// This file is part of the lluz programming language and is licensed under MIT License; see LICENSE.txt for details
#include "lua.h"
#include "lualib.h"
#include "luacode.h"

#include "lluz/BuiltinDefinitions.h"
#include "lluz/ModuleResolver.h"
#include "lluz/TypeInfer.h"
#include "lluz/StringUtils.h"
#include "lluz/BytecodeBuilder.h"

#include "doctest.h"
#include "ScopedFlags.h"

#include <fstream>
#include <vector>
#include <math.h>

extern bool verbose;

static int lua_collectgarbage(lua_State* L)
{
    static const char* const opts[] = {"stop", "restart", "collect", "count", "isrunning", "step", "setgoal", "setstepmul", "setstepsize", nullptr};
    static const int optsnum[] = {
        LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT, LUA_GCCOUNT, LUA_GCISRUNNING, LUA_GCSTEP, LUA_GCSETGOAL, LUA_GCSETSTEPMUL, LUA_GCSETSTEPSIZE};

    int o = luaL_checkoption(L, 1, "collect", opts);
    int ex = luaL_optinteger(L, 2, 0);
    int res = lua_gc(L, optsnum[o], ex);
    switch (optsnum[o])
    {
    case LUA_GCSTEP:
    case LUA_GCISRUNNING:
    {
        lua_pushboolean(L, res);
        return 1;
    }
    default:
    {
        lua_pushnumber(L, res);
        return 1;
    }
    }
}

static int lua_loadstring(lua_State* L)
{
    size_t l = 0;
    const char* s = luaL_checklstring(L, 1, &l);
    const char* chunkname = luaL_optstring(L, 2, s);

    lua_setsafeenv(L, LUA_ENVIRONINDEX, false);

    size_t bytecodeSize = 0;
    char* bytecode = lluz_compile(s, l, nullptr, &bytecodeSize);
    int result = lluz_load(L, chunkname, bytecode, bytecodeSize, 0);
    free(bytecode);

    if (result == 0)
        return 1;

    lua_pushnil(L);
    lua_insert(L, -2); /* put before error message */
    return 2;          /* return nil plus error message */
}

static int lua_vector(lua_State* L)
{
    double x = luaL_checknumber(L, 1);
    double y = luaL_checknumber(L, 2);
    double z = luaL_checknumber(L, 3);

#if LUA_VECTOR_SIZE == 4
    double w = luaL_optnumber(L, 4, 0.0);
    lua_pushvector(L, float(x), float(y), float(z), float(w));
#else
    lua_pushvector(L, float(x), float(y), float(z));
#endif
    return 1;
}

static int lua_vector_dot(lua_State* L)
{
    const float* a = luaL_checkvector(L, 1);
    const float* b = luaL_checkvector(L, 2);

    lua_pushnumber(L, a[0] * b[0] + a[1] * b[1] + a[2] * b[2]);
    return 1;
}

static int lua_vector_index(lua_State* L)
{
    const float* v = luaL_checkvector(L, 1);
    const char* name = luaL_checkstring(L, 2);

    if (strcmp(name, "Magnitude") == 0)
    {
        lua_pushnumber(L, sqrtf(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]));
        return 1;
    }

    if (strcmp(name, "Dot") == 0)
    {
        lua_pushcfunction(L, lua_vector_dot, XorStr("Dot"));
        return 1;
    }

    luaL_error(L, XorStr("%s is not a valid member of vector"), name);
}

static int lua_vector_namecall(lua_State* L)
{
    if (const char* str = lua_namecallatom(L, nullptr))
    {
        if (strcmp(str, "Dot") == 0)
            return lua_vector_dot(L);
    }

    luaL_error(L, XorStr("%s is not a valid method of vector"), luaL_checkstring(L, 1));
}

int lua_silence(lua_State* L)
{
    return 0;
}

using StateRef = std::unique_ptr<lua_State, void (*)(lua_State*)>;

