// Copyright (c) Lysann Tranvouez.  All rights reserved.

#include <catch2/catch_test_macros.hpp>

#include <mach_detours.h>

#include "lib_function.h"
static int (*realLibFunction)() = libFunction;

static int libFunctionDetourCounter = 0;
static int libFunctionDetour()
{
    libFunctionDetourCounter++;
    return 94;
}

TEST_CASE( "Must start a transaction to attach", "[transaction]" )
{
    libFunctionCounter = 0;
    libFunctionDetourCounter = 0;

    CHECK( detour_attach(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == detour_err_wrong_thread );
    CHECK( libFunction() == 42 );
    CHECK( libFunctionCounter == 1 );
    CHECK( libFunctionDetourCounter == 0 );
}

TEST_CASE( "Must start a transaction to detach", "[transaction]" )
{
    libFunctionCounter = 0;
    libFunctionDetourCounter = 0;

    REQUIRE( detour_transaction_begin() == err_none );
    REQUIRE( detour_attach_and_commit(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );

    CHECK( detour_detach_and_commit(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == detour_err_wrong_thread );

    CHECK( libFunction() == 94 );
    CHECK( libFunctionCounter == 0 );
    CHECK( libFunctionDetourCounter == 1 );

    CHECK( detour_transaction_begin() == err_none );
    CHECK( detour_detach_and_commit(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );

    CHECK( libFunction() == 42 );
    CHECK( libFunctionCounter == 1 );
    CHECK( libFunctionDetourCounter == 1 );
}

TEST_CASE( "aborting transaction means no detour", "[transaction]" )
{
    libFunctionCounter = 0;
    libFunctionDetourCounter = 0;

    REQUIRE( detour_transaction_begin() == err_none );
    REQUIRE( detour_attach(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
    CHECK( detour_transaction_abort() == err_none );

    CHECK( realLibFunction == libFunction );
    CHECK( libFunctionCounter == 0 );
    CHECK( libFunctionDetourCounter == 0 );
    CHECK( libFunction() == 42 );
    CHECK( libFunctionCounter == 1 );
    CHECK( libFunctionDetourCounter == 0 );
}

TEST_CASE( "an error in a transaction means no detour", "[transaction]" )
{
    libFunctionCounter = 0;
    libFunctionDetourCounter = 0;

    REQUIRE( detour_transaction_begin() == err_none );
    REQUIRE( detour_attach(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == err_none );
    // cannot detach because trampoline is not yet in place
    CHECK( detour_detach(reinterpret_cast<detour_func_t*>(&realLibFunction), reinterpret_cast<detour_func_t>(libFunctionDetour)) == KERN_FAILURE );
    CHECK( detour_transaction_commit() == KERN_FAILURE );

    CHECK( realLibFunction == libFunction );
    CHECK( libFunctionCounter == 0 );
    CHECK( libFunctionDetourCounter == 0 );
    CHECK( libFunction() == 42 );
    CHECK( libFunctionCounter == 1 );
    CHECK( libFunctionDetourCounter == 0 );
}