--[[Smart Calculator by Cranium]]
--

local tX, tY = term.getSize()
local calc = {}

--equation states
calc.mode = false
calc.inverse = false
calc.hyp = false
calc.sqrt = false
calc.exp = false
calc.asin = false
calc.sin = false
calc.sinh = false
calc.atan = false
calc.tan = false
calc.tanh = false
calc.acos = false
calc.cos = false
calc.cosh = false
calc.log = false
calc.pos = false

-- characters
local charList = {
	["0"] = {
		".-.",
		"| |",
		"'-'"
	},
	["1"] = {
		" . ",
		"'| ",
		"---"
	},
	["2"] = {
		".-.",
		".-'",
		"'- "
	},
	["3"] = {
		" -.",
		" -|",
		" -'"
	},
	["4"] = {
		". .",
		"'-|",
		"  '"
	},
	["5"] = {
		".- ",
		"'-.",
		" -'"
	},
	["6"] = {
		".-.",
		"|-.",
		"'-'"
	},
	["7"] = {
		".-.",
		"  |",
		"  '"
	},
	["8"] = {
		".-.",
		"|-|",
		"'-'"
	},
	["9"] = {
		".-.",
		"'-|",
		" -'"
	},
	["."] = {
		"   ",
		"   ",
		" . "
	},
	["-"] = {
		"   ",
		" --",
		"   "
	},
}
-- lay out the button labels
local labels = {
	' + ', ' 1 ', ' 2 ', ' 3 ', '<--', 'sin', 'x^y', 'DEG', 'OFF',
	' - ', ' 4 ', ' 5 ', ' 6 ', 'CLR', 'cos', 'srt', 'RAD', '   ',
	' x ', ' 7 ', ' 8 ', ' 9 ', '   ', 'tan', 'Pi ', 'inv', '   ',
	' / ', ' 0 ', '-/+', ' . ', ' = ', 'log', 'exp', 'hyp', '   '
}


-- generate the objects
local function objGen()
	local _objects = {}
	local width = 9
	for i = 1, #labels do
		table.insert(_objects, {
			x = (((i - 1) % width + 1) * 5) - 1,
			y = (math.ceil(i / width) * 3) + 4,
			label = labels[i],
			-- make operators different colors
			color =
				i == 1 and colors.blue or
				i == 5 and colors.red or
				i == 6 and colors.yellow or
				i == 7 and colors.orange or
				i == 8 and colors.white or
				i == 9 and colors.red or
				i == 10 and colors.blue or
				i == 14 and colors.red or
				i == 15 and colors.yellow or
				i == 16 and colors.orange or
				i == 17 and colors.white or
				i == 18 and colors.white or
				i == 19 and colors.blue or
				i == 24 and colors.yellow or
				i == 25 and colors.orange or
				i == 26 and colors.white or
				i == 27 and colors.white or
				i == 28 and colors.blue or
				i == 30 and colors.red or
				i == 32 and colors.white or
				i == 33 and colors.yellow or
				i == 34 and colors.orange or
				i == 35 and colors.white or
				i == 36 and colors.white or
				colors.lightGray,
			-- controls the highlight colors for operators
			back =
				i == 6 and
				calc.sin == true and colors.red or
				calc.asin == true and colors.red or
				calc.sinh == true and colors.red or
				i == 8 and calc.mode == "deg" and colors.blue or
				i == 15 and
				calc.cos == true and colors.red or
				calc.acos == true and colors.red or
				calc.cosh == true and colors.red or
				i == 16 and calc.sqrt == true and colors.lightBlue or
				i == 17 and calc.mode == "rad" and colors.blue or
				i == 24 and
				calc.tan == true and colors.red or
				calc.atan == true and colors.red or
				calc.tanh == true and colors.red or
				i == 26 and calc.inverse == true and colors.blue or
				i == 30 and calc.pos == true and colors.white or
				i == 33 and calc.log == true and colors.red or
				i == 34 and calc.exp == true and colors.lightBlue or
				i == 35 and calc.hyp == true and colors.blue or
				colors.black,
		})
	end
	return _objects
end

local function draw()
	term.setBackgroundColor(colors.black)
	term.clear()
	local objects = objGen()
	for i = 1, #objects do
		local obj = objects[i]
		term.setTextColor(colors.gray)
		term.setBackgroundColor(colors.black)
		--draw the grid
		for num, line in pairs { '+---+', '|   |', '+---+' } do
			term.setCursorPos(obj.x, obj.y + num - 1)
			write(line)
		end
		--draw the button text and colors
		term.setCursorPos(obj.x + 1, obj.y + 1)
		term.setTextColor(obj.color)
		term.setBackgroundColor(obj.back)
		write(obj.label)
	end
end
--draw border and screen
local function display()
	term.setBackgroundColor(colors.black)
	term.setTextColor(colors.gray)
	term.setCursorPos(2, 1)
	write("+" .. string.rep("-", tX - 4) .. "+")
	for i = 2, tY - 1 do
		term.setCursorPos(2, i)
		write("|")
		term.setCursorPos(tX - 1, i)
		write("|")
	end
	term.setCursorPos(2, tY)
	write("+" .. string.rep("-", tX - 4) .. "+")
	term.setBackgroundColor(colors.lightGray)
	for i = 2, 6 do
		term.setCursorPos(4, i)
		write(string.rep(" ", tX - 6))
	end
end
--run the equation passed by the user.