static StateRef runConformance(const char* name, void (*setup)(lua_State* L) = nullptr, void (*yield)(lua_State* L) = nullptr,
    lua_State* initialLuaState = nullptr, lua_CompileOptions* copts = nullptr)
{
    std::string path = __FILE__;
    path.erase(path.find_last_of("\\/"));
    path += "/conformance/";
    path += name;

    std::fstream stream(path, std::ios::in | std::ios::binary);
    REQUIRE(stream);

    std::string source(std::istreambuf_iterator<char>(stream), {});

    stream.close();

    if (!initialLuaState)
        initialLuaState = luaL_newstate();
    StateRef globalState(initialLuaState, lua_close);
    lua_State* L = globalState.get();

    luaL_openlibs(L);

    // Register a few global functions for conformance tests
    std::vector<luaL_Reg> funcs = {
        {"collectgarbage", lua_collectgarbage},
        {"loadstring", lua_loadstring},
    };

    if (!verbose)
    {
        funcs.push_back({"print", lua_silence});
    }

    // "null" terminate the list of functions to register
    funcs.push_back({nullptr, nullptr});

    lua_pushvalue(L, LUA_GLOBALSINDEX);
    luaL_register(L, nullptr, funcs.data());
    lua_pop(L, 1);

    // In some configurations we have a larger C stack consumption which trips some conformance tests
#if defined(lluz_ENABLE_ASAN) || defined(_NOOPT) || defined(_DEBUG)
    lua_pushboolean(L, true);
    lua_setglobal(L, XorStr("limitedstack"));
#endif

    // Extra test-specific setup
    if (setup)
        setup(L);

    // Protect core libraries and metatables from modification
    luaL_sandbox(L);

    // Create a new writable global table for current thread
    luaL_sandboxthread(L);

    // Lua conformance tests treat _G synonymously with getfenv(); for now cater to them
    lua_pushvalue(L, LUA_GLOBALSINDEX);
    lua_pushvalue(L, LUA_GLOBALSINDEX);
    lua_setfield(L, -1, XorStr("_G"));

    std::string chunkname = "=" + std::string(name);

    size_t bytecodeSize = 0;
    char* bytecode = lluz_compile(source.data(), source.size(), copts, &bytecodeSize);
    int result = lluz_load(L, chunkname.c_str(), bytecode, bytecodeSize, 0);
    free(bytecode);

    int status = (result == 0) ? lua_resume(L, nullptr, 0) : LUA_ERRSYNTAX;

    while (yield && (status == LUA_YIELD || status == LUA_BREAK))
    {
        yield(L);
        status = lua_resume(L, nullptr, 0);
    }

    extern void luaC_validate(lua_State * L); // internal function, declared in lgc.h - not exposed via lua.h
    luaC_validate(L);

    if (status == 0)
    {
        REQUIRE(lua_isstring(L, -1));
        CHECK(std::string(lua_tostring(L, -1)) == XorStr("OK"));
    }
    else
    {
        std::string error = (status == LUA_YIELD) ? "thread yielded unexpectedly" : lua_tostring(L, -1);
        error += "\nstacktrace:\n";
        error += lua_debugtrace(L);

        FAIL(error);
    }

    return globalState;
}

TEST_SUITE_BEGIN(XorStr("Conformance"));

TEST_CASE("Assert")
{
    runConformance(XorStr("assert.lua"));
}

TEST_CASE("Basic")
{
    ScopedFastFlag sff(XorStr("LluLenTM"), true);

    runConformance(XorStr("basic.lua"));
}

TEST_CASE("Math")
{
    runConformance(XorStr("math.lua"));
}

TEST_CASE("Table")
{
    runConformance("nextvar.lua", [](lua_State* L) {
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                unsigned v = luaL_checkunsigned(L, 1);
                lua_pushlightuserdata(L, reinterpret_cast<void*>(uintptr_t(v)));
                return 1;
            },
            XorStr("makelud"));
        lua_setglobal(L, XorStr("makelud"));
    });
}

