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#pragma once
#include "schema.hpp"
#include "data.hpp"
#include <algorithm>
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:
char** argv_;
int argc_;
public:
data(char** argv, int argc):
argv_{argv},
argc_{argc}
{}
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... 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<Schema, 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;
if(Literal.view() == name){
auto& target = to.template get<Literal>();
/// @TODO
return void_t{};
}
return decode_struct_member<i+1u>(to, name, value);
}
return make_error<err::not_found>{"Couldn't decode argument"};
}
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)});
std::size_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">(), view);
if(eov.is_error()){
return eov;
}
++tuple_pos;
}
}
if(tuple_pos != sizeof...(Tup)){
return make_error<err::invalid_state>();
}
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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