local function calculate(eq)
	if table.concat(eq) == "()" then
		eq = { "0" }
	elseif table.concat(eq) == "(.)" then
		eq = { "0" }
	end
	local sExpr = table.concat(eq)
	local fnMath, sErr = loadstring("return " .. sExpr)
	if not fnMath then
		return "ERROR! Check syntax!"
	end
	--setfenv(fnMath, math)
	local bSucc, vRes = pcall(fnMath)
	if not bSucc then
		return "ERROR! Check syntax!"
	else
		return vRes
	end
end

-- function loop
local equation = { "(", ")" }
local result = "0"
while true do
	local rLen = 0
	draw()
	display()
	term.setBackgroundColor(colors.lightGray)
	term.setTextColor(colors.white)
	term.setCursorPos(4, 2)
	--write the equation
	write(table.concat(equation))
	--write the result
	if tonumber(result) ~= inf then
		if string.len(result) >= 15 then
			term.setCursorPos(5, 4)
			term.setTextColor(colors.black)
			write("= ")
			for num in string.gmatch(result, ".") do
				rLen = rLen + 1
				local pX, pY = term.getCursorPos()
				if pX >= 4 and pX <= 48 then
					term.setCursorPos(rLen + 5, 4)
					write(num)
				else
					term.setCursorPos(rLen + 5 - 48, 5)
					write(num)
				end
			end
		else
			for num in string.gmatch(result, ".") do
				rLen = rLen + 1
				for i = 1, #charList[num] do
					term.setTextColor(colors.black)
					term.setCursorPos((rLen * 3) + 1, i + 3)
					write(charList[num][i])
				end
			end
		end
	elseif result == nil then
		term.setCursorPos(5, 4)
		term.setTextColor(colors.black)
		write("= ERROR")
	else
		term.setCursorPos(5, 4)
		term.setTextColor(colors.black)
		write("= INFINITY")
	end
	local events = { os.pullEvent() }
	--mouse click filter
	if events[1] == "mouse_click" and events[2] == 1 then
		if events[3] >= 44 and events[3] <= 48 then
			if events[4] >= 7 and events[4] <= 9 then
				term.setBackgroundColor(colors.black)
				term.clear()
				term.setCursorPos(1, 1)
				os.reboot()
			end
		elseif events[3] >= 39 and events[3] <= 43 then
			if events[4] >= 7 and events[4] <= 9 then
				if calc.mode == false then
					table.remove(equation, 1)
					calc.mode = "deg"
					table.insert(equation, 1, "math.deg(")
				elseif calc.mode == "deg" then
					table.remove(equation, 1)
					calc.mode = false
				elseif calc.mode == "rad" then
					table.remove(equation, 1)
					calc.mode = "deg"
					table.insert(equation, 1, "math.deg(")
				end
			elseif events[4] >= 10 and events[4] <= 12 then
				if calc.mode == false then
					table.remove(equation, 1)
					calc.mode = "rad"
					table.insert(equation, 1, "math.rad(")
				elseif calc.mode == "rad" then
					table.remove(equation, 1)
					calc.mode = false
				elseif calc.mode == "deg" then
					table.remove(equation, 1)
					calc.mode = "rad"
					table.insert(equation, 1, "math.rad(")
				end
			elseif events[4] >= 13 and events[4] <= 15 then
				if calc.inverse == true and calc.hyp == false then
					calc.inverse = false
				elseif calc.inverse == false and calc.hyp == true then
					calc.inverse = true
					calc.hyp = false
				elseif calc.inverse == false and calc.hyp == false then
					calc.inverse = true
				end
			elseif events[4] >= 16 and events[4] <= 18 then
				if calc.hyp == true and calc.inverse == false then
					calc.hyp = false
				elseif calc.hyp == false and calc.inverse == true then
					calc.hyp = true
					calc.inverse = false
				elseif calc.hyp == false and calc.inverse == false then
					calc.hyp = true
				end
			end
		elseif events[3] >= 34 and events[3] <= 38 then
			if events[4] >= 7 and events[4] <= 9 then
				table.insert(equation, #equation, "^")
			elseif events[4] >= 10 and events[4] <= 12 then
				if calc.sqrt == false then
					table.insert(equation, #equation, "math.sqrt(")
					calc.sqrt = true
				elseif calc.sqrt == true then
					table.insert(equation, #equation, ")")
					calc.sqrt = false
				end
			elseif events[4] >= 13 and events[4] <= 15 then
				table.insert(equation, #equation, "math.pi")
			elseif events[4] >= 16 and events[4] <= 18 then
				if calc.exp == false then
					table.insert(equation, #equation, "math.exp(")
					calc.exp = true
				elseif calc.exp == true then
					table.insert(equation, #equation, ")")
					calc.exp = false
				end
			end
		elseif events[3] >= 29 and events[3] <= 33 then
