ReshadePluginsCore/libs/Unity/MonoLoader.hpp

#pragma once
#include <spdlog/spdlog.h>
#include <spdlog/sinks/basic_file_sink.h>

// Forward declarations Mono
struct MonoDomain;
struct MonoAssembly;
struct MonoImage;
struct MonoClass;
struct MonoMethod;
struct MonoMethodSignature;

// Typedefs pour les exports Mono
using mono_assembly_foreach_t = void(*)(void(*)(MonoAssembly*, void*), void*);
using mono_assembly_get_name_t = const void* (*)(MonoAssembly*);
using mono_assembly_name_get_name_t = const char* (*)(const void*);
using mono_class_get_methods_t = MonoMethod * (*)(MonoClass*, void**);
using mono_method_get_name_t = const char* (*)(MonoMethod*);
using mono_method_signature_t = MonoMethodSignature * (*)(MonoMethod*);
using mono_signature_get_param_count_t = uint32_t(*)(MonoMethodSignature*);

class MonoLoader {
public:
    MonoLoader() = default;
    ~MonoLoader() = default;

    /**
     * @brief Callback used during Mono assembly enumeration.
     *
     * This function is passed to `mono_assembly_foreach` and checks each loaded assembly
     * to find the one matching a specific name (provided via userData).
     * Can be used to initialize pointers to target assemblies.
     *
     * @param assembly Pointer to the current assembly.
     * @param userData User data passed to `mono_assembly_foreach`, typically a structure
     *                 containing the target name and a location to store the result.
     */
    bool Initialize(std::shared_ptr<spdlog::logger> log = nullptr, const char* monoName = "mono-2.0-bdwgc.dll");
    MonoDomain* GetDomain() const { return g_monoDomain; }

    /**
     * @brief Finds a Mono assembly by its name.
     *
     * This function iterates over all loaded assemblies in the Mono domain and
     * returns a pointer to the assembly matching the given name.
     *
     * @param name Name of the assembly to search for.
     * @return MonoAssembly* Pointer to the found assembly, or nullptr if not found.
     */
    MonoAssembly* FindAssembly(const std::string& name);

    /**
     * @brief Finds a class in a loaded assembly by namespace and name.
     * @param assemblyName Name of the assembly (ex: "UnityEngine.CoreModule").
     * @param namespaceName Namespace of the class (ex: "UnityEngine").
     * @param className Name of the class (ex: "Screen").
     * @return Pointer to the MonoClass, or nullptr if not found.
     */
    MonoClass* FindClass(const std::string& assemblyName, const std::string& namespaceName, const std::string& className);

    /**
     * @brief Finds a method in a MonoClass and compiles it.
     * @param monoClass The MonoClass to search in.
     * @param methodName The method name (ex: "get_width").
     * @param paramCount Number of parameters.
     * @return Compiled method address (uint8_t*), or nullptr if not found.
     */
    uint8_t* GetCompiledMethod(MonoClass* monoClass, const std::string& methodName, int paramCount);

    void DumpMethods(MonoClass* monoClass, std::shared_ptr<spdlog::logger> log = nullptr);

    // Exports
    mono_assembly_foreach_t mono_assembly_foreach = nullptr;
    mono_assembly_get_name_t mono_assembly_get_name = nullptr;
    mono_assembly_name_get_name_t mono_assembly_name_get_name = nullptr;
    MonoDomain* (*g_mono_get_root_domain)() = nullptr;
    void (*g_mono_thread_attach)(MonoDomain*) = nullptr;
    MonoAssembly* (*g_mono_domain_assembly_open)(MonoDomain*, const char*) = nullptr;
    MonoImage* (*g_mono_assembly_get_image)(MonoAssembly*) = nullptr;
    MonoClass* (*g_mono_class_from_name)(MonoImage*, const char*, const char*) = nullptr;
    MonoMethod* (*g_mono_class_get_method_from_name)(MonoClass*, const char*, int) = nullptr;
    void* (*g_mono_compile_method)(MonoMethod*) = nullptr;
    mono_class_get_methods_t mono_class_get_methods = nullptr;
    mono_method_get_name_t mono_method_get_name = nullptr;
    mono_method_signature_t mono_method_signature = nullptr;
    mono_signature_get_param_count_t mono_signature_get_param_count = nullptr;


private:
    MonoDomain* g_monoDomain = nullptr;
    std::shared_ptr<spdlog::logger> logger;

    /**
     * @brief Waits for the Mono module to be loaded in the process and returns its handle.
     *
     * This function loops every 200 ms until the "mono-2.0-bdwgc.dll" module
     * is present in the current process. Useful to ensure that Mono is initialized
     * before resolving its exports.
     *
     * @return HMODULE Handle of the Mono module, or nullptr if not found (practically never).
     */
    HMODULE WaitForMono(const char* monoName);

    /**
     * @brief Callback used during Mono assembly enumeration.
     *
     * This function is passed to `mono_assembly_foreach` and checks each loaded assembly
     * to find the one matching a specific name (provided via userData).
     * Can be used to initialize pointers to target assemblies.
     *
     * @param assembly Pointer to the current assembly.
     * @param userData User data passed to `mono_assembly_foreach`, typically a structure
     *                 containing the target name and a location to store the result.
     */
    static void FindAssemblyCallback(MonoAssembly* assembly, void* userData);
};