-- Doggy OS Boot Manager for CC Tweaked

local w, h = term.getSize()

-- Function to center text horizontally
local function centerText(y, text)
    local x = math.floor((w - #text) / 2)
    term.setCursorPos(x, y)
    term.write(text)
end

-- ASCII art dog image
local dogImage = {
    "     |\\_/|                  ",
    "     | @ @   Doggy OS        ",
    "     |   <>              _   ",
    "     |  _/\\------____ ((| |))",
    "     |               `--' |  ",
    " _____|_       ___|   |___.' ",
    "/_/_____/____/_______|       "
}

-- Function to draw the ASCII art
local function drawASCIIArt(y, textColor)
    term.setTextColor(textColor)
    for i, line in ipairs(dogImage) do
        centerText(y + i - 1, line)
    end
end

-- Function to display the "Insert bootable medium" message
local function insertBootableMediumMessage()
    local message = "Insert bootable medium"
    local messageY = h - 5  -- Move the message higher (adjusted position)

    while true do
        term.setBackgroundColor(colors.black)
        term.clear()

        -- Draw the ASCII art
        drawASCIIArt(math.floor((h - #dogImage) / 2), colors.white)

        -- Center and display the message
        centerText(messageY, message)

        -- Wait briefly before clearing and redrawing
        os.sleep(1)
    end
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.blue)
    term.setBackgroundColor(colors.black)

    -- Draw Header
    term.setCursorPos(1, 1)
    term.write("  ***** Doggy OS Boot Manager *****  ")

    term.setCursorPos(1, 3)
    term.setTextColor(colors.lightGray)
    term.write("Use Arrow keys to navigate, Enter to boot")

    term.setCursorPos(1, 5)
    term.setTextColor(colors.gray)
    term.write("======================================")

    -- Draw boot options
    for i, disk in ipairs(disks) do
        term.setCursorPos(1, 6 + i)
        if i == selected then
            term.setTextColor(colors.white)
            term.setBackgroundColor(colors.blue)
        else
            term.setTextColor(colors.lightGray)
            term.setBackgroundColor(colors.black)
        end
        term.write(" [" .. i .. "] " .. disk.displayName)
        term.setTextColor(colors.white)  -- Reset text color after writing
    end

    term.setTextColor(colors.white)
    term.setBackgroundColor(colors.black)

    term.setCursorPos(1, 6 + #disks + 7)
    term.setTextColor(colors.gray)
    term.write("======================================")

    -- Display booting message if available
    if bootingMessage then
        term.setCursorPos(1, 8 + #disks + 7)
        term.setTextColor(colors.cyan)
        term.write(bootingMessage)
    end
end

local function main()
    local disks
    while true do
        disks = findStartupFiles()
        if #disks > 0 then
            break
        end
        -- No boot files found, display the "Insert bootable medium" screen
        insertBootableMediumMessage()
    end

    local selected = 1
    drawMenu(disks, selected, nil)

    while true do
        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 then
            -- Update the GUI to show booting message
            drawMenu(disks, selected, "Booting from " .. disks[selected].path .. "...")
            sleep(1)  -- Wait for a second to display the booting message

            -- Set text color to white and background color to black before booting
            term.setTextColor(colors.white)
            term.setBackgroundColor(colors.black)

            -- Boot the selected OS
            shell.run(disks[selected].path)
            break
        end
        drawMenu(disks, selected, nil)  -- Refresh the menu without booting message
    end
end

main()