world_schema_json.h

#pragma once
#include "gaia/config/config.h"
 
#if GAIA_JSON_ENABLED
 
  #include <cstdio>
  #include <cstring>
 
namespace gaia {
  namespace ecs {
    namespace detail {
      inline const char* runtime_schema_kind_name(RuntimeTypeKind kind) noexcept {
        switch (kind) {
          case RuntimeTypeKind::None:
            return "none";
          case RuntimeTypeKind::Primitive:
            return "primitive";
          case RuntimeTypeKind::Struct:
            return "struct";
          case RuntimeTypeKind::Enum:
            return "enum";
          case RuntimeTypeKind::Bitmask:
            return "bitmask";
          case RuntimeTypeKind::Array:
            return "array";
          case RuntimeTypeKind::Vector:
            return "vector";
          case RuntimeTypeKind::Opaque:
            return "opaque";
        }
        return "none";
      }
 
      inline const char* runtime_schema_json_encoding_name(RuntimeJsonEncoding encoding) noexcept {
        return encoding == RuntimeJsonEncoding::Utf8String ? "utf8-string" : "default";
      }
 
      inline const char* runtime_schema_storage_name(DataStorageType storage) noexcept {
        return storage == DataStorageType::Sparse ? "sparse" : "table";
      }
 
      inline bool
      runtime_schema_type_editable(const ComponentCache& cache, const ComponentCacheItem& item, uint32_t depth = 0) {
        if (depth >= RuntimeJsonMaxDepth)
          return false;
 
        auto referenced_type_editable = [&](Entity type) {
          const auto* pType = cache.find(type);
          return pType != nullptr && runtime_schema_type_editable(cache, *pType, depth + 1);
        };
 
        switch (item.typeKind) {
          case RuntimeTypeKind::Primitive:
          case RuntimeTypeKind::Enum:
          case RuntimeTypeKind::Bitmask:
            return runtime_json_leaf_editable(item);
          case RuntimeTypeKind::Struct:
            GAIA_FOR(item.field_count()) {
              const auto& field = *item.field(i);
              if ((field.flags & (RuntimeFieldFlag_ReadOnly | RuntimeFieldFlag_Hidden)) == 0 &&
                  referenced_type_editable(field.type))
                return true;
            }
            return false;
          case RuntimeTypeKind::Array:
            return item.elementCount > 0 && referenced_type_editable(item.elementType);
          case RuntimeTypeKind::Vector:
            return item.sequenceAdapter != nullptr && item.sequenceAdapter->count != nullptr &&
                   item.sequenceAdapter->element != nullptr && referenced_type_editable(item.elementType);
          case RuntimeTypeKind::Opaque: {
            if (item.opaqueAdapter == nullptr || item.opaqueAdapter->project == nullptr)
              return false;
            const auto* pProjected = cache.find(item.opaqueAsType);
            return pProjected != nullptr &&
                   (pProjected->typeKind == RuntimeTypeKind::Struct || pProjected->typeKind == RuntimeTypeKind::Array ||
                    pProjected->typeKind == RuntimeTypeKind::Vector) &&
                   runtime_schema_type_editable(cache, *pProjected, depth + 1);
          }
          case RuntimeTypeKind::None:
            return false;
        }
        return false;
      }
 
      inline void runtime_schema_write_type_ref(ser::ser_json& writer, const ComponentCache& cache, Entity type) {
        const auto* pType = cache.find(type);
        if (pType == nullptr) {
          writer.value_null();
          return;
        }
        writer.begin_object();
        writer.key("symbol");
        const auto typeSymbol = pType->symbol_name();
        writer.value_string(typeSymbol.data(), typeSymbol.size());
        char stableId[17]{};
        (void)snprintf(stableId, sizeof(stableId), "%016llx", (unsigned long long)pType->hashLookup.hash);
        writer.key("stableId");
        writer.value_string(stableId);
        writer.end_object();
      }
 
