local protobuf = require("pb")
local pairs = pairs
local ipairs = ipairs
local type = type
local getmetatable = getmetatable
local assert = assert
local enums = {}

local function toEnumInt(name, T, str)
  local t = enums[T]
  if t then
    local v = t[str]
    if v then
      return v
    end
  else
    t = {}
    enums[T] = t
  end
  for _, cls in pairs(T) do
    if cls.class == "E" then
      local v = cls[str]
      if v then
        t[str] = v
        return v
      end
    end
  end
  assert(false, str .. " is not in " .. name)
end

local function parse(T, t, proto, name)
  local attrArr = System.typeof(T):GetCustomAttributes(System.typeof(ProtoBuf.ProtoAfterDeserializationAttribute), false)
  if #attrArr > 0 then
    local attr = attrArr:get(0)
    attr:GetType():getDeclaringMethod():Invoke(t, nil)
  end
  for k, v in pairs(proto) do
    if type(v) == "table" then
      local value = t[k]
      if value ~= nil then
        local meta = getmetatable(value)
        if meta ~= nil and meta.__genericT__ ~= nil then
          local class = meta.__genericT__
            for _, v1 in pairs(v) do
              if type(v1) == "table" then
                local instance = class()
                parse(class, instance, v1, name)
                value:Add(instance)
              else
                value:Add(v1)
              end
            end
        else
            local instance = value()
            parse(value, instance, v, name)
            t[k] = instance
        end
      else
        t[k] = v
      end
    else
       --is enum string
      if type(v) == "string" and type(T[k]) == "number" then
        v = toEnumInt(name, T, v)
      end
      t[k] = v
    end
  end
  local metadata = rawget(T, "__metadata__")
  local methodMeta =  metadata and metadata.methods
  if methodMeta then
    for index, value in ipairs(methodMeta) do
      if getmetatable(value[4]).__name=="ProtoBuf.ProtoAfterDeserializationAttribute" then
        t[value[1]](t)
      end
    end
  end
end

local function decode(name, data)
  local proto, error = protobuf.decode(name, data)
  assert(proto, error)
  local T = System.getClass(name)
  local t = T()
  parse(T, t, proto, name)
  return t
end

function encodeProtobuf(t)
  local name = t.__name__
  return protobuf.encode(name, t)
end

function decodeProtobuf(data, T)
  return decode(T.__name__, data)
end

function decodeProtobuf1(data, TName)
  return decode(TName, data)
end