memgraph/src/query_engine/code_generator.hpp

#pragma once

#include "config/config.hpp"
#include "cypher/ast/ast.hpp"
#include "cypher/compiler.hpp"
#include "query_engine/exceptions/exceptions.hpp"
#include "template_engine/engine.hpp"
#include "traverser/cpp_traverser.hpp"
#include "utils/string/file.hpp"

// TODO:
//     * logger
#include <iostream>

using std::string;

class CodeGenerator
{
public:
    void generate_cpp(const std::string &query, const uint64_t stripped_hash,
                      const std::string &path)
    {
        // TODO: optimize initialize only once -> be careful that object has
        // a state
        // TODO: multithread test
        CppTraverser cpp_traverser;

        // get paths
        string template_path = CONFIG(config::TEMPLATE_CPU_CPP_PATH);
        string template_file = utils::read_file(template_path.c_str());

        // syntax tree generation
        try {
            tree = compiler.syntax_tree(query);
        } catch (const std::exception &e) {
            // TODO: extract more information
            throw QueryEngineException("Syntax tree generation error");
        }

        cpp_traverser.reset();

        // code generation
        try {
            tree.root->accept(cpp_traverser);
        } catch (const SemanticException &e) {
            throw e;
        } catch (const std::exception &e) {
            throw QueryEngineException("Code generation error");
        }

        // save the code
        string generated = template_engine.render(
            template_file, {{"class_name", "CodeCPU"},
                            {"stripped_hash", std::to_string(stripped_hash)},
                            {"query", query},
                            {"code", cpp_traverser.code}});

        // TODO: use logger, ifndef
        std::cout << generated << std::endl;

        utils::write_file(generated, path);
    }

private:
    template_engine::TemplateEngine template_engine;
    ast::Ast tree;
    cypher::Compiler compiler;
};