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#ifndef SRC_TINT_CMD_FUZZ_IR_FUZZ_H_
#define SRC_TINT_CMD_FUZZ_IR_FUZZ_H_

#include <functional>
#include <string>
#include <tuple>
#include <utility>

#include "src/tint/utils/bytes/decoder.h"
#include "src/tint/utils/containers/slice.h"
#include "src/tint/utils/macros/static_init.h"

namespace tint::core::ir {
class Module;
}

namespace tint::fuzz::ir {

/// IRFuzzer describes a fuzzer function that takes a IR module as input
struct IRFuzzer {
    /// @param name the name of the fuzzer
    /// @param fn the fuzzer function
    /// @returns an IRFuzzer that invokes the function @p fn with the IR module, along with any
    /// additional arguments which are deserialized from the fuzzer input.
    template <typename... ARGS>
    static IRFuzzer Create(std::string_view name, void (*fn)(core::ir::Module&, ARGS...)) {
        if constexpr (sizeof...(ARGS) > 0) {
            auto fn_with_decode = [fn](core::ir::Module& module, Slice<const std::byte> data) {
                if (!data.data) {
                    return;
                }
                bytes::BufferReader reader{data};
                auto data_args = bytes::Decode<std::tuple<std::decay_t<ARGS>...>>(reader);
                if (data_args == Success) {
                    auto all_args =
                        std::tuple_cat(std::tuple<core::ir::Module&>{module}, data_args.Get());
                    std::apply(*fn, all_args);
                }
            };
            return IRFuzzer{name, std::move(fn_with_decode)};
        } else {
            return IRFuzzer{
                name,
                [fn](core::ir::Module& module, Slice<const std::byte>) { fn(module); },
            };
        }
    }

    /// Name of the fuzzer function
    std::string_view name;
    /// The fuzzer function
    std::function<void(core::ir::Module&, Slice<const std::byte> data)> fn;
};

/// Registers the fuzzer function with the IR fuzzer executable.
/// @param fuzzer the fuzzer
void Register(const IRFuzzer& fuzzer);

/// TINT_IR_MODULE_FUZZER registers the fuzzer function.
#define TINT_IR_MODULE_FUZZER(FUNCTION) \
    TINT_STATIC_INIT(                   \
        ::tint::fuzz::ir::Register(::tint::fuzz::ir::IRFuzzer::Create(#FUNCTION, FUNCTION)))

}  // namespace tint::fuzz::ir

#endif  // SRC_TINT_CMD_FUZZ_IR_FUZZ_H_
