "]", "&#93;")
+	return r.Replace(s)
+}
+
+func escapeParam(s string) string {
+	r := strings.NewReplacer("&", "&#38;", "[", "&#91;", "]", "&#93;", ",", "&#44;")
+	return r.Replace(s)
+}
+
+func unescapeText(s string) string {
+	r := strings.NewReplacer("&#91;", "[", "&#93;", "]", "&#38;", "&")
+	return r.Replace(s)
+}
+
+func unescapeParam(s string) string {
+	r := strings.NewReplacer("&#44;", ",", "&#91;", "[", "&#93;", "]", "&#38;", "&")
+	return r.Replace(s)
+}