-- --
-- --------------------------------------------------------------------------------
-- --  FILE:  encoder.lua
-- --  DESCRIPTION:  protoc-gen-lua
-- --      Google's Protocol Buffers project, ported to lua.
-- --      https://code.google.com/p/protoc-gen-lua/
-- --
-- --      Copyright (c) 2010 , 林卓毅 (Zhuoyi Lin) netsnail@gmail.com
-- --      All rights reserved.
-- --
-- --      Use, modification and distribution are subject to the "New BSD License"
-- --      as listed at <url: http://www.opensource.org/licenses/bsd-license.php >.
-- --
-- --  COMPANY:  NetEase
-- --  CREATED:  2010年07月29日 19时30分46秒 CST
-- --------------------------------------------------------------------------------
-- --
-- local string = string
-- local table = table
-- local ipairs = ipairs
-- local assert =assert

-- local pb = require "pb"
-- local wire_format = require "protobuf.wire_format"
-- module "protobuf.encoder"

-- function _VarintSize(value)
--     if value <= 0x7f then return 1 end
--     if value <= 0x3fff then return 2 end
--     if value <= 0x1fffff then return 3 end
--     if value <= 0xfffffff then return 4 end
--     return 5 
-- end

-- function _SignedVarintSize(value)
--     if value < 0 then return 10 end
--     if value <= 0x7f then return 1 end
--     if value <= 0x3fff then return 2 end
--     if value <= 0x1fffff then return 3 end
--     if value <= 0xfffffff then return 4 end
--     return 5
-- end

-- function _TagSize(field_number)
--   return _VarintSize(wire_format.PackTag(field_number, 0))
-- end

-- function _SimpleSizer(compute_value_size)
--     return function(field_number, is_repeated, is_packed)
--         local tag_size = _TagSize(field_number)
--         if is_packed then
--             local VarintSize = _VarintSize
--             return function(value)
--                 local result = 0
--                 for _, element in ipairs(value) do
--                     result = result + compute_value_size(element)
--                 end
--                 return result + VarintSize(result) + tag_size
--             end
--         elseif is_repeated then
--             return function(value)
--                 local result = tag_size * #value
--                 for _, element in ipairs(value) do
--                     result = result + compute_value_size(element)
--                 end
--                 return result
--             end
--         else
--             return function (value)
--                 return tag_size + compute_value_size(value)
--             end
--         end
--     end
-- end

-- function _ModifiedSizer(compute_value_size, modify_value)
--     return function (field_number, is_repeated, is_packed)
--         local tag_size = _TagSize(field_number)
--         if is_packed then
--             local VarintSize = _VarintSize
--             return function (value)
--                 local result = 0
--                 for _, element in ipairs(value) do
--                     result = result + compute_value_size(modify_value(element))
--                 end
--                 return result + VarintSize(result) + tag_size
--             end
--         elseif is_repeated then
--             return function (value)
--                 local result = tag_size * #value
--                 for _, element in ipairs(value) do
--                     result = result + compute_value_size(modify_value(element))
--                 end
--                 return result
--             end
--         else
--             return function (value)
--                 return tag_size + compute_value_size(modify_value(value))
--             end
--         end
--     end
-- end

-- function _FixedSizer(value_size)
--     return function (field_number, is_repeated, is_packed)
--         local tag_size = _TagSize(field_number)
--         if is_packed then
--             local VarintSize = _VarintSize
--             return function (value)
--                 local result = #value * value_size
--                 return result + VarintSize(result) + tag_size
--             end
--         elseif is_repeated then
--             local element_size = value_size + tag_size
--             return function(value)
--                 return #value * element_size
--             end
--         else
--             local field_size = value_size + tag_size
--             return function (value)
--                 return field_size
--             end
--         end
--     end
-- end

-- Int32Sizer = _SimpleSizer(_SignedVarintSize)
-- Int64Sizer = Int32Sizer
-- EnumSizer = Int32Sizer

-- UInt32Sizer = _SimpleSizer(_VarintSize)
-- UInt64Sizer = UInt32Sizer 

-- SInt32Sizer = _ModifiedSizer(_SignedVarintSize, wire_format.ZigZagEncode)
-- SInt64Sizer = SInt32Sizer

-- Fixed32Sizer = _FixedSizer(4) 
-- SFixed32Sizer = Fixed32Sizer
-- FloatSizer = Fixed32Sizer

-- Fixed64Sizer = _FixedSizer(8) 
-- SFixed64Sizer = Fixed64Sizer
-- DoubleSizer = Fixed64Sizer

-- BoolSizer = _FixedSizer(1)