TEST_CASE("PatternMatch")
{
    runConformance(XorStr("pm.lua"));
}

TEST_CASE("Sort")
{
    runConformance(XorStr("sort.lua"));
}

TEST_CASE("Move")
{
    runConformance(XorStr("move.lua"));
}

TEST_CASE("Clear")
{
    runConformance(XorStr("clear.lua"));
}

TEST_CASE("Strings")
{
    runConformance(XorStr("strings.lua"));
}

TEST_CASE("VarArg")
{
    runConformance(XorStr("vararg.lua"));
}

TEST_CASE("Locals")
{
    runConformance(XorStr("locals.lua"));
}

TEST_CASE("Literals")
{
    runConformance(XorStr("literals.lua"));
}

TEST_CASE("Errors")
{
    runConformance(XorStr("errors.lua"));
}

TEST_CASE("Events")
{
    ScopedFastFlag sff("LluLenTM", true);

    runConformance(XorStr("events.lua"));
}

TEST_CASE("Constructs")
{
    runConformance(XorStr("constructs.lua"));
}

TEST_CASE("Closure")
{
    runConformance(XorStr("closure.lua"));
}

TEST_CASE("Calls")
{
    runConformance(XorStr("calls.lua"));
}

TEST_CASE("Attrib")
{
    runConformance(XorStr("attrib.lua"));
}

TEST_CASE("GC")
{
    runConformance(XorStr("gc.lua"));
}

TEST_CASE("Bitwise")
{
    runConformance(XorStr("bitwise.lua"));
}

TEST_CASE("UTF8")
{
    runConformance(XorStr("utf8.lua"));
}

TEST_CASE("Coroutine")
{
    runConformance(XorStr("coroutine.lua"));
}

static int cxxthrow(lua_State* L)
{
#if LUA_USE_LONGJMP
    luaL_error(L, XorStr("oops"));
#else
    throw std::runtime_error(XorStr("oops"));
#endif
}

TEST_CASE("PCall")
{
    runConformance("pcall.lua", [](lua_State* L) {
        lua_pushcfunction(L, cxxthrow, XorStr("cxxthrow"));
        lua_setglobal(L, XorStr("cxxthrow"));

        lua_pushcfunction(
            L,
            [](lua_State* L) -> int {
                lua_State* co = lua_tothread(L, 1);
                lua_xmove(L, co, 1);
                lua_resumeerror(co, L);
                return 0;
            },
            XorStr("resumeerror"));
        lua_setglobal(L, XorStr("resumeerror"));
    });
}

TEST_CASE("Pack")
{
    runConformance(XorStr("tpack.lua"));
}

TEST_CASE("Vector")
{
    lua_CompileOptions copts = {};
    copts.optimizationLevel = 1;
    copts.debugLevel = 1;
    copts.vectorCtor = "vector";

    runConformance(
        "vector.lua",
        [](lua_State* L) {
            lua_pushcfunction(L, lua_vector, XorStr("vector"));
            lua_setglobal(L, XorStr("vector"));

#if LUA_VECTOR_SIZE == 4
            lua_pushvector(L, 0.0f, 0.0f, 0.0f, 0.0f);
#else
            lua_pushvector(L, 0.0f, 0.0f, 0.0f);
#endif
            luaL_newmetatable(L, XorStr("vector"));

            lua_pushstring(L, XorStr("__index"));
            lua_pushcfunction(L, lua_vector_index, nullptr);
            lua_settable(L, -3);

            lua_pushstring(L, XorStr("__namecall"));
            lua_pushcfunction(L, lua_vector_namecall, nullptr);
            lua_settable(L, -3);

            lua_setreadonly(L, -1, true);
            lua_setmetatable(L, -2);
            lua_pop(L, 1);
        },
        nullptr, nullptr, &copts);
}

static void populateRTTI(lua_State* L, lluz::TypeId type)
{
    if (auto p = lluz::get<lluz::PrimitiveTypeVar>(type))
    {
        switch (p->type)
        {
        case lluz::PrimitiveTypeVar::Boolean:
            lua_pushstring(L, XorStr("boolean"));
            break;

