From 0302bb7d3b1ab2ac936911a4466a2530650c7b83 Mon Sep 17 00:00:00 2001
From: "Claudius \"keldu\" Holeksa" <mail@keldu.de>
Date: Thu, 9 Nov 2023 21:56:18 +0100
Subject: codec-netcdf: Basic struct and primitive write in working order

---
 c++/codec-netcdf/netcdf.h      |  62 +++++++++++++++-
 c++/codec-netcdf/netcdf.tmpl.h | 156 ++++++++++++++++++++++++++++++++++++-----
 2 files changed, 198 insertions(+), 20 deletions(-)

(limited to 'c++/codec-netcdf')

diff --git a/c++/codec-netcdf/netcdf.h b/c++/codec-netcdf/netcdf.h
index 72e7614..cc9aedb 100644
--- a/c++/codec-netcdf/netcdf.h
+++ b/c++/codec-netcdf/netcdf.h
@@ -23,6 +23,8 @@ class data<Schema, encode::Netcdf> {
 private:
 		std::vector<uint8_t> buff_;
 public:
+		data() = default;
+
 		data(std::vector<uint8_t> buff):
 				buff_{std::move(buff)}
 		{}
@@ -67,8 +69,62 @@ public:
 		 * Encoder function
 		 */
 		template<typename FromEncoding>
-		error_or<void> encode() {
-				return make_error<err::not_implemented>();
+		error_or<void> encode(const data<Schema, FromEncoding>& from, data<Schema,encode::Netcdf>& to) {
+			int rc{};
+			int ncid{};
+
+			rc = nc_create_mem("forstio_internal_write_memory", 0,/*NC_NETCDF4, */0, &ncid);
+			if(rc != NC_NOERR){
+				return make_error<err::critical>();
+			}
+
+			{
+				auto eov = impl::netcdf_encode<Schema,FromEncoding>::encode_meta(from, ncid);
+				if(eov.is_error()){
+					nc_close(ncid);
+					return eov;
+				}
+			}
+
+			rc = nc_enddef(ncid);
+			if(rc != NC_NOERR){
+				nc_close(ncid);
+				return make_error<err::critical>();
+			}
+
+			{
+				auto eov = impl::netcdf_encode<Schema,FromEncoding>::encode(from, ncid);
+				if(eov.is_error()){
+					nc_close(ncid);
+					return eov;
+				}
+			}
+
+			NC_memio nc_memio;
+			rc = nc_close_memio(ncid, &nc_memio);
+			if(rc != NC_NOERR){
+				return make_error<err::critical>();
+			}
+
+			if(!nc_memio.memory || nc_memio.size == 0){
+				return make_error<err::critical>();
+			}
+
+			try {
+				to.get_data().resize(nc_memio.size);
+			}catch(const std::exception& e){
+				(void) e;
+				return make_error<err::out_of_memory>();
+			}
+
+			for(std::size_t i = 0; i < nc_memio.size; ++i){
+				to.get_data().at(i) = static_cast<uint8_t*>(nc_memio.memory)[i];
+			}
+
+			free(nc_memio.memory);
+			nc_memio.memory = nullptr;
+
+			return void_t{};
 		}
 
 		/**
@@ -79,7 +135,7 @@ public:
 				int ncid{};
 				int rc{};
 
-				rc = nc_open_mem("forstio_internal_memory", NC_NOWRITE, from_decode.get_data().size(), &from_decode.get_data()[0], &ncid);
+				rc = nc_open_mem("forstio_internal_read_memory", NC_NOWRITE, from_decode.get_data().size(), &from_decode.get_data()[0], &ncid);
 				if(rc != NC_NOERR){
 						// Don't know how to get the error, so fail critically.
 						return make_error<err::critical>();
diff --git a/c++/codec-netcdf/netcdf.tmpl.h b/c++/codec-netcdf/netcdf.tmpl.h
index f3b36b8..00bfbf4 100644
--- a/c++/codec-netcdf/netcdf.tmpl.h
+++ b/c++/codec-netcdf/netcdf.tmpl.h
@@ -48,6 +48,125 @@ struct netcdf_is_group<schema::Struct<schema::Member<T,Lits>...>> {
 };
 