      GAIA_NODISCARD inline bool
      runtime_schema_semantic_path(const World& world, Entity semantic, util::str& out, uint64_t& stableHash) {
        out.clear();
        stableHash = 0;
        if (semantic == EntityBad || semantic.pair())
          return false;
 
        cnt::darray_ext<util::str_view, 16> segments;
        auto current = semantic;
        while (current != EntityBad) {
          if (!world.valid(current) || current.pair())
            return false;
          const auto name = world.name(current);
          if (name.empty())
            return false;
          segments.push_back(name);
          current = world.target(current, ChildOf);
        }
        if (segments.empty())
          return false;
 
        uint32_t size = (uint32_t)segments.size() - 1;
        for (const auto segment: segments)
          size += segment.size();
        out.reserve(size);
        stableHash = core::calculate_hash64("gaia.ecs.semantic.path.v1");
        for (uint32_t i = (uint32_t)segments.size(); i > 0; --i) {
          const auto segment = segments[i - 1];
          if (!out.empty())
            out.append('.');
          out.append(segment);
          stableHash = core::hash_combine(
              stableHash, (uint64_t)segment.size(), core::calculate_hash64(segment.data(), segment.size()));
        }
        return true;
      }
 
      inline void runtime_schema_write_semantic_ref(ser::ser_json& writer, const World& world, Entity semantic) {
        util::str path;
        uint64_t stableHash = 0;
        if (!runtime_schema_semantic_path(world, semantic, path, stableHash)) {
          writer.value_null();
          return;
        }
        const auto name = world.name(semantic);
        writer.begin_object();
        writer.key("name");
        writer.value_string(name.data(), name.size());
        writer.key("path");
        writer.value_string(path.data(), path.size());
        char stableId[17]{};
        (void)snprintf(stableId, sizeof(stableId), "%016llx", (unsigned long long)stableHash);
        writer.key("stableId");
        writer.value_string(stableId);
        writer.end_object();
      }
 
      inline void runtime_schema_write_field(
          ser::ser_json& writer, const World& world, const ComponentCache& cache, const ComponentCacheItem& item,
          const RuntimeFieldDesc& field) {
        writer.begin_object();
        writer.key("name");
        const auto fieldName = item.field_name(field);
        writer.value_string(fieldName.data(), fieldName.size());
        writer.key("type");
        runtime_schema_write_type_ref(writer, cache, field.type);
        const auto* pFieldType = cache.find(field.type);
        writer.key("editable");
        writer.value_bool(
            (field.flags & (RuntimeFieldFlag_ReadOnly | RuntimeFieldFlag_Hidden)) == 0 && pFieldType != nullptr &&
            runtime_schema_type_editable(cache, *pFieldType));
        writer.key("offset");
        writer.value_int(field.offset);
        writer.key("count");
        writer.value_int(ComponentCacheItem::field_element_count(field));
        writer.key("semantic");
        runtime_schema_write_semantic_ref(writer, world, field.semantic);
        writer.key("jsonEncoding");
        writer.value_string(runtime_schema_json_encoding_name(field.jsonEncoding));
        writer.key("readOnly");
        writer.value_bool((field.flags & RuntimeFieldFlag_ReadOnly) != 0);
        writer.key("hidden");
        writer.value_bool((field.flags & RuntimeFieldFlag_Hidden) != 0);
        writer.key("multiline");
        writer.value_bool((field.flags & RuntimeFieldFlag_Multiline) != 0);
        const auto unit = item.field_unit(field);
        if (!unit.empty()) {
          writer.key("unit");
          writer.value_string(unit.data(), unit.size());
        }
        const auto fieldDescription = item.field_description(field);
        if (!fieldDescription.empty()) {
          writer.key("description");
          writer.value_string(fieldDescription.data(), fieldDescription.size());
        }
        if ((field.flags & RuntimeFieldFlag_HasMinimum) != 0) {
          writer.key("minimum");
          writer.value_float(field.minimum);
        }
        if ((field.flags & RuntimeFieldFlag_HasMaximum) != 0) {
          writer.key("maximum");
          writer.value_float(field.maximum);
        }
        if ((field.flags & RuntimeFieldFlag_HasStep) != 0) {
          writer.key("step");
          writer.value_float(field.step);
        }
        RuntimeJsonFieldLayout layout{};
        const bool derivedUtf8 = resolve_runtime_json_field_layout(&cache, field, layout) && layout.elemCount > 1 &&
                                 runtime_json_is_char8_type(layout.pType, layout.type);
        if (field.jsonEncoding == RuntimeJsonEncoding::Utf8String || derivedUtf8) {
          writer.key("encoding");
          writer.value_string("utf-8");
          writer.key("capacity");
          writer.value_int(layout.elemCount);
        }
        writer.end_object();
      }
 