        case lluz::PrimitiveTypeVar::NilType:
            lua_pushstring(L, XorStr("nil"));
            break;

        case lluz::PrimitiveTypeVar::Number:
            lua_pushstring(L, XorStr("number"));
            break;

        case lluz::PrimitiveTypeVar::String:
            lua_pushstring(L, XorStr("string"));
            break;

        case lluz::PrimitiveTypeVar::Thread:
            lua_pushstring(L, XorStr("thread"));
            break;

        default:
            lluz_ASSERT(!XorStr("Unknown primitive type"));
        }
    }
    else if (auto t = lluz::get<lluz::TableTypeVar>(type))
    {
        lua_newtable(L);

        for (const auto& [name, prop] : t->props)
        {
            populateRTTI(L, prop.type);
            lua_setfield(L, -2, name.c_str());
        }
    }
    else if (lluz::get<lluz::FunctionTypeVar>(type))
    {
        lua_pushstring(L, XorStr("function"));
    }
    else if (lluz::get<lluz::AnyTypeVar>(type))
    {
        lua_pushstring(L, XorStr("any"));
    }
    else if (auto i = lluz::get<lluz::IntersectionTypeVar>(type))
    {
        for (const auto& part : i->parts)
            lluz_ASSERT(lluz::get<lluz::FunctionTypeVar>(part));

        lua_pushstring(L, XorStr("function"));
    }
    else
    {
        lluz_ASSERT(!XorStr("Unknown type"));
    }
}

TEST_CASE("Types")
{
    ScopedFastFlag sff("lluzCheckLenMT", true);

    runConformance("types.lua", [](lua_State* L) {
        lluz::NullModuleResolver moduleResolver;
        lluz::InternalErrorReporter iceHandler;
        lluz::TypeChecker env(&moduleResolver, &iceHandler);

        lluz::registerBuiltinTypes(env);
        lluz::freeze(env.globalTypes);

        lua_newtable(L);

        for (const auto& [name, binding] : env.globalScope->bindings)
        {
            populateRTTI(L, binding.typeId);
            lua_setfield(L, -2, toString(name).c_str());
        }

        lua_setglobal(L, XorStr("RTTI"));
    });
}

TEST_CASE("DateTime")
{
    runConformance(XorStr("datetime.lua"));
}

TEST_CASE("Debug")
{
    runConformance(XorStr("debug.lua"));
}

TEST_CASE("Debugger")
{
    static int breakhits = 0;
    static lua_State* interruptedthread = nullptr;

    breakhits = 0;
    interruptedthread = nullptr;

    lua_CompileOptions copts = {};
    copts.optimizationLevel = 1;
    copts.debugLevel = 2;

    runConformance(
        "debugger.lua",
        [](lua_State* L) {
            lua_Callbacks* cb = lua_callbacks(L);

            // for breakpoints to work we should make sure debugbreak is installed
            cb->debugbreak = [](lua_State* L, lua_Debug* ar) {
                breakhits++;

                // make sure we can trace the stack for every breakpoint we hit
                lua_debugtrace(L);

                // for every breakpoint, we break on the first invocation and continue on second
                // this allows us to easily step off breakpoints
                // (real implementaiton may require singlestepping)
                if (breakhits % 2 == 1)
                    lua_break(L);
            };

            // for resuming off a breakpoint inside a coroutine we need to resume the interrupted coroutine
            cb->debuginterrupt = [](lua_State* L, lua_Debug* ar) {
                CHECK(interruptedthread == nullptr);
                CHECK(ar->userdata); // userdata contains the interrupted thread

                interruptedthread = static_cast<lua_State*>(ar->userdata);
            };

