draft/resume-0.2 implementation, message history support

irc/utils/text.go

@@ -0,0 +1,67 @@
+// Copyright (c) 2017 Daniel Oaks <daniel@danieloaks.net>
+// released under the MIT license
+
+package utils
+
+import "bytes"
+
+// WordWrap wraps the given text into a series of lines that don't exceed lineWidth characters.
+func WordWrap(text string, lineWidth int) []string {
+	var lines []string
+	var cacheLine, cacheWord bytes.Buffer
+
+	for _, char := range text {
+		if char == '\r' {
+			continue
+		} else if char == '\n' {
+			cacheLine.Write(cacheWord.Bytes())
+			lines = append(lines, cacheLine.String())
+			cacheWord.Reset()
+			cacheLine.Reset()
+		} else if (char == ' ' || char == '-') && cacheLine.Len()+cacheWord.Len()+1 < lineWidth {
+			// natural word boundary
+			cacheLine.Write(cacheWord.Bytes())
+			cacheLine.WriteRune(char)
+			cacheWord.Reset()
+		} else if lineWidth <= cacheLine.Len()+cacheWord.Len()+1 {
+			// time to wrap to next line
+			if cacheLine.Len() < (lineWidth / 2) {
+				// this word takes up more than half a line... just split in the middle of the word
+				cacheLine.Write(cacheWord.Bytes())
+				cacheLine.WriteRune(char)
+				cacheWord.Reset()
+			} else {
+				cacheWord.WriteRune(char)
+			}
+			lines = append(lines, cacheLine.String())
+			cacheLine.Reset()
+		} else {
+			// normal character
+			cacheWord.WriteRune(char)
+		}
+	}
+	if 0 < cacheWord.Len() {
+		cacheLine.Write(cacheWord.Bytes())
+	}
+	if 0 < cacheLine.Len() {
+		lines = append(lines, cacheLine.String())
+	}
+
+	return lines
+}
+
+// SplitMessage represents a message that's been split for sending.
+type SplitMessage struct {
+	Original string
+	Wrapped  []string // if this is nil, Original didn't need wrapping and can be sent to anyone
+}
+
+func MakeSplitMessage(original string, origIs512 bool) (result SplitMessage) {
+	result.Original = original
+
+	if !origIs512 {
+		result.Wrapped = WordWrap(original, 400)
+	}
+
+	return
+}