From 65bf58731fd347f7413feb0c8b01ed554c55f802 Mon Sep 17 00:00:00 2001
From: Laura Hausmann <laura@hausmann.dev>
Date: Sun, 22 Jan 2023 23:26:43 +0100
Subject: [PATCH] Remove while loop in GetViewIntoMessageBuffer, closes #12

---
 tgcli/Util.cs | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/tgcli/Util.cs b/tgcli/Util.cs
index 861c90c..1f9c14f 100644
--- a/tgcli/Util.cs
+++ b/tgcli/Util.cs
@@ -388,20 +388,14 @@ namespace tgcli {
 			if (absoluteCursorPosition < bufferWidth - wraparoundOffsetPre - 1)
 				return (TruncateString(message, bufferWidth, $"{Ansi.Inverse}>{Ansi.InverseOff}"), absoluteCursorPosition);
 
-			// now we can be sure the message needs at least one wrap
-
-			// first wrap
-			// get rid of the content shown on the zeroth wrap, which is buf width minus wraparoundPreW (respects > character on screen edge)
-			var finalMessage   = message[(bufferWidth - wraparoundOffsetPreW - wraparoundOffsetPost)..];
 			var finalCursorPos = absoluteCursorPosition - bufferWidth + wraparoundOffsetPreW + wraparoundOffsetPostW;
+			var wraparounds    = (finalCursorPos - wraparoundOffsetPostW) / (bufferWidth - wraparoundOffsetPreW - wraparoundOffsetPostW);
+			finalCursorPos += wraparoundOffsetPostW * wraparounds;
+			finalCursorPos %= bufferWidth - wraparoundOffsetPreW;
 
-			// successive wraps
-			// repeat above steps (but respective of the new < character) until the string fits into the buffer
-			// it fits into the buffer when cursorPos >= bufferwidth minus wraparound (this time respecting > character absent on first wrap)
-			while (finalCursorPos >= bufferWidth - wraparoundOffsetPreW) {
-				finalMessage   = finalMessage[(bufferWidth - wraparoundOffsetPreW - wraparoundOffsetPostW)..];
-				finalCursorPos = finalCursorPos - bufferWidth + wraparoundOffsetPreW + wraparoundOffsetPostW;
-			}
+			var messageOffset = (bufferWidth - wraparoundOffsetPreW - wraparoundOffsetPostW) * wraparounds;
+			var finalMessage  = message[(bufferWidth - wraparoundOffsetPreW - wraparoundOffsetPost)..];
+			finalMessage = finalMessage[messageOffset..];
 
 			finalMessage = TruncateString(finalMessage, bufferWidth - 1, $"{Ansi.Inverse}>{Ansi.InverseOff}");