            // add breakpoint() function
            lua_pushcfunction(
                L,
                [](lua_State* L) -> int {
                    int line = luaL_checkinteger(L, 1);
                    bool enabled = luaL_optboolean(L, 2, true);

                    lua_Debug ar = {};
                    lua_getinfo(L, 1, "f", &ar);

                    lua_breakpoint(L, -1, line, enabled);
                    return 0;
                },
                XorStr("breakpoint"));
            lua_setglobal(L, XorStr("breakpoint"));
        },
        [](lua_State* L) {
            CHECK(breakhits % 2 == 1);

            lua_checkstack(L, LUA_MINSTACK);

            if (breakhits == 1)
            {
                // test lua_getargument
                int a = lua_getargument(L, 0, 1);
                REQUIRE(a);
                CHECK(lua_tointeger(L, -1) == 50);
                lua_pop(L, 1);

                int v = lua_getargument(L, 0, 2);
                REQUIRE(v);
                CHECK(lua_tointeger(L, -1) == 42);
                lua_pop(L, 1);

                // test lua_getlocal
                const char* l = lua_getlocal(L, 0, 1);
                REQUIRE(l);
                CHECK(strcmp(l, "b") == 0);
                CHECK(lua_tointeger(L, -1) == 50);
                lua_pop(L, 1);

                // test lua_getupvalue
                lua_Debug ar = {};
                lua_getinfo(L, 0, "f", &ar);

                const char* u = lua_getupvalue(L, -1, 1);
                REQUIRE(u);
                CHECK(strcmp(u, "a") == 0);
                CHECK(lua_tointeger(L, -1) == 5);
                lua_pop(L, 2);
            }
            else if (breakhits == 3)
            {
                // validate assignment via lua_getlocal
                const char* l = lua_getlocal(L, 0, 1);
                REQUIRE(l);
                CHECK(strcmp(l, "a") == 0);
                CHECK(lua_tointeger(L, -1) == 6);
                lua_pop(L, 1);
            }
            else if (breakhits == 5)
            {
                // validate assignment via lua_getlocal
                const char* l = lua_getlocal(L, 1, 1);
                REQUIRE(l);
                CHECK(strcmp(l, "a") == 0);
                CHECK(lua_tointeger(L, -1) == 7);
                lua_pop(L, 1);
            }
            else if (breakhits == 7)
            {
                // validate assignment via lua_getlocal
                const char* l = lua_getlocal(L, 1, 1);
                REQUIRE(l);
                CHECK(strcmp(l, "a") == 0);
                CHECK(lua_tointeger(L, -1) == 8);
                lua_pop(L, 1);
            }
            else if (breakhits == 9)
            {
                // validate assignment via lua_getlocal
                const char* l = lua_getlocal(L, 1, 1);
                REQUIRE(l);
                CHECK(strcmp(l, "a") == 0);
                CHECK(lua_tointeger(L, -1) == 9);
                lua_pop(L, 1);
            }

            if (interruptedthread)
            {
                lua_resume(interruptedthread, nullptr, 0);
                interruptedthread = nullptr;
            }
        },
        nullptr, &copts);

    CHECK(breakhits == 10); // 2 hits per breakpoint
}

TEST_CASE("SameHash")
{
    extern unsigned int luaS_hash(const char* str, size_t len); // internal function, declared in lstring.h - not exposed via lua.h

    // To keep VM and compiler separate, we duplicate the hash function definition
    // This test validates that the hash function in question returns the same results on basic inputs
    // If this is violated, some code may regress in performance due to hash slot misprediction in inline caches
    CHECK(luaS_hash("", 0) == lluz::BytecodeBuilder::getStringHash({"", 0}));
    CHECK(luaS_hash("lua", 3) == lluz::BytecodeBuilder::getStringHash({"lua", 3}));
    CHECK(luaS_hash("lluz", 4) == lluz::BytecodeBuilder::getStringHash({"lluz", 4}));
    CHECK(luaS_hash("lluzbytecode", 12) == lluz::BytecodeBuilder::getStringHash({"lluzbytecode", 12}));
    CHECK(luaS_hash("lluzbytecodehash", 16) == lluz::BytecodeBuilder::getStringHash({"lluzbytecodehash", 16}));