 template<typename Schema, typename ToEncode>
+struct netcdf_encode;
+
+template<typename T, size_t N, typename ToEncode>
+struct netcdf_encode<schema::Primitive<T,N>, ToEncode> {
+	using Schema = schema::Primitive<T,N>;
+
+	static error_or<void> encode(const data<Schema, ToEncode>& from, int ncid, int ncvarid){
+		int rc{};
+
+		typename native_data_type<Schema>::type val = from.get();
+
+		rc = nc_put_var(ncid, ncvarid, &val);
+		if(rc != NC_NOERR) {
+			return make_error<err::critical>();
+		}
+
+		return void_t{};
+	}
+	
+	static error_or<void> encode_meta(const data<Schema, ToEncode>& from, int ncid, int ncvarid){
+		(void) from;
+		(void) ncid;
+		(void) ncvarid;
+		return void_t{};
+	}
+};
+
+template<typename... T, string_literal... Lits, typename ToEncode>
+struct netcdf_encode<schema::Struct<schema::Member<T,Lits>...>, ToEncode> {
+	using Schema = schema::Struct<schema::Member<T,Lits>...>;
+
+	template<std::size_t i>
+	static error_or<void> encode_member(const data<Schema, ToEncode>& from, int ncid){
+			using Type = typename parameter_pack_type<i,T...>::type;
+			constexpr string_literal Literal = parameter_key_pack_type<i, Lits...>::literal;
+			{
+				/**
+				 * We have to ask for the internal id of the netcdf structure
+				 */
+				if constexpr (netcdf_is_group<Type>::value){
+					return make_error<err::not_implemented>();
+				}else{
+					int nc_varid{};
+					int rc {};
+					rc = nc_inq_varid(ncid, Literal.data.data(), &nc_varid);
+					if(rc != NC_NOERR) {
+							return make_error<err::critical>();
+					}
+					auto eov = netcdf_encode<Type, ToEncode>::encode(from.template get<Literal>(), ncid, nc_varid);
+					if(eov.is_error()){
+						return eov;
+					}
+				}
+
+			}
+			if constexpr ((i+1) < sizeof...(T)){
+				auto eov = encode_member<i+1>(from, ncid);
+				if(eov.is_error()){
+						return eov;
+				}
+			}
+
+		return void_t{};
+	}
+	
+	static error_or<void> encode(const data<Schema, ToEncode>& from, int ncid){
+		if constexpr (sizeof...(T) > 0){
+				auto eov = encode_member<0>(from, ncid);
+				return eov;
+		}
+		
+		return void_t{};
+	}
+
+	template<std::size_t i>
+	static error_or<void> encode_meta_member(const data<Schema, ToEncode>& from, int ncid){
+			using Type = typename parameter_pack_type<i,T...>::type;
+			constexpr string_literal Literal = parameter_key_pack_type<i, Lits...>::literal;
+			{
+				/**
+				 * We have to ask for the internal id of the netcdf structure
+				 */
+				if constexpr (netcdf_is_group<Type>::value){
+					return make_error<err::not_implemented>();
+				}else{
+					int nc_varid{};
+					int rc {};
+					rc = nc_def_var(ncid, Literal.data.data(), netcdf_primitive_id<Type>::value, 0, nullptr, &nc_varid);
+					if(rc != NC_NOERR) {
+							return make_error<err::critical>();
+					}
+					auto eov = netcdf_encode<Type, ToEncode>::encode_meta(from.template get<Literal>(), ncid, nc_varid);
+					if(eov.is_error()){
+						return eov;
+					}
+				}
+
+			}
+			if constexpr ((i+1) < sizeof...(T)){
+				auto eov = encode_meta_member<i+1>(from, ncid);
+				if(eov.is_error()){
+						return eov;
+				}
+			}
+
+		return void_t{};
+	}
+
+	static error_or<void> encode_meta(const data<Schema, ToEncode>& from, int ncid){
+		if constexpr (sizeof...(T) > 0){
+				auto eov = encode_meta_member<0>(from, ncid);
+				return eov;
+		}
+		
+		return void_t{};
+	}
+};
+
+template<typename Schema, typename ToDecode>
 struct netcdf_decode;
 
 template<typename T, size_t N, typename ToDecode>
@@ -160,24 +279,27 @@ struct netcdf_decode<schema::Struct<schema::Member<T,Lits>...>, ToDecode> {
 				 * We have to ask for the internal id of the netcdf structure
 				 */
 				if constexpr (netcdf_is_group<Type>::value){
-						int nc_group_id{};
-						int rc {};
-						rc = nc_inq_ncid(from, Literal.data.data(), &nc_group_id);
-						if(rc != NC_NOERR) {
-								return make_error<err::critical>();
-						}
-						auto eov = netcdf_decode<Type, ToDecode>::decode(to.template get<Literal>(), nc_group_id);
-						if(eov.is_error()){
-								return eov;
-						}
+					int nc_group_id{};
+					int rc {};
+					rc = nc_inq_ncid(from, Literal.data.data(), &nc_group_id);
+					if(rc != NC_NOERR) {
+							return make_error<err::critical>();
+					}
+					auto eov = netcdf_decode<Type, ToDecode>::decode(to.template get<Literal>(), nc_group_id);
+					if(eov.is_error()){
+							return eov;
+					}
 				}else{
-						int nc_varid{};
-						int rc {};
-						rc = nc_inq_varid(from, Literal.data.data(), &nc_varid);
-						if(rc != NC_NOERR) {
-								return make_error<err::critical>();
-						}
-						auto eov = netcdf_decode<Type, ToDecode>::decode(to.template get<Literal>(), from, nc_varid); 
+					int nc_varid{};
+					int rc {};
+					rc = nc_inq_varid(from, Literal.data.data(), &nc_varid);
+					if(rc != NC_NOERR) {
+							return make_error<err::critical>();
+					}
+					auto eov = netcdf_decode<Type, ToDecode>::decode(to.template get<Literal>(), from, nc_varid); 
+					if(eov.is_error()){
+						return eov;
+					}
 				}
 
 			}
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