--[[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
    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
                os.shutdown()
            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