    // Also hash should work on unaligned source data even when hashing long strings
    char buf[128] = {};
    CHECK(luaS_hash(buf + 1, 120) == luaS_hash(buf + 2, 120));
}

TEST_CASE("Reference")
{
    static int dtorhits = 0;

    dtorhits = 0;

    StateRef globalState(luaL_newstate(), lua_close);
    lua_State* L = globalState.get();

    // note, we push two userdata objects but only pin one of them (the first one)
    lua_newuserdatadtor(L, 0, [](void*) {
        dtorhits++;
    });
    lua_newuserdatadtor(L, 0, [](void*) {
        dtorhits++;
    });

    lua_gc(L, LUA_GCCOLLECT, 0);
    CHECK(dtorhits == 0);

    int ref = lua_ref(L, -2);
    lua_pop(L, 2);

    lua_gc(L, LUA_GCCOLLECT, 0);
    CHECK(dtorhits == 1);

    lua_getref(L, ref);
    CHECK(lua_isuserdata(L, -1));
    lua_pop(L, 1);

    lua_gc(L, LUA_GCCOLLECT, 0);
    CHECK(dtorhits == 1);

    lua_unref(L, ref);

    lua_gc(L, LUA_GCCOLLECT, 0);
    CHECK(dtorhits == 2);
}

TEST_CASE("ApiTables")
{
    StateRef globalState(luaL_newstate(), lua_close);
    lua_State* L = globalState.get();

    lua_newtable(L);
    lua_pushnumber(L, 123.0);
    lua_setfield(L, -2, XorStr("key"));
    lua_pushstring(L, XorStr("test"));
    lua_rawseti(L, -2, 5);

    // lua_gettable
    lua_pushstring(L, XorStr("key"));
    CHECK(lua_gettable(L, -2) == LUA_TNUMBER);
    CHECK(lua_tonumber(L, -1) == 123.0);
    lua_pop(L, 1);

    // lua_getfield
    CHECK(lua_getfield(L, -1, "key") == LUA_TNUMBER);
    CHECK(lua_tonumber(L, -1) == 123.0);
    lua_pop(L, 1);

    // lua_rawgetfield
    CHECK(lua_rawgetfield(L, -1, "key") == LUA_TNUMBER);
    CHECK(lua_tonumber(L, -1) == 123.0);
    lua_pop(L, 1);

    // lua_rawget
    lua_pushstring(L, XorStr("key"));
    CHECK(lua_rawget(L, -2) == LUA_TNUMBER);
    CHECK(lua_tonumber(L, -1) == 123.0);
    lua_pop(L, 1);

    // lua_rawgeti
    CHECK(lua_rawgeti(L, -1, 5) == LUA_TSTRING);
    CHECK(strcmp(lua_tostring(L, -1), "test") == 0);
    lua_pop(L, 1);

    lua_pop(L, 1);
}

TEST_CASE("ApiCalls")
{
    StateRef globalState = runConformance(XorStr("apicalls.lua"));
    lua_State* L = globalState.get();

    // lua_call
    {
        lua_getfield(L, LUA_GLOBALSINDEX, XorStr("add"));
        lua_pushnumber(L, 40);
        lua_pushnumber(L, 2);
        lua_call(L, 2, 1);
        CHECK(lua_isnumber(L, -1));
        CHECK(lua_tonumber(L, -1) == 42);
        lua_pop(L, 1);
    }

    // lua_pcall
    {
        lua_getfield(L, LUA_GLOBALSINDEX, XorStr("add"));
        lua_pushnumber(L, 40);
        lua_pushnumber(L, 2);
        lua_pcall(L, 2, 1, 0);
        CHECK(lua_isnumber(L, -1));
        CHECK(lua_tonumber(L, -1) == 42);
        lua_pop(L, 1);
    }