			if events[4] >= 7 and events[4] <= 9 then
				if calc.inverse == true and calc.asin == false then
					table.insert(equation, #equation, "math.asin(")
					calc.asin = true
				elseif calc.inverse == false and calc.hyp == false and calc.sin == false then
					table.insert(equation, #equation, "math.sin(")
					calc.sin = true
				elseif calc.hyp == true and calc.sinh == false then
					table.insert(equation, #equation, "math.sinh(")
					calc.sinh = true
				elseif calc.asin == true then
					table.insert(equation, #equation, ")")
					calc.asin = false
				elseif calc.sin == true then
					table.insert(equation, #equation, ")")
					calc.sin = false
				elseif calc.sinh == true then
					table.insert(equation, #equation, ")")
					calc.sinh = false
				end
			elseif events[4] >= 10 and events[4] <= 12 then
				if calc.inverse == true and calc.acos == false then
					table.insert(equation, #equation, "math.acos(")
					calc.acos = true
				elseif calc.inverse == false and calc.hyp == false and calc.cos == false then
					table.insert(equation, #equation, "math.cos(")
					calc.cos = true
				elseif calc.hyp == true and calc.cosh == false then
					table.insert(equation, #equation, "math.cosh(")
					calc.cosh = true
				elseif calc.acos == true then
					table.insert(equation, #equation, ")")
					calc.acos = false
				elseif calc.cos == true then
					table.insert(equation, #equation, ")")
					calc.cos = false
				elseif calc.cosh == true then
					table.insert(equation, #equation, ")")
					calc.cosh = false
				end
			elseif events[4] >= 13 and events[4] <= 15 then
				if calc.inverse == true and calc.atan == false then
					table.insert(equation, #equation, "math.atan(")
					calc.atan = true
				elseif calc.inverse == false and calc.hyp == false and calc.tan == false then
					table.insert(equation, #equation, "math.tan(")
					calc.tan = true
				elseif calc.hyp == true and calc.tanh == false then
					table.insert(equation, #equation, "math.tanh(")
					calc.tanh = true
				elseif calc.atan == true then
					table.insert(equation, #equation, ")")
					calc.atan = false
				elseif calc.tan == true then
					table.insert(equation, #equation, ")")
					calc.tan = false
				elseif calc.tanh == true then
					table.insert(equation, #equation, ")")
					calc.tanh = false
				end
			elseif events[4] >= 16 and events[4] <= 18 then
				if calc.log == false then
					table.insert(equation, #equation, "math.log10(")
					calc.log = true
				elseif calc.log == true then
					table.insert(equation, ")")
					calc.log = false
				end
			end
			-- backspace, clear, equals
		elseif events[3] >= 24 and events[3] <= 28 then
			if events[4] >= 7 and events[4] <= 9 then
				if table.concat(equation) ~= "()" then
					table.remove(equation, #equation - 1)
				end
			elseif events[4] >= 10 and events[4] <= 12 then
				calc.mode = false
				calc.inverse = false
				calc.hyp = false
				calc.sqrt = false
				calc.exp = false
				calc.asin = false
				calc.sin = false
				calc.sinh = false
				calc.atan = false
				calc.tan = false
				calc.tanh = false
				calc.acos = false
				calc.cos = false
				calc.cosh = false
				calc.log = false
				calc.pos = false
				equation = { "(", ")" }
				result = "0"
			elseif events[4] >= 16 and events[4] <= 18 then
				if equation[#equation - 1] == "+" or
					equation[#equation - 1] == "-" or
					equation[#equation - 1] == "*" or
					equation[#equation - 1] == "/" then
					table.insert(equation, #equation, "0")
				elseif equation[#equation - 1] == "^" then
					table.insert(equation, #equation, "1")
				end
				for i, v in pairs(calc) do
					if calc[i] == true then
						table.insert(equation, #equation, ")")
						calc[i] = false
					end
				end
				result = tostring(calculate(equation))
			end
			-- 3, 6, 9, decimal
		elseif events[3] >= 19 and events[3] <= 23 then
			if events[4] >= 7 and events[4] <= 9 then
				table.insert(equation, #equation, "3")
			elseif events[4] >= 10 and events[4] <= 12 then
				table.insert(equation, #equation, "6")
			elseif events[4] >= 13 and events[4] <= 15 then
				table.insert(equation, #equation, "9")
			elseif events[4] >= 16 and events[4] <= 18 then
				table.insert(equation, #equation, ".")
