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#pragma once
#include "schema.hpp"
#include "data.hpp"
#include <algorithm>
#include <charconv>
namespace saw {
namespace encode {
struct Args {};
}
namespace schema {
template<typename InnerSchemaStruct, typename InnerSchemaTuple>
using Args = Struct<
Member<String, "program">,
Member<InnerSchemaStruct, "args">,
Member<InnerSchemaTuple, "positionals">
>;
}
template<typename T>
class data<T, encode::Args> {
static_assert(always_false<T>,"Not supported. Use the schema::Args alias or check how it's defined.");
};
template<typename... Str, string_literal... Lits, typename... Tup>
class data<schema::Args<schema::Struct<schema::Member<Str,Lits>...>, schema::Tuple<Tup...>>, encode::Args> {
private:
int argc_;
char** argv_;
public:
data(int argc, char** argv):
argc_{argc},
argv_{argv}
{}
uint64_t size() const {
if(argc_ < 0){
return 0u;
}
static_assert(sizeof(int) <= sizeof(uint64_t), "size_t is smaller than int");
return static_cast<uint64_t>(argc_);
}
std::string_view arg_view(uint64_t i){
if(i < size()){
return std::string_view{argv_[i]};
}
return "";
}
};
namespace impl {
template<typename T, typename ToDec>
struct args_decode {
static_assert(always_false<T,ToDec>, "Not supported");
};
template<typename T, uint64_t N, typename ToDec>
struct args_decode<schema::Primitive<T,N>, ToDec> {
using Schema = schema::Primitive<T,N>;
static error_or<void> decode(data<Schema, ToDec>& to, std::string_view view){
if(view.empty()){
return make_error<err::invalid_state>("Can't decode empty data.");
}
typename native_data_type<Schema>::type val{};
auto fc_res = std::from_chars(view.data(), view.data()+view.size(), val);
if(fc_res.ec != std::errc{}){
auto err_bld = error_builder{[&](){
return std::string{"Parsing of failed: "} + std::string{view};
}};
return err_bld.template make_error<err::invalid_state>("Parsing failed. ");
}
to.set(val);
return make_void();
}
};
template<typename ToDec>
struct args_decode<schema::String, ToDec> {
using Schema = schema::String;
static error_or<void> decode(data<Schema, ToDec>& to, std::string_view view){
try{
to.set(std::string{view});
}catch(const std::exception&){
return make_error<err::out_of_memory>();
}
return make_void();
}
};
template<typename... Str, string_literal... Lits, typename... Tup, typename ToDec>
struct args_decode<schema::Args<schema::Struct<schema::Member<Str,Lits>...>,schema::Tuple<Tup...>>,ToDec> {
using Schema = schema::Args<
schema::Struct<schema::Member<Str,Lits>...>,
schema::Tuple<Tup...>
>;
using SchemaStruct = schema::Struct<schema::Member<Str,Lits>...>;
using SchemaTuple = schema::Tuple<Tup...>;
template<uint64_t i>
static error_or<void> decode_struct_member(data<SchemaStruct, ToDec>& to, std::string_view name, std::string_view value){
if constexpr ( i < sizeof...(Str) ) {
static constexpr string_literal Literal = parameter_key_pack_type<i,Lits...>::literal;
using StrT = typename parameter_pack_type<i,Str...>::type;
if(Literal.view() == name){
auto& target = to.template get<Literal>();
auto eov = args_decode<StrT, ToDec>::decode(target, value);
return eov;
}
return decode_struct_member<i+1u>(to, name, value);
}
return make_error<err::not_found>("Couldn't decode argument");
}
template<uint64_t i>
static error_or<void> decode_tuple_member(data<SchemaTuple, ToDec>& to, uint64_t ptr_i, std::string_view value){
if constexpr ( i < sizeof...(Tup) ){
if ( i == ptr_i ){
using TupT = typename parameter_pack_type<i,Tup...>::type;
auto& target = to.template get<i>();
return args_decode<TupT, ToDec>::decode(target, value);
}
return decode_tuple_member<i+1u>(to, ptr_i, value);
}
return make_error<err::invalid_state>("Too many positional arguments.");
}
static error_or<void> decode(data<Schema, encode::Args>& from, data<Schema,ToDec>& to){
if(from.size() == 0){
return make_error<err::invalid_state>();
}
to.template get<"program">().set(std::string{from.arg_view(0)});
uint64_t tuple_pos = 0;
for(size_t i = 1; i < from.size(); ++i){
auto view = from.arg_view(i);
if(view.starts_with("--")){
auto min_val = view.size() > 2u ? 2u : view.size();
view.remove_prefix(min_val);
++i;
if( i >= from.size() ){
return make_error<err::invalid_state>();
}
auto value_view = from.arg_view(i);
auto eov = decode_struct_member<0>(to.template get<"args">(), view, value_view);
if(eov.is_error()){
return eov;
}
} else {
auto eov = decode_tuple_member<0>(to.template get<"positionals">(), tuple_pos, view);
if(eov.is_error()){
return eov;
}
++tuple_pos;
}
}
if(tuple_pos != sizeof...(Tup)){
return make_error<err::invalid_state>("Didn't parse the whole set of positionals.");
}
return void_t{};
}
};
}
template<typename Schema>
class codec<Schema, encode::Args> {
public:
template<typename ToDec>
error_or<void> decode(data<Schema, encode::Args>& from, data<Schema, ToDec>& to){
/*
struct name_and_value {
std::string name;
std::string value;
};
std::string program;
std::vector<name_and_value> navs;
std::vector<std::string> positionals;
*/
auto eov = impl::args_decode<Schema,ToDec>::decode(from,to);
return eov;
}
};
}
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