Gui v3

-- Pocket Computer Desktop Environment (26 x 20)
local w, h = term.getSize()

-- System State
local currentPage = 1
local maxPages = 2
local lastApp = nil

-- Define Desktop Apps (Distributed across pages)
local allApps = {
    -- PAGE 1
    { page = 1, name = "Shell", color = colors.cyan,   symbol = ">_",  run = function() shell.run("shell") end },
    { page = 1, name = "Edit",  color = colors.lime,   symbol = "ED",  run = function() shell.run("edit") end },
    { page = 1, name = "Files", color = colors.yellow, symbol = "LS",  run = function() shell.run("list") sleep(2) end },
    { page = 1, name = "Clock", color = colors.orange, symbol = "12",  run = function()
        term.setBackgroundColor(colors.black)
        term.clear()
        term.setCursorPos(2, 8)
        term.setTextColor(colors.yellow)
        term.write("Time: " .. textutils.formatTime(os.time(), true))
        sleep(2)
    end },
    { page = 1, name = "Off",   color = colors.red,    symbol = "OFF", run = function() os.shutdown() end },

    -- PAGE 2
    { page = 2, name = "Chat",  color = colors.purple, symbol = "MSG", run = function() print("Opening Chat...") sleep(1) end },
    { page = 2, name = "GPS",   color = colors.blue,   symbol = "GPS", run = function() print("Searching satellites...") sleep(1) end },
    { page = 2, name = "Lua",   color = colors.magenta,symbol = "LUA", run = function() shell.run("lua") end }
}

-- Forward declaration of functions
local launchApp, openSettings

-- Bottom Bar Action Buttons
local bottomButtons = {
    { label = " [<] ", x = 2,  run = function()
        if lastApp then
            launchApp(lastApp)
        end
    end },
    { label = " [O] ", x = 11, run = function()
        currentPage = 1
    end },
    { label = " [*] ", x = 20, run = function()
        openSettings()
    end }
}

-- Grid Layout Config for 3x3 per page
local cols = 3
local iconWidth = 5
local iconHeight = 2
local startX = 2
local startY = 2
local gapX = 3
local gapY = 2

-- Pre-calculate icon grid positions based on their grid index on that page
local pageCounts = {}
for _, icon in ipairs(allApps) do
    local p = icon.page
    pageCounts[p] = (pageCounts[p] or 0) + 1
    local idx = pageCounts[p] - 1

    local col = idx % cols
    local row = math.floor(idx / cols)
    icon.x = startX + col * (iconWidth + gapX)
    icon.y = startY + row * (iconHeight + gapY)
end

-- Settings Sub-App
function openSettings()
    term.setBackgroundColor(colors.gray)
    term.clear()
    term.setTextColor(colors.white)

    term.setCursorPos(2, 2)
    term.write("--- Settings ---")
    term.setCursorPos(2, 4)
    term.write("ID: " .. os.getComputerID())
    term.setCursorPos(2, 5)
    term.write("Label: " .. (os.getComputerLabel() or "Unlabeled"))
    term.setCursorPos(2, 6)
    term.write("Modem: " .. (peripheral.find("modem") and "Online" or "None"))

    term.setTextColor(colors.yellow)
    term.setCursorPos(2, 18)
    term.write("Tap anywhere to exit")

    os.pullEvent("mouse_click")
end

-- Helper to launch apps safely and track history
function launchApp(icon)
    lastApp = icon
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.clear()
    term.setCursorPos(1, 1)
    icon.run()
end

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

    -- 1. Draw App Grid for Current Page
    for _, icon in ipairs(allApps) do
        if icon.page == currentPage then
            -- Top row of 5x2 square icon
            term.setBackgroundColor(icon.color)
            term.setTextColor(colors.white)
            term.setCursorPos(icon.x, icon.y)
            term.write(string.format(" %-3s ", icon.symbol))

            -- Bottom row of 5x2 square icon
            term.setCursorPos(icon.x, icon.y + 1)
            term.write("     ")

            -- Icon Label
            term.setBackgroundColor(colors.black)
            term.setTextColor(colors.lightGray)
            term.setCursorPos(icon.x, icon.y + 2)
            term.write(string.sub(icon.name .. "     ", 1, iconWidth))
        end
    end

    -- 2. Draw Page Indicator Dots (above bottom bar, row 18)
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.gray)
    term.setCursorPos(11, 18)
    local pageDots = ""
    for p = 1, maxPages do
        if p == currentPage then
            pageDots = pageDots .. "o "
        else
            pageDots = pageDots .. ". "
        end
    end
    term.write(pageDots)

    -- 3. Draw Bottom Navigation Bar
    term.setBackgroundColor(colors.gray)
    term.setTextColor(colors.white)
    term.setCursorPos(1, h)
    term.write(string.rep(" ", w))

    for _, btn in ipairs(bottomButtons) do
        term.setCursorPos(btn.x, h)
        term.write(btn.label)
    end
end

-- Main Event Loop
while true do
    drawDesktop()

    local event, p1, p2, p3 = os.pullEvent()

    -- 1. Handle Mouse Clicks
    if event == "mouse_click" and p1 == 1 then
        local clickX, clickY = p2, p3

        -- Check App Icons on current page
        for _, icon in ipairs(allApps) do
            if icon.page == currentPage then
                if clickX >= icon.x and clickX < (icon.x + iconWidth) and
                   clickY >= icon.y and clickY <= (icon.y + 1) then

                    -- Tap Highlight Effect
                    term.setBackgroundColor(colors.white)
                    term.setTextColor(colors.black)
                    term.setCursorPos(icon.x, icon.y)
                    term.write(string.format(" %-3s ", icon.symbol))
                    term.setCursorPos(icon.x, icon.y + 1)
                    term.write("     ")
                    sleep(0.08)

                    launchApp(icon)
                    break
                end
            end
        end

        -- Check Bottom Navigation Bar
        if clickY == h then
            for _, btn in ipairs(bottomButtons) do
                if clickX >= btn.x and clickX < (btn.x + #btn.label) then
                    btn.run()
                    break
                end
            end
        end

    -- 2. Handle Mouse Scroll (Page Switching)
    elseif event == "mouse_scroll" then
        local direction = p1
        if direction > 0 and currentPage < maxPages then
            currentPage = currentPage + 1 -- Scroll Down -> Next Page
        elseif direction < 0 and currentPage > 1 then
            currentPage = currentPage - 1 -- Scroll Up -> Prev Page
        end
    end
end