#pragma once

#include <forstio/codec/schema.h>

#include <iostream>

namespace saw {
namespace impl {
struct cli_mode {
	struct read {};
	struct write {};
};

template<typename T, typename Encoding>
struct cli_traverser {
	static_assert(always_false<T,Encoding>, "Not supported");
};

template<typename Schema, typename Encoding>
struct cli_modifier {
	codec<Schema, encode::Json> json;
	codec<Schema, Encoding> encoded;

	error_or<void> read(
					std::deque<std::string>& sch_path,
					data<Schema, Encoding>& enc_data, 
					std::string& json_data_str
					){
		data<Schema, encode::Native> native;
		if constexpr ( std::is_same_v<Encoding, encode::Native> ){
			auto eov = encoded.decode<encode::Native>(enc_data, native);
			if(eov.is_error()){
				return eov;
			}
		}else{
				native = enc_data;
		}
		{
			data<Schema, encode::Json> json_data;
			auto eov = json.encode<encode::Native>(native, json_data);
			if(eov.is_error()){
				return eov;
			}

			json_data_str = convert_to_string(json_data.get_buffer());

			std::cout<<json_data_str<<std::endl;
		}

		return void_t{};
	}
	
	error_or<void> write(
					std::deque<std::string>& sch_path,
					data<Schema, Encoding>& enc_data,
					std::string& json_data_str
					){
		data<Schema, encode::Native> native;
		{
			/// @todo string to data
			data<Schema, encode::Json> json_data{ std::string_view{json_data_str} };
			auto eov = json.decode<encode::Native>(json_data, native);
			if(eov.is_error()){
				return eov;
			}
		}
		if constexpr (std::is_same_v<Encoding, encode::Native> ){
			auto eov = encoded.encode<encode::Native>(native, enc_data);
			if(eov.is_error()){
				return eov;
			}
		}else{
				enc_data = native;
		}

		return void_t{};
	}
};

template<typename... T, typename Encoding>
struct cli_traverser<schema::Tuple<T...>, Encoding> {
		using Schema = schema::Tuple<T...>;

		template<typename Traversal, size_t i>
		static error_or<void> traverse_member(std::deque<std::string>& sch_path, data<Schema, Encoding>& enc_data, std::string& json_data){
				using Type = typename parameter_pack_type<i,T...>::type;

				std::string num_str = std::to_string(i);
				if( num_str == sch_path.front() ){
						sch_path.pop_front();
						return cli_traverser<Type, Encoding>::traverse<Traversal>(sch_path, enc_data.template get<i>(), json_data);
				}

				if ( (i+1) < sizeof...(T)){
						return traverse_member<Traversal, i+1>(sch_path, enc_data, json_data);
				}
			return make_error<err::invalid_state>("Didn't find tuple path element");
		}
};

/**
 * Traverse the path until we hit the end of the provided path
 */
template<typename... T, string_literal... Lits, typename Encoding>
struct cli_traverser<schema::Struct<schema::Member<T,Lits>...>, Encoding> {
	using Schema = schema::Struct<schema::Member<T,Lits>...>;

	template<typename Traversal, size_t i>
    static error_or<void> traverse_member(std::deque<std::string>& sch_path, data<Schema,Encoding>& enc_data, std::string& json_data){
			using Type = typename parameter_pack_type<i,T...>::type;
		    constexpr string_literal Literal = parameter_key_pack_type<i, Lits...>::literal;

			if ( Literal.view() == sch_path.front() ){
				sch_path.pop_front();
				return cli_traverser<Type>::traverse<Traversal>(sch_path, enc_data.template get<Literal>(), json_data);
			}

			if constexpr ( (i+1) < sizeof...(T) ) {
				return traverse_member<Traversal, i+1>(sch_path, enc_data, json_data);
			}
			return make_error<err::invalid_state>("Didn't find struct path element");
	}

	template<typename Traversal>
	static error_or<void> traverse(std::deque<std::string>& sch_path, data<Schema,Encoding>& enc_data, std::string& json_data){
		/**
		 * If our path is empty, then we have reached the desired destination.
		 */
		if(sch_path.empty()){
		    /**
			 * Decide during this step if we are reading or not
			 */
			cli_modifier<Schema, Encoding> mod;
			if constexpr (std::is_same_v<Traversal, cli_mode::read>){
				return mod.read(sch_path, json_data);
			} else if constexpr (std::is_same_v<Traversal, cli_mode::write>) {
				return mod.write(sch_path, json_data);
			} else {
				return make_error<err::invalid_state>("We only support cli_mode::read and cli_mode::write");
			}
		} else {
				if constexpr ( sizeof...(T) > 0 ){
						return traverse_member<Traversal, 0>(sch_path, json_data);
				}
				return make_error<err::invalid_state>("No elements in struct while path isn't empty");
		}

		return void_t{};
	}
};
}

struct parsed_args {
		bool read_mode = true;
		std::string file_path;
		std::deque<std::string> sch_path;
};

template<typename Schema, typename Encoding>
int modify_data_on_cli(bool read_mode, const std::string& file_path, std::deque<std::string> sch_path, std::string& json_data){
    /**
	 * Read data from file
	 */
	

		data<Schema, Encoding> data;
	data<Schema, encode::Native> native_data;

	if (read_mode) {
		auto eov = impl::cli_modifier<Schema, encode::Native>::traverse<impl::cli_mode::read>(sch_path, native_data, json_data);
		if(eov.is_error()){
			return -1;
		}
	} else {
		auto eov = impl::cli_modifier<Schema, encode::Native>::traverse<impl::cli_mode::write>(sch_path, native_data, json_data);
		if(eov.is_error()){
			return -1;
		}
	}

	return 0;
}
}