os.pullEvent = os.pullEventRaw

local buttons = {
    { name = "Command", x = 2, y = 3, width = 15, height = 1, color = colors.gray, command = "/disk/os/home.lua" },
    { name = "Programs", x = 2, y = 5, width = 15, height = 1, color = colors.gray, command = "/disk/os/programs" },
    { name = "Power Menu", x = 2, y = 7, width = 15, height = 1, color = colors.gray, command = "showPowerMenu" }
}

local function drawButton(button)
    term.setBackgroundColor(button.color)
    term.setTextColor(colors.white)
    term.setCursorPos(button.x, button.y)
    term.clearLine()
    term.write(" " .. button.name .. " ")
end

local function drawPowerMenu()
    term.setBackgroundColor(colors.gray)
    term.setTextColor(colors.white)
    term.setCursorPos(2, 8)
    term.clearLine()
    term.write(" Shut Down ")

    term.setCursorPos(2, 9)
    term.clearLine()
    term.write(" Reboot ")

    term.setCursorPos(2, 10)
    term.clearLine()
    term.write(" Lock ")
end

local function drawHomescreen()
    term.setBackgroundColor(colors.black)
    term.clear()

    term.setCursorPos(1, 1)
    term.setBackgroundColor(colors.blue)
    term.setTextColor(colors.white)
    term.write("        Doggy OS 12.0        ")
    term.setBackgroundColor(colors.black)

    for _, button in ipairs(buttons) do
        drawButton(button)
    end
end

local function drawNavBar()
    local screenWidth, screenHeight = term.getSize()
    local navBarWidth = 20
    local navBarStart = math.floor((screenWidth - navBarWidth) / 2)

    term.setCursorPos(navBarStart + 4, screenHeight)
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.write(" lll ")

    term.setCursorPos(navBarStart + 9, screenHeight)
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.write(" () ")

    term.setCursorPos(navBarStart + 14, screenHeight)
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.write(" < ")
end

local function isClickOnButton(x, y)
    for _, button in ipairs(buttons) do
        if x >= button.x and x < button.x + button.width and y == button.y then
            return button.command
        end
    end
    return nil
end

local function isClickOnPowerMenu(x, y)
    if x >= 2 and x <= 16 then
        if y == 8 then
            return "shutdown"
        elseif y == 9 then
            return "reboot"
        elseif y == 10 then
            return "lock"
        end
    end
    return nil
end

local function launchApp(command)
    term.clear()
    term.setCursorPos(1, 1)

    if command == "/disk/os/home.lua" or command == "/disk/os/programs" then
        shell.run(command)
    elseif command == "showPowerMenu" then
        drawPowerMenu()
        drawNavBar()  -- Ensure navbar is redrawn
        local event, _, x, y = os.pullEvent("mouse_click")

        local powerMenuCommand = isClickOnPowerMenu(x, y)
        if powerMenuCommand then
            if powerMenuCommand == "shutdown" then
                os.shutdown()
            elseif powerMenuCommand == "reboot" then
                os.reboot()
            elseif powerMenuCommand == "lock" then
                shell.run("/disk/os/lock")
            end
        end
    else
        shell.run("start " .. command)
    end

    -- Redraw navbar after app exits
    drawNavBar()
end

local function homescreen()
    while true do
        drawHomescreen()
        drawNavBar()  -- Draw the navigation bar
        local event, _, x, y = os.pullEvent("mouse_click")

        if event == "mouse_click" then
            local command = isClickOnButton(x, y)
            if command then
                launchApp(command)
            end
        end
    end
end

-- Redraw the navbar at regular intervals
local function keepNavBarVisible()
    while true do
        drawNavBar()
        sleep(1)
    end
end

parallel.waitForAny(homescreen, keepNavBarVisible)