-- function StringSizer(field_number, is_repeated, is_packed)
--     local tag_size = _TagSize(field_number)
--     local VarintSize = _VarintSize
--     assert(not is_packed)
--     if is_repeated then
--         return function(value)
--             local result = tag_size * #value
--             for _, element in ipairs(value) do
--                 local l = #element
--                 result = result + VarintSize(l) + l
--             end
--             return result
--         end
--     else
--         return function(value)
--             local l = #value
--             return tag_size + VarintSize(l) + l
--         end
--     end
-- end

-- function BytesSizer(field_number, is_repeated, is_packed)
--     local tag_size = _TagSize(field_number)
--     local VarintSize = _VarintSize
--     assert(not is_packed)
--     if is_repeated then
--         return function (value)
--             local result = tag_size * #value
--             for _,element in ipairs(value) do
--                 local l = #element
--                 result = result + VarintSize(l) + l
--             end
--             return result
--         end
--     else
--         return function (value)
--             local l = #value
--             return tag_size + VarintSize(l) + l
--         end
--     end
-- end

-- function MessageSizer(field_number, is_repeated, is_packed)
--     local tag_size = _TagSize(field_number)
--     local VarintSize = _VarintSize
--     assert(not is_packed)
--     if is_repeated then
--         return function(value)
--             local result = tag_size * #value
--             for _,element in ipairs(value) do
--                 local l = element:ByteSize()
--                 result = result + VarintSize(l) + l
--             end
--             return result
--         end
--     else
--         return function (value)
--             local l = value:ByteSize()
--             return tag_size + VarintSize(l) + l
--         end
--     end
-- end


-- -- ====================================================================
-- --  Encoders!

-- local _EncodeVarint = pb.varint_encoder
-- local _EncodeSignedVarint = pb.signed_varint_encoder
-- local _EncodeVarint64 = pb.varint_encoder64
-- local _EncodeSignedVarint64 = pb.signed_varint_encoder64


-- function _VarintBytes(value)
--     local out = {}
--     local write = function(value)
--         out[#out + 1 ] = value
--     end
--     _EncodeSignedVarint(write, value)
--     return table.concat(out)
-- end

-- function TagBytes(field_number, wire_type)
--   return _VarintBytes(wire_format.PackTag(field_number, wire_type))
-- end

-- function _SimpleEncoder(wire_type, encode_value, compute_value_size)
--     return function(field_number, is_repeated, is_packed)
--         if is_packed then
--             local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
--             local EncodeVarint = _EncodeVarint
--             return function(write, value)
--                 write(tag_bytes)
--                 local size = 0
--                 for _, element in ipairs(value) do
--                     size = size + compute_value_size(element)
--                 end
--                 EncodeVarint(write, size)
--                 for element in value do
--                     encode_value(write, element)
--                 end
--             end
--         elseif is_repeated then
--             local tag_bytes = TagBytes(field_number, wire_type)
--             return function(write, value)
--                 for _, element in ipairs(value) do
--                     write(tag_bytes)
--                     encode_value(write, element)
--                 end
--             end
--         else
--             local tag_bytes = TagBytes(field_number, wire_type)
--             return function(write, value)
--                 write(tag_bytes)
--                 encode_value(write, value)
--             end
--         end
--     end
-- end

-- function _ModifiedEncoder(wire_type, encode_value, compute_value_size, modify_value)
--     return function (field_number, is_repeated, is_packed)
--         if is_packed then
--             local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
--             local EncodeVarint = _EncodeVarint
--             return function (write, value)
--                 write(tag_bytes)
--                 local size = 0
--                 for _, element in ipairs(value) do
--                     size = size + compute_value_size(modify_value(element))
--                 end
--                 EncodeVarint(write, size)
--                 for _, element in ipairs(value) do
--                     encode_value(write, modify_value(element))
--                 end
--             end
--         elseif is_repeated then
--             local tag_bytes = TagBytes(field_number, wire_type)
--             return function (write, value)
--                 for _, element in ipairs(value) do
--                     write(tag_bytes)
--                     encode_value(write, modify_value(element))
--                 end
--             end
--         else
--             local tag_bytes = TagBytes(field_number, wire_type)
--             return function (write, value)
--                 write(tag_bytes)
--                 encode_value(write, modify_value(value))
--             end
--         end
--     end
-- end

