Configurable OPPM Repo Patch

local shell = require("shell")

local orig = [[return serial.unserialize(sRepos)]]
local repl = [[local result = serial.unserialize(sRepos)
  local config = io.open("/etc/oppm-repo.cfg","r")
  if config then
    config:close()
    for line in io.lines("/etc/oppm-repo.cfg") do
      result[line] = {repo=line}
    end
  end
  return result]]

function escape(str)
    return str:gsub("[%(%)%.%%%+%-%*%?%[%]%^%$]", function(c) return "%" .. c end)
end

local path, revert = ...
if path == "revert" then
  revert = true
  path = nil
end

if not path then
  path = shell.resolve("oppm.lua", shell.getPath())
  if not path then
    print("oppm.lua not found")
    os.exit(1)
    return
  end
end

local file = io.open(path, "rb")
if not file then
  print("File not found: " .. path)
  os.exit(1)
  return
end

print("Patching the file " .. path)

local content = file:read("*a")
file:close()

local pattern = nil
if revert then
  pattern = escape(repl)
  repl = orig
else
  pattern = escape(orig)
end

local patched = content:gsub(pattern, repl)

if patched == content then
  print("The file was not changed!")
  return
end

file = io.open(path, "w")
file:write(patched)
file:close()

print("The file was patched successfully")

file = io.open("/etc/oppm-repo.cfg", "a")
file:close()