Update oppm.lua to make it install itself from loot disk

Too many reports of OPPM not working due to the floppy being read-only.

src/main/resources/assets/opencomputers/loot/OPPM/oppm.lua

@@ -480,18 +480,82 @@ local function updatePackage(pack)
   end
 end
 
-if args[1] == "list" then
-  local packs = listPackages(args[2])
-  printPackages(packs)
-elseif args[1] == "info" then
-  provideInfo(args[2])
-elseif args[1] == "install" then
-  installPackage(args[2],args[3],false)
-elseif args[1] == "update" then
-  updatePackage(args[2])
-elseif args[1] == "uninstall" then
-  uninstallPackage(args[2])
-else
-  printUsage()
+if options.iKnowWhatIAmDoing then
+  if args[1] == "list" then
+    local packs = listPackages(args[2])
+    printPackages(packs)
+  elseif args[1] == "info" then
+    provideInfo(args[2])
+  elseif args[1] == "install" then
+    installPackage(args[2],args[3],false)
+  elseif args[1] == "update" then
+    updatePackage(args[2])
+  elseif args[1] == "uninstall" then
+    uninstallPackage(args[2])
+  else
+    printUsage()
+    return
+  end
   return
 end
+
+--Very much not stolen from Sangar's install.lua
+
+local computer = require("computer")
+local unicode = require("unicode")
+
+local candidates = {}
+for address in component.list("filesystem") do
+  local dev = component.proxy(address)
+  if not dev.isReadOnly() and dev.address ~= computer.tmpAddress() then
+    table.insert(candidates, dev)
+  end
+end
+
+if #candidates == 0 then
+  print("No writable disks found, aborting.")
+  return
+end
+
+for i = 1, #candidates do
+  local label = candidates[i].getLabel()
+  if label then
+    label = label .. " (" .. candidates[i].address:sub(1, 8) .. "...)"
+  else
+    label = candidates[i].address
+  end
+  print(i .. ") " .. label)
+end
+
+print("To select the device to install to, please enter a number between 1 and " .. #candidates .. ".")
+print("Press 'q' to cancel the installation.")
+local choice
+while not choice do
+  result = io.read()
+  if result:sub(1, 1):lower() == "q" then
+    return
+  end
+  local number = tonumber(result)
+  if number and number > 0 and number <= #candidates then
+    choice = candidates[number]
+  else
+    print("Invalid input, please try again.")
+  end
+end
+candidates = nil
+
+print("Installing OpenOS to device " .. (choice.getLabel() or choice.address))
+os.sleep(0.25)
+local mnt = choice.address:sub(1, 3)
+local result, reason = shell.execute("oppm", nil, "install", "-f", "oppm", "/mnt/" .. mnt .. "/usr/", "--iKnowWhatIAmDoing")
+if not result then
+  error(reason, 0)
+end
+
+print("All done! Reboot now? [Y/n]")
+local result = io.read()
+if not result or result == "" or result:sub(1, 1):lower() == "y" then
+  print("\nRebooting now!")
+  computer.shutdown(true)
+end
+print("Returning to shell.")