--[[

This example client-side loose Extension runs before a 'p4 add'
command and checks that the files being added are not over an
arbitrary size limit.

]]--

local maxSize = 123

function fileSize( name )
  local fh = io.open( name, "rb" )
  if fh == nil then
    return -1
  end
  local size = fh:seek( "end" )
  fh:close()
  return size
end

--[[

Client-side Extensions have two callbacks that they can define - one to
run before a command is executed, and one afterwards.  The preCommand
callback function can choose to 0) let the command PASS and continue to
run, 1) REPLACE the command (pretend the command ran but not actually do it
on the assumption that the Extension did something in its place), or 2)
FAIL the command.  The postCommand hook can only FAIL and PASS.

]]--

function preCommand()
  local func = Helix.Core.Client.GetVar( "func" )

  -- The callbacks are run for every command, so check that this is a 'p4 add'.
  if func ~= "add" then
    return Helix.Core.Client.Action.PASS
  end

  local argc = Helix.Core.Client.GetVar( "argc" )
  local argv = Helix.Core.Client.GetVar( "argv" )
  local msg = ""

  for i, v in ipairs( argv ) do
    local fileSize = fileSize( v )
    if fileSize > maxSize then
      msg = msg .. v .. " " .. fileSize
      if i < argc - 1 then
        msg = msg .. ", "
      end
    end
  end

  if string.len( msg ) > 0 then
    msg = "Files over size limit:  " .. msg
    Helix.Core.Client.ClientError( msg )
    return Helix.Core.Client.Action.FAIL
  end

  return Helix.Core.Client.Action.PASS
end