ret1, ret2 = nil, nil --return for parallel functions

textStart = 11

function drawHeader()

    -- Big B
    term.setBackgroundColor(colors.orange)
    term.setCursorPos(0, 1)            term.write("2")
    term.setCursorPos(0, 1)            term.write("1")
    term.setCursorPos(4, 8)            term.write("   ")

    -- Big M
    term.setBackgroundColor(colors.red)
    term.setCursorPos(4, 4)            term.write("   ")
    term.setCursorPos(8, 4)            term.write("   ")
    term.setCursorPos(4, 5)            term.write(" ")
    term.setCursorPos(7, 5)            term.write(" ")
    term.setCursorPos(10, 5)        term.write(" ")
    term.setCursorPos(10, 6)        term.write(" ")

    -- Text
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.orange)
    term.setCursorPos(13, 5)        term.write("Global Alliance Bank.")
    term.setTextColor(colors.white)
    term.setBackgroundColor(colors.black)
end

function drawButtons()
    term.setBackgroundColor(colors.lightGray)
    term.setCursorPos(3, textStart)        term.write("  ")
    term.setCursorPos(3, textStart + 2)    term.write("  ")
    term.setCursorPos(3, textStart + 4)    term.write("  ")
    term.setCursorPos(3, textStart + 6)    term.write("  ")

    term.setCursorPos(48, textStart)    term.write("  ")
    term.setCursorPos(48, textStart + 2)    term.write("  ")
    term.setCursorPos(48, textStart + 4)    term.write("  ")
    term.setCursorPos(48, textStart + 6)    term.write("  ")

    term.setBackgroundColor(colors.black)
end

function drawButton(button, text)
    local x, y
    if button == 1 then    x = 6        y = textStart        end
    if button == 2 then    x = 6        y = textStart + 2    end
    if button == 3 then    x = 6        y = textStart + 4    end
    if button == 4 then    x = 6        y = textStart + 6    end

    if button == 5 then    x = 47 - #text    y = textStart        end
    if button == 6 then    x = 47 - #text    y = textStart + 2    end
    if button == 7 then    x = 47 - #text    y = textStart + 4    end
    if button == 8 then    x = 47 - #text    y = textStart + 6    end

    term.setCursorPos(x, y)
    term.write(text)
end

function drawError(error)
    -- Outer Triangle
    term.setBackgroundColor(colors.red)
    term.setCursorPos(12, textStart)            term.write(" ")
    term.setCursorPos(11, textStart + 1)        term.write(" ")
    term.setCursorPos(10, textStart + 2)        term.write(" ")
    term.setCursorPos(9, textStart + 3)            term.write(" ")
    term.setCursorPos(8, textStart + 4)            term.write(" ")
    term.setCursorPos(7, textStart + 5)            term.write(" ")
    term.setCursorPos(6, textStart + 6)            term.write("             ")

    term.setCursorPos(13, textStart + 1)        term.write(" ")
    term.setCursorPos(14, textStart + 2)        term.write(" ")
    term.setCursorPos(15, textStart + 3)        term.write(" ")
    term.setCursorPos(16, textStart + 4)        term.write(" ")
    term.setCursorPos(17, textStart + 5)        term.write(" ")

    -- Inner Triangle
    term.setBackgroundColor(colors.white)
    term.setCursorPos(12, textStart + 1)        term.write(" ")
    term.setCursorPos(11, textStart + 2)        term.write("   ")
    term.setCursorPos(10, textStart + 3)        term.write("     ")
    term.setCursorPos(9, textStart + 4)            term.write("       ")
    term.setCursorPos(8, textStart + 5)            term.write("         ")

    -- !
    term.setBackgroundColor(colors.black)
    term.setCursorPos(12, textStart + 2)        term.write(" ")
    term.setCursorPos(12, textStart + 3)        term.write(" ")
    term.setCursorPos(12, textStart + 5)        term.write(" ")

    -- Text
    term.setBackgroundColor(colors.black)
    term.setCursorPos(20, textStart)            term.write(error)

    term.setBackgroundColor(colors.black)
end

function center(y, sText)
    local w, h = term.getSize()
    x = math.max(math.floor((w - #sText) / 2), 0)
    term.setCursorPos(x, y)
    print(sText)
    return x
end

function waitForMouse()
    while true do
        local event, p1, p2, p3 = os.pullEvent("mouse_click")
        if p1 == 1 then
            ret1, ret2 = p2, p3
            return p2, p3
        end
    end
end

function waitForButton()
    while true do
        local mx, my = waitForMouse()
        if my == textStart and mx >= 3 and mx <= 4 then            ret1 = 1    return 1    end
        if my == textStart + 2 and mx >= 3 and mx <= 4 then        ret1 = 2    return 2    end
        if my == textStart + 4 and mx >= 3 and mx <= 4 then        ret1 = 3    return 3    end
        if my == textStart + 6 and mx >= 3 and mx <= 4 then        ret1 = 4    return 4    end

        if my == textStart and mx >= 48 and mx <= 49 then        ret1 = 5    return 5    end
        if my == textStart + 2 and mx >= 48 and mx <= 49 then        ret1 = 6    return 6    end
        if my == textStart + 4 and mx >= 48 and mx <= 49 then        ret1 = 7    return 7    end
        if my == textStart + 6 and mx >= 48 and mx <= 49 then        ret1 = 8    return 8    end
    end
end

function waitForChar()
    while true do
        local event, p1 = os.pullEvent("char")
        ret1 = p1
        return p1
    end
end

function waitForKey()
    while true do
        local event, p1 = os.pullEvent("key")
        ret1 = p1
        return p1
    end
end

function waitForEnter()
    while true do
        local p1 = waitForKey()
        if p1 == 28 then
            return
        end
    end
end

function waitForDisk()
    while true do
        local event, p1 = os.pullEvent("disk")
        return
    end
end