termutils = {}

-- Clears the terminal and resets the cursor position
termutils.clear = function()
  term.clear()
  term.setCursorPos(1, 1)
end

-- Resets text and background colors to default
termutils.clearColor = function()
  term.setTextColor(colors.white)
  term.setBackgroundColor(colors.black)
end

-- Prompts the user for input and returns the entered value
function input()
  term.setTextColor(colors.blue)
  local dir = shell.dir() .. "/> "
  write(dir)
  termutils.clearColor()
  return io.read()
end

-- Function to trim any trailing slashes from a path
local function trimTrailingSlash(path)
  return path:match("^(.-)/?$") -- Ensure leading slash is maintained
end

-- Checks if the command involves protected paths or files and handles protection
function checkProtection(command)
  local blockedCommands = { "sh", "shell" }
  local protectedPaths = {
    "/disk/boot/",
    "/disk/os/",
    "/disk/bootloader/",
    "/disk/users/",
    "/recovery/",       -- Directory path
    "/disk/ACPI/",      -- Directory path
    "/disk/error/",     -- Directory path
    "/disk/startup",    -- Directory path
    "/disk/setup",      -- Directory path
    "/disk/install.lua", -- File path
    "/disk/install-assist", -- File path
    "startup",          -- File name
    "no-os",            -- File name
    "dev.cfg"           -- File name
  }

  -- Handle specific commands for reboot and shutdown
  if command:lower() == "reboot" then
    executeCommand("/disk/ACPI/reboot")
    return false -- Prevent further command processing
  elseif command:lower() == "shutdown" then
    executeCommand("/disk/ACPI/shutdown")
    return false -- Prevent further command processing
  end

  -- Block specific commands
  for _, blocked in ipairs(blockedCommands) do
    if command:lower() == blocked then
      print("Error: The command '" .. blocked .. "' is not allowed.")
      return false
    end
  end

  -- Check for protected paths/files
  for _, path in ipairs(protectedPaths) do
    if isInProtectedPath(command, path) then
      if checkDevConfig() then
        print("Failed to verify system... continuing with shell command")
      end
      if not requestAdminCredentials() then
        return false
      end
      print("Warning: This command may modify critical files. Proceed with caution.")
      return true
    end
  end

  return true
end

-- Checks if the command involves a protected path or its subdirectories
function isInProtectedPath(command, path)
  -- Ensure the command has a leading slash
  if not command:match("^/") then
    command = "/" .. command
  end

  -- Ensure path has a leading slash
  local protectedPath = trimTrailingSlash(path)
  if not protectedPath:match("^/") then
    protectedPath = "/" .. protectedPath
  end

  -- Check if the command involves modifying protected paths or files
  return command:find("^" .. protectedPath, 1, true) ~= nil
end

-- Requests admin credentials from the user
function requestAdminCredentials()
  termutils.clear()

  local width, height = term.getSize()
  local boxWidth = 40
  local boxHeight = 10
  local startX = math.floor((width - boxWidth) / 2)
  local startY = math.floor((height - boxHeight) / 2)

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

  -- Draw the box
  term.setCursorPos(startX, startY)
  write("+" .. string.rep("-", boxWidth - 2) .. "+")

  for y = startY + 1, startY + boxHeight - 1 do
    term.setCursorPos(startX, y)
    write("|" .. string.rep(" ", boxWidth - 2) .. "|")
  end

  term.setCursorPos(startX, startY + boxHeight)
  write("+" .. string.rep("-", boxWidth - 2) .. "+")

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

  -- Display prompts inside the box
  local contentX = startX + 2
  local contentY = startY + 2

  term.setCursorPos(contentX, contentY)
  write("Doggy OS File System Protection")

  term.setCursorPos(contentX, contentY + 2)
  write("Enter Administrator login.")

  term.setCursorPos(contentX, contentY + 4)
  write("Username: ")
  local username = io.read()

  term.setCursorPos(contentX, contentY + 6)
  write("Password: ")
  term.setTextColor(colors.black) -- Change text color to black to hide the input
  local password = io.read()
  term.setTextColor(colors.white) -- Reset text color

  -- Verify credentials and handle access
  local isVerified = verifyPassword(username, password)
  if not isVerified then
    termutils.clear() -- Clear the screen if verification fails
  end
  return isVerified
end

-- Verifies the entered username and password
function verifyPassword(username, password)
  local passwordFilePath = "/disk/users/" .. username .. "/password.txt"
  local file = fs.open(passwordFilePath, "r")

  if file then
    local correctPassword = file.readAll()
    file.close()

    if password == correctPassword and userIsAdmin(username) then
      return true
    else
      print("Invalid credentials or insufficient privileges.")
      return false
    end
  else
    print("User not found.")
    return false
  end
end

-- Checks if the user has admin privileges
function userIsAdmin(username)
  local adminFilePath = "/disk/users/" .. username .. "/admin.txt"
  local file = fs.open(adminFilePath, "r")

  if file then
    file.close()
    return true
  else
    return false
  end
end

-- Executes the command with error handling
function executeCommand(command)
  local success, err = pcall(function() shell.run(command) end)
  if not success then
    print("Error executing command:", err)
  end
end

-- Checks if dev.cfg exists in the root directory
function checkDevConfig()
  local file = fs.open("/dev.cfg", "r")
  if file then
    file.close()
    return true
  else
    return false
  end
end

-- Main execution starts here
termutils.clear()
print("Doggy OS Terminal (13.0)")

while true do
  local command = input()

  if checkProtection(command) then
    executeCommand(command)
  else
    print("Command aborted.")
  end
end