      inline void runtime_schema_write_item(
          ser::ser_json& writer, const World& world, const ComponentCache& cache, const ComponentCacheItem& item,
          bool includeRuntimeEntity) {
        writer.begin_object();
        writer.key("symbol");
        const auto itemSymbol = item.symbol_name();
        writer.value_string(itemSymbol.data(), itemSymbol.size());
        writer.key("path");
        writer.value_string(item.path.empty() ? "" : item.path.data(), item.path.size());
        if (includeRuntimeEntity) {
          writer.key("entity");
          writer.begin_object();
          writer.key("id");
          writer.value_int(item.entity.id());
          writer.key("generation");
          writer.value_int(item.entity.gen());
          writer.end_object();
        }
        char stableId[17]{};
        (void)snprintf(stableId, sizeof(stableId), "%016llx", (unsigned long long)item.hashLookup.hash);
        writer.key("stableId");
        writer.value_string(stableId);
        writer.key("kind");
        writer.value_string(runtime_schema_kind_name(item.typeKind));
        const auto typeDescription = item.type_description();
        if (!typeDescription.empty()) {
          writer.key("description");
          writer.value_string(typeDescription.data(), typeDescription.size());
        }
        writer.key("semantic");
        runtime_schema_write_semantic_ref(writer, world, item.semantic);
        writer.key("jsonEncoding");
        writer.value_string(runtime_schema_json_encoding_name(item.jsonEncoding));
        writer.key("size");
        writer.value_int(item.comp.size());
        writer.key("alignment");
        writer.value_int(item.comp.alig());
        writer.key("storage");
        writer.value_string(runtime_schema_storage_name(item.comp.storage_type()));
        writer.key("layout");
        writer.value_string(item.comp.soa() == 0 ? "aos" : "soa");
        writer.key("editable");
        writer.value_bool(runtime_schema_type_editable(cache, item));
        if (item.jsonEncoding == RuntimeJsonEncoding::Utf8String) {
          writer.key("encoding");
          writer.value_string("utf-8");
        }
        if (item.underlyingType != EntityBad) {
          writer.key("underlyingType");
          runtime_schema_write_type_ref(writer, cache, item.underlyingType);
        }
        if (item.elementType != EntityBad) {
          writer.key("elementType");
          runtime_schema_write_type_ref(writer, cache, item.elementType);
          writer.key("elementCount");
          writer.value_int(item.elementCount);
        }
        if (item.opaqueAsType != EntityBad) {
          writer.key("opaqueAsType");
          runtime_schema_write_type_ref(writer, cache, item.opaqueAsType);
        }
        if (item.typeKind == RuntimeTypeKind::Vector) {
          writer.key("readable");
          writer.value_bool(
              item.sequenceAdapter != nullptr && item.sequenceAdapter->count != nullptr &&
              item.sequenceAdapter->element != nullptr);
          writer.key("resizable");
          writer.value_bool(item.sequenceAdapter != nullptr && item.sequenceAdapter->resize != nullptr);
        }
        if (item.typeKind == RuntimeTypeKind::Opaque) {
          writer.key("readable");
          writer.value_bool(item.opaqueAdapter != nullptr && item.opaqueAdapter->project != nullptr);
          writer.key("committable");
          writer.value_bool(item.opaqueAdapter != nullptr && item.opaqueAdapter->commit != nullptr);
        }
        if (item.comp.soa() != 0) {
          writer.key("soaElementSizes");
          writer.begin_array();
          GAIA_FOR(item.comp.soa()) writer.value_int(item.soaSizes[i]);
          writer.end_array();
        }
        writer.key("fields");
        writer.begin_array();
        GAIA_FOR(item.field_count()) runtime_schema_write_field(writer, world, cache, item, *item.field(i));
        writer.end_array();
        if (item.constant_count() != 0) {
          writer.key("constants");
          writer.begin_array();
          GAIA_FOR(item.constant_count()) {
            const auto& constant = *item.constant(i);
            writer.begin_object();
            writer.key("name");
            const auto constantName = item.constant_name(constant);
            writer.value_string(constantName.data(), constantName.size());
            writer.key("value");
            writer.value_int(constant.value);
            const auto constantDescription = item.constant_description(constant);
            if (!constantDescription.empty()) {
              writer.key("description");
              writer.value_string(constantDescription.data(), constantDescription.size());
            }
            writer.end_object();
          }
          writer.end_array();
        }
        writer.end_object();
      }
 
