ComputerCraft program to display useful tips on a connected monitor

wisdom.lua

------------------------------------------------
-- Wisdom
------------------------------------------------

local WISDOM = {
	"If you do your best, whatever happens will be for the best.",
	"Things that go away by themselves can come back by themselves.",
	"Plaid shirts and striped pants rarely\nmake a positive fashion statement.",
	"You should never dive into murky waters.",
	"It's never too late to learn to play the piano.",
	"You can hurt yourself if you run with scissors.",
	"You should never look directly at the sun.",
	"This is the last tip.",
}

local WISDOM_COLORS = {
	0xFF0000,
	0xFFBF00,
	0xFFFF00,
	0xBFFF00,
	0x00FF00,
	0x00FFBF,
	0x00FFFF,
	0x00BFFF,
}

local DAY_START = 06.00 -- 6:00 AM
local NIGHT_START = 19.50 -- 7:30 PM

------------------------------------------------

local function printCentered(text, yOffset)
	local width, height = term.getSize()
	local row = math.floor(height / 2) + yOffset + 1
	for line in string.gmatch(text, "([^\n]+)") do
		local column = math.ceil((width - string.len(line)) / 2) + 1
		term.setCursorPos(column, row)
		term.write(line)
		row = row + 1
	end
end

local function fadeColor(index, startColor, endColor)
	local function lerp(a, b, c)
		return a + (b - a) * c
	end

	local cR, cG, cB = colors.unpackRGB(startColor)
	local tR, tG, tB = colors.unpackRGB(endColor)
	for i = 0, 63 do
		local c = i / 63
		term.setPaletteColor(index, lerp(cR, tR, c), lerp(cG, tG, c), lerp(cB, tB, c))
		sleep()
	end
end

local function dayCycle()
	local wisdom = WISDOM[os.day() % #WISDOM + 1]
	local wisdomColor = WISDOM_COLORS[os.day() % #WISDOM_COLORS + 1]

	term.clear()

	term.setTextColor(0x1)
	printCentered("Tip of the Day:", -2)
	term.setTextColor(0x2)
	printCentered(wisdom, 1)

	fadeColor(0x1, 0x0, wisdomColor)
	fadeColor(0x2, 0x0, wisdomColor)

	os.setAlarm(NIGHT_START)
	os.pullEvent("alarm")

	fadeColor(0x1, wisdomColor, 0x0)
	fadeColor(0x2, wisdomColor, 0x0)
end

local function nightCycle()
	local width, height = term.getSize()

	term.clear()
	term.setCursorPos(1, 1)

	-- Credit: RamiLego, dan200
	for x = 1, width do
		for y = 1, height do
			local starType = math.random(1, 30)
			if starType == 14 then
				term.setCursorPos(x, y)
				term.setTextColor(0x100)
				term.write(".")
			elseif starType == 10 then
				term.setCursorPos(x, y)
				term.setTextColor(0x100)
				term.write("*")
			elseif starType == 16 then
				term.setCursorPos(x, y)
				term.setTextColor(0x80)
				term.write(".")
			elseif starType == 3 then
				term.setCursorPos(x, y)
				term.setTextColor(0x80)
				term.write("*")
			end
		end
	end

	fadeColor(0x80, 0x0, 0x4C4C4C)
	fadeColor(0x100, 0x0, 0x999999)

	os.setAlarm(DAY_START)
	os.pullEvent("alarm")

	fadeColor(0x100, 0x999999, 0x0)
	fadeColor(0x80, 0x4C4C4C, 0x0)
end

term.clear()
term.setCursorBlink(false)

for p = 0, 15 do
	term.setPaletteColor(math.pow(2, p), 0x0)
end

while true do
	if os.time() >= DAY_START and os.time() < NIGHT_START then
		dayCycle()
	else
		nightCycle()
	end
end