			end
			-- 2, 5, 8, positive/negative
		elseif events[3] >= 14 and events[3] <= 18 then
			if events[4] >= 7 and events[4] <= 9 then
				table.insert(equation, #equation, "2")
			elseif events[4] >= 10 and events[4] <= 12 then
				table.insert(equation, #equation, "5")
			elseif events[4] >= 13 and events[4] <= 15 then
				table.insert(equation, #equation, "8")
			elseif events[4] >= 16 and events[4] <= 18 then
				if calc.pos == false then
					table.insert(equation, #equation, "(-")
					calc.pos = true
				elseif calc.pos == true then
					table.insert(equation, #equation, ")")
					calc.pos = false
				end
			end
			-- 1, 4, 7, 0
		elseif events[3] >= 9 and events[3] <= 13 then
			if events[4] >= 7 and events[4] <= 9 then
				table.insert(equation, #equation, "1")
			elseif events[4] >= 10 and events[4] <= 12 then
				table.insert(equation, #equation, "4")
			elseif events[4] >= 13 and events[4] <= 15 then
				table.insert(equation, #equation, "7")
			elseif events[4] >= 16 and events[4] <= 18 then
				table.insert(equation, #equation, "0")
			end
			-- add, subtract, multiply, divide
		elseif events[3] >= 4 and events[3] <= 8 then
			if events[4] >= 7 and events[4] <= 9 then
				table.insert(equation, #equation, "+")
			elseif events[4] >= 10 and events[4] <= 12 then
				table.insert(equation, #equation, "-")
			elseif events[4] >= 13 and events[4] <= 15 then
				table.insert(equation, #equation, "*")
			elseif events[4] >= 16 and events[4] <= 18 then
				table.insert(equation, #equation, "/")
			end
		end
		-- filter for keyboard presses
	elseif events[1] == "key" then
		if events[2] == 79 then
			table.insert(equation, #equation, "1")
		elseif events[2] == 80 then
			table.insert(equation, #equation, "2")
		elseif events[2] == 81 then
			table.insert(equation, #equation, "3")
		elseif events[2] == 75 then
			table.insert(equation, #equation, "4")
		elseif events[2] == 76 then
			table.insert(equation, #equation, "5")
		elseif events[2] == 77 then
			table.insert(equation, #equation, "6")
		elseif events[2] == 71 then
			table.insert(equation, #equation, "7")
		elseif events[2] == 72 then
			table.insert(equation, #equation, "8")
		elseif events[2] == 73 then
			table.insert(equation, #equation, "9")
		elseif events[2] == 82 then
			table.insert(equation, #equation, "0")
		elseif events[2] == 83 then
			table.insert(equation, #equation, ".")
		elseif events[2] == 78 then
			table.insert(equation, #equation, "+")
		elseif events[2] == 74 then
			table.insert(equation, #equation, "-")
		elseif events[2] == 55 then
			table.insert(equation, #equation, "*")
		elseif events[2] == 181 then
			table.insert(equation, #equation, "/")
		elseif events[2] == 14 then
			if table.concat(equation) ~= "()" then
				table.remove(equation, #equation - 1)
			end
		elseif events[2] == 28 or events[2] == 156 then
			if equation[#equation - 1] == "+" or
				equation[#equation - 1] == "-" or
				equation[#equation - 1] == "*" or
				equation[#equation - 1] == "/" then
				table.insert(equation, #equation, "0")
			elseif equation[#equation - 1] == "^" then
				table.insert(equation, #equation, "1")
			end
			for i, v in pairs(calc) do
				if calc[i] == true then
					table.insert(equation, #equation, ")")
					calc[i] = false
				end
			end
			result = tostring(calculate(equation))
		end
	end
end