    } // namespace detail
 
    inline bool
    World::write_runtime_schema_json(ser::ser_json& writer, const char* schemaHash, bool includeRuntimeEntities) const {
      cnt::darray<const ComponentCacheItem*> items;
      items.reserve((uint32_t)m_compCache.m_compByEntityId.size());
      for (const auto& [entityId, pItem]: m_compCache.m_compByEntityId) {
        (void)entityId;
        items.push_back(pItem);
      }
      core::sort(items.begin(), items.end(), [](const ComponentCacheItem* a, const ComponentCacheItem* b) {
        const auto nameOrder = strcmp(a->symbol_name().data(), b->symbol_name().data());
        if (nameOrder != 0)
          return nameOrder < 0;
        const auto pathSize = a->path.size() < b->path.size() ? a->path.size() : b->path.size();
        const auto pathOrder = pathSize != 0 ? memcmp(a->path.data(), b->path.data(), pathSize) : 0;
        return pathOrder != 0 ? pathOrder < 0 : a->path.size() < b->path.size();
      });
      writer.clear();
      writer.begin_object();
      writer.key("format");
      writer.value_string("gaia.ecs.schema");
      writer.key("version");
      writer.value_int(2);
      if (schemaHash != nullptr) {
        writer.key("hash");
        writer.value_string(schemaHash);
      }
      writer.key("types");
      writer.begin_array();
      for (const auto* pItem: items)
        detail::runtime_schema_write_item(writer, *this, m_compCache, *pItem, includeRuntimeEntities);
      writer.end_array();
      writer.end_object();
      return true;
    }
 
    inline uint64_t World::runtime_schema_hash() const {
      ser::ser_json writer;
      (void)write_runtime_schema_json(writer, nullptr, false);
      const auto& canonical = writer.str();
      return core::calculate_hash64(canonical.data(), canonical.size());
    }
 
    inline bool World::save_runtime_schema_json(ser::ser_json& writer) const {
      char hash[17]{};
      (void)snprintf(hash, sizeof(hash), "%016llx", (unsigned long long)runtime_schema_hash());
      return write_runtime_schema_json(writer, hash, true);
    }
 
    inline ser::json_str World::save_runtime_schema_json() const {
      ser::ser_json writer;
      (void)save_runtime_schema_json(writer);
      return writer.str();
    }
 
  } // namespace ecs
} // namespace gaia
 
#endif