-- Lua snippet to display what branches were affected by revisions and certs
-- that came into the database.  I integrate it into my ~/.monotone/monotonerc
-- /Richard Levitte
--
-- Released as public domain

do
   netsync_branches = {}

   function RL_note_netsync_cert_received(direction,rev_id,key,name,value,nonce)
      if name == "branch" then
         if netsync_branches[direction][nonce][value] == nil then
            netsync_branches[direction][nonce][value] = 1
         else
            netsync_branches[direction][nonce][value] =
               netsync_branches[direction][nonce][value] + 1
         end
      end
   end

   notifier = {
      ["start"] =
         function(session_id,...)
            netsync_branches["received"] = {}
            netsync_branches["sent"] = {}
            netsync_branches["received"][session_id] = {}
            netsync_branches["sent"][session_id] = {}
            return "continue",nil
         end,
      ["revision_received"] =
         function(new_id,revision,certs,session_id)
            for _, item in pairs(certs) do
               RL_note_netsync_cert_received("received",
                                             new_id,
                                             item.key,
                                             item.name,
                                             item.value,
                                             session_id)
            end
            return "continue",nil
         end,
      ["revision_sent"] =
         function(new_id,revision,certs,session_id)
            for _, item in pairs(certs) do
               RL_note_netsync_cert_received("sent",
                                             new_id,
                                             item.key,
                                             item.name,
                                             item.value,
                                             session_id)
            end
            return "continue",nil
         end,
      ["cert_received"] =
         function(rev_id,key,name,value,session_id)
            RL_note_netsync_cert_received("received",
                                          rev_id,
                                          key,name,value,
                                          session_id)
            return "continue",nil
         end,
      ["cert_sent"] =
         function(rev_id,key,name,value,session_id)
            RL_note_netsync_cert_received("sent",
                                          rev_id,
                                          key,name,value,
                                          session_id)
            return "continue",nil
         end,
      ["end"] =
         function(session_id,status)
            -- only try to display results if we got
            -- at least partial contents
            if status > 211 then
               return "continue",nil
            end

            local first = true
            for item, amount in pairs(netsync_branches["received"][session_id])
            do
               if first then
                  io.stderr:write("Received data on branches:\n")
                  first = false
               end
               io.stderr:write("  ",item,"  (",amount,")\n")   
            end
            netsync_branches["received"][session_id] = nil

            first = true
            for item, amount in pairs(netsync_branches["sent"][session_id])
            do
               if first then
                  io.stderr:write("Sent data on branches:\n")
                  first = false
               end
               io.stderr:write("  ",item,"  (",amount,")\n")   
            end
            netsync_branches["sent"][session_id] = nil
            return "continue",nil
         end
   }

   local v,m = push_hook_functions(notifier)
   if not v then
      error(m)
   elseif m then
      io.stderr:write("Warning: ",m,"\n")
   end
end