-- function _StructPackEncoder(wire_type, value_size, format)
--     return function(field_number, is_repeated, is_packed)
--         local struct_pack = pb.struct_pack
--         if is_packed then
--             local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
--             local EncodeVarint = _EncodeVarint
--             return function (write, value)
--                 write(tag_bytes)
--                 EncodeVarint(write, #value * value_size)
--                 for _, element in ipairs(value) do
--                     struct_pack(write, format, element)
--                 end
--             end
--         elseif is_repeated then
--             local tag_bytes = TagBytes(field_number, wire_type)
--             return function (write, value)
--                 for _, element in ipairs(value) do
--                     write(tag_bytes)
--                     struct_pack(write, format, element)
--                 end
--             end
--         else
--             local tag_bytes = TagBytes(field_number, wire_type)
--             return function (write, value)
--                 write(tag_bytes)
--                 struct_pack(write, format, value)
--             end
--         end

--     end
-- end

-- Int32Encoder = _SimpleEncoder(wire_format.WIRETYPE_VARINT, _EncodeSignedVarint, _SignedVarintSize)
-- Int64Encoder = _SimpleEncoder(wire_format.WIRETYPE_VARINT, _EncodeSignedVarint64, _SignedVarintSize)
-- EnumEncoder = Int32Encoder

-- UInt32Encoder = _SimpleEncoder(wire_format.WIRETYPE_VARINT, _EncodeVarint, _VarintSize)
-- UInt64Encoder = _SimpleEncoder(wire_format.WIRETYPE_VARINT, _EncodeVarint64, _VarintSize)

-- SInt32Encoder = _ModifiedEncoder(
--     wire_format.WIRETYPE_VARINT, _EncodeVarint, _VarintSize,
--     wire_format.ZigZagEncode32)

-- SInt64Encoder = _ModifiedEncoder(
--     wire_format.WIRETYPE_VARINT, _EncodeVarint64, _VarintSize,
--     wire_format.ZigZagEncode64)

-- Fixed32Encoder  = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('I'))
-- Fixed64Encoder  = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('Q'))
-- SFixed32Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('i'))
-- SFixed64Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('q'))
-- FloatEncoder    = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, 4, string.byte('f'))
-- DoubleEncoder   = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, 8, string.byte('d'))


-- function BoolEncoder(field_number, is_repeated, is_packed)
--     local false_byte = '\0'
--     local true_byte = '\1'
--     if is_packed then
--         local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
--         local EncodeVarint = _EncodeVarint
--         return function (write, value)
--             write(tag_bytes)
--             EncodeVarint(write, #value)
--             for _, element in ipairs(value) do
--                 if element then
--                     write(true_byte)
--                 else
--                     write(false_byte)
--                 end
--             end
--         end
--     elseif is_repeated then
--         local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_VARINT)
--         return function(write, value)
--             for _, element in ipairs(value) do
--                 write(tag_bytes)
--                 if element then
--                     write(true_byte)
--                 else
--                     write(false_byte)
--                 end
--             end
--         end
--     else
--         local tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_VARINT)
--         return function (write, value)
--             write(tag_bytes)
--             if value then
--                 return write(true_byte)
--             end
--             return write(false_byte)
--         end
--     end
-- end

-- function StringEncoder(field_number, is_repeated, is_packed)
--     local tag = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
--     local EncodeVarint = _EncodeVarint
--     assert(not is_packed)
--     if is_repeated then
--         return function (write, value)
--             for _, element in ipairs(value) do
-- --                encoded = element.encode('utf-8')
--                 write(tag)
--                 EncodeVarint(write, #element)
--                 write(element)
--             end
--         end
--     else
--         return function (write, value)
-- --            local encoded = value.encode('utf-8')
--             write(tag)
--             EncodeVarint(write, #value)
--             return write(value)
--         end
--     end
-- end

-- function BytesEncoder(field_number, is_repeated, is_packed)
--     local tag = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
--     local EncodeVarint = _EncodeVarint
--     assert(not is_packed)
--     if is_repeated then
--         return function (write, value)
--             for _, element in ipairs(value) do
--                 write(tag)
--                 EncodeVarint(write, #element)
--                 write(element)
--             end
--         end
--     else
--         return function(write, value)
--             write(tag)
--             EncodeVarint(write, #value)
--             return write(value)
--         end
--     end
-- end


-- function MessageEncoder(field_number, is_repeated, is_packed)
--     local tag = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
--     local EncodeVarint = _EncodeVarint
--     assert(not is_packed)
--     if is_repeated then
--         return function(write, value)
--             for _, element in ipairs(value) do
--                 write(tag)
--                 EncodeVarint(write, element:ByteSize())
--                 element:_InternalSerialize(write)
--             end
--         end
--     else
--         return function (write, value)
--             write(tag)
--             EncodeVarint(write, value:ByteSize())
--             return value:_InternalSerialize(write)
--         end
--     end
-- end