fix(greenhouse): set scroll boundary properly, fix text cutoff

this means you can no longer scroll away the text until it isnt seen
this commit also fixes text cutoff when using lunacolors
(like in the doc command)

nature/greenhouse/init.lua

@@ -44,6 +44,21 @@ function Greenhouse:updateCurrentPage(text)
 	page:setText(text)
 end
 
+local function sub(str, limit)
+	local overhead = 0
+	local function addOverhead(s)
+		overhead = overhead + string.len(s)
+	end
+
+	local s = str:gsub('\x1b%[%d+;%d+;%d+;%d+;%d+%w', addOverhead)
+     :gsub('\x1b%[%d+;%d+;%d+;%d+%w', addOverhead)
+     :gsub('\x1b%[%d+;%d+;%d+%w',addOverhead)
+     :gsub('\x1b%[%d+;%d+%w', addOverhead)
+     :gsub('\x1b%[%d+%w', addOverhead)
+
+	return s:sub(0, limit + overhead)
+end
+
 function Greenhouse:draw()
 	local workingPage = self.pages[self.curPage]
 	local offset = self.offset
@@ -56,10 +71,9 @@ function Greenhouse:draw()
 	self.sink:write(ansikit.getCSI(self.start .. ';1', 'H'))
 	self.sink:write(ansikit.getCSI(2, 'J'))
 
-	-- the -2 negate is for the command and status line
-	for i = offset, offset + (self.region.height - self.start) do
+	for i = offset, offset + (self.region.height - 1) do
 		if i > #lines then break end
-		self.sink:writeln('\r' .. lines[i]:gsub('\t', '        '):sub(0, self.region.width - 2))
+		self.sink:writeln('\r' .. sub(lines[i]:gsub('\t', '        '), self.region.width - 2))
 	end
 	self.sink:write '\r'
 	self:render()
@@ -82,7 +96,7 @@ function Greenhouse:scroll(direction)
 
 	local oldOffset = self.offset
 	if direction == 'down' then
-		self.offset = math.min(self.offset + 1, #lines)
+		self.offset = math.min(self.offset + 1, math.max(1, #lines - self.region.height + 1))
 	elseif direction == 'up' then
 		self.offset = math.max(self.offset - 1, 1)
 	end