-- Doggy OS Boot Manager for CC Tweaked (R Key to Refresh, All White Text)

local function loadingScreen(message)
    term.clear()
    term.setCursorPos(1, 1)
    term.setTextColor(colors.white)
    print("\n\n***** Doggy OS Boot Manager *****\n")
    print(message .. "\n")
    print("Loading, please wait...\n")
    sleep(2) -- Simulate loading time
end

local function bootErrorScreen(path)
    term.clear()
    term.setCursorPos(1, 1)
    term.setTextColor(colors.white)
    print("\n\n***** Doggy OS Boot Manager *****\n")
    print("Error: Failed to boot from:\n")
    print("  " .. path .. "\n")
    print("Returning to boot menu...\n")
    sleep(3) -- Pause to show the error message
end

local function findStartupFiles()
    local disks = {}
    local diskPaths = {"/disk2", "/disk3"}  -- Include only /disk2/ and /disk3/

    -- Search for startup files in specified disk paths
    for _, diskPath in ipairs(diskPaths) do
        local paths = {
            diskPath .. "/startup",
            diskPath .. "/startup.lua",
        }
        for _, path in ipairs(paths) do
            if fs.exists(path) then
                table.insert(disks, {path = path, displayName = path})
                break
            end
        end
    end

    -- Check /disk/ for /boot/error only
    if fs.exists("/disk/boot/error") then
        table.insert(disks, {path = "/disk/boot/error", displayName = "Doggy OS"})  -- Doggy OS Device boot file
    end

    return disks
end

local function drawMenu(disks, selected, bootingMessage)
    term.clear()
    term.setCursorPos(1, 1)
    term.setTextColor(colors.white)

    -- Header Section
    print("\n\n***** Doggy OS Boot Manager *****\n")
    print("Use Arrow keys to navigate, Enter to boot, R to refresh\n")
    print("======================================\n")

    -- Boot options display
    for i, disk in ipairs(disks) do
        if i == selected then
            print("[" .. i .. "] " .. disk.displayName .. " < SELECTED >\n")
        else
            print("[" .. i .. "] " .. disk.displayName .. "\n")
        end
    end

    print("======================================\n")

    -- Display booting message if available
    if bootingMessage then
        print("\n" .. bootingMessage .. "\n")
    end
end

local function main()
    loadingScreen("Initializing Doggy OS Boot Manager")

    local selected = 1
    local disks = findStartupFiles()

    -- Continuously update boot options in a separate coroutine
    local updateDisks = coroutine.create(function()
        while true do
            local newDisks = findStartupFiles()
            if #newDisks ~= #disks then
                disks = newDisks
                if selected > #disks then
                    selected = 1
                end
                drawMenu(disks, selected, nil)
            end
            sleep(0.5)
        end
    end)

    -- Start drawing the menu
    drawMenu(disks, selected, nil)

    -- Run the coroutine to update disks and process user input
    while true do
        coroutine.resume(updateDisks)

        local event, key = os.pullEvent("key")
        if key == keys.up then
            selected = (selected - 2) % #disks + 1
        elseif key == keys.down then
            selected = selected % #disks + 1
        elseif key == keys.enter and #disks > 0 then
            -- Show booting screen
            drawMenu(disks, selected, "Booting from " .. disks[selected].path .. "...\n")
            sleep(1)  -- Pause to display booting message

            -- Attempt to boot the selected OS
            local ok, err = pcall(function()
                shell.run(disks[selected].path)
            end)

            if not ok then
                bootErrorScreen(disks[selected].path)
                drawMenu(disks, selected, nil) -- Return to menu after error
            else
                break
            end
        elseif key == keys.r then
            -- Manual refresh using R key
            disks = findStartupFiles()
            selected = math.min(selected, #disks)  -- Ensure selected remains valid
            drawMenu(disks, selected, "Boot options refreshed!\n")
        end
        drawMenu(disks, selected, nil)
    end
end

main()