IMonitorAPI

imonitor = {}

local monitor

local function round(num)
    return math.floor(num + 0.5)
end

function exact_send(x, y, msg)
    monitor.setCursorPos(x,y)
    monitor.write(msg)
end

local function getCX(msg)
    local width, height = monitor.getSize()
    local length = string.len(msg)
    local cx = round(((width+1)-length)/2)
    return cx
end

function f_send(pos, y, msg)
    local length = string.len(msg)
    local width, height = monitor.getSize()
    if pos == "RIGHT" then
        exact_send(width-length, y, msg)
    elseif pos == "CENTER" then
        local cx = round(((width+1)-length)/2)
        exact_send(cx, y, msg)
    elseif pos == "LEFT" then
        exact_send(1, y, msg)
    else
        error("Invalid argument: "..pos)
    end
end

function c_send(y, msg)
    f_send("CENTER", y, msg)
end

function r_send(y, msg)
    f_send("RIGHT", y, msg)
end

function l_send(y, msg)
    f_send("LEFT", y, msg)
end

--x can be a # or a position ('LEFT', 'RIGHT', 'CENTER')
function send(x, y, msg)
    if type(x) == "string" then
        f_send(x, y, msg)
        return
    end
    exact_send(x, y, msg)
end

function draw_color_bar(x, y, color, percent)
    send(x,y,"[")
    local limit = round(percent/10)
    local oX = getCX(limit)
    for i = 0, limit, 1 do
        monitor.setCursorPos(getX(oX+i), y)
        monitor.blit(" ", color, color)
    end
    for i = limit, 9, 1 do
        send(getX(oX+i), y, " ")
    end
    send(getX(oX+9), y, "]")
end

function draw_bar(x, y, percent)
    local bar = "["
    local limit = round(percent/10)
    for i=0, limit, 1 do
        bar = bar.."="
    end
    for i=limit, 9, 1 do
        bar = bar.." "
    end
    bar = bar.."]"

    send(x, y, bar)
end

function setMonitor(some_monitor)
    monitor = some_monitor
end

return imonitor