    // lua_equal with a sleeping thread wake up
    {
        lua_State* L2 = lua_newthread(L);

        lua_getfield(L2, LUA_GLOBALSINDEX, XorStr("create_with_tm"));
        lua_pushnumber(L2, 42);
        lua_pcall(L2, 1, 1, 0);

        lua_getfield(L2, LUA_GLOBALSINDEX, XorStr("create_with_tm"));
        lua_pushnumber(L2, 42);
        lua_pcall(L2, 1, 1, 0);

        // Reset GC
        lua_gc(L2, LUA_GCCOLLECT, 0);

        // Try to mark 'L2' as sleeping
        // Can't control GC precisely, even in tests
        lua_gc(L2, LUA_GCSTEP, 8);

        CHECK(lua_equal(L2, -1, -2) == 1);
        lua_pop(L2, 2);
    }

    // lua_clonefunction + fenv
    {
        lua_getfield(L, LUA_GLOBALSINDEX, XorStr("getpi"));
        lua_call(L, 0, 1);
        CHECK(lua_tonumber(L, -1) == 3.1415926);
        lua_pop(L, 1);

        lua_getfield(L, LUA_GLOBALSINDEX, XorStr("getpi"));

        // clone & override env
        lua_clonefunction(L, -1);
        lua_newtable(L);
        lua_pushnumber(L, 42);
        lua_setfield(L, -2, XorStr("pi"));
        lua_setfenv(L, -2);

        lua_call(L, 0, 1);
        CHECK(lua_tonumber(L, -1) == 42);
        lua_pop(L, 1);

        // this one calls original function again
        lua_call(L, 0, 1);
        CHECK(lua_tonumber(L, -1) == 3.1415926);
        lua_pop(L, 1);
    }

    // lua_clonefunction + upvalues
    {
        lua_getfield(L, LUA_GLOBALSINDEX, XorStr("incuv"));
        lua_call(L, 0, 1);
        CHECK(lua_tonumber(L, -1) == 1);
        lua_pop(L, 1);

        lua_getfield(L, LUA_GLOBALSINDEX, XorStr("incuv"));
        // two clones
        lua_clonefunction(L, -1);
        lua_clonefunction(L, -2);

        lua_call(L, 0, 1);
        CHECK(lua_tonumber(L, -1) == 2);
        lua_pop(L, 1);

        lua_call(L, 0, 1);
        CHECK(lua_tonumber(L, -1) == 3);
        lua_pop(L, 1);

        // this one calls original function again
        lua_call(L, 0, 1);
        CHECK(lua_tonumber(L, -1) == 4);
        lua_pop(L, 1);
    }
}

static bool endsWith(const std::string& str, const std::string& suffix)
{
    if (suffix.length() > str.length())
        return false;

    return suffix == std::string_view(str.c_str() + str.length() - suffix.length(), suffix.length());
}

#if !LUA_USE_LONGJMP
TEST_CASE("ExceptionObject")
{
    struct ExceptionResult
    {
        bool exceptionGenerated;
        std::string description;
    };

    auto captureException = [](lua_State* L, const char* functionToRun) {
        try
        {
            lua_State* threadState = lua_newthread(L);
            lua_getfield(threadState, LUA_GLOBALSINDEX, functionToRun);
            CHECK(lua_isLfunction(threadState, -1));
            lua_call(threadState, 0, 0);
        }
        catch (std::exception& e)
        {
            CHECK(e.what() != nullptr);
            return ExceptionResult{true, e.what()};
        }
        return ExceptionResult{false, XorStr("")};
    };

    auto reallocFunc = [](void* /*ud*/, void* ptr, size_t /*osize*/, size_t nsize) -> void* {
        if (nsize == 0)
        {
            free(ptr);
            return nullptr;
        }
        else if (nsize > 512 * 1024)
        {
            // For testing purposes return null for large allocations
            // so we can generate exceptions related to memory allocation
            // failures.
            return nullptr;
        }
        else
        {
            return realloc(ptr, nsize);
        }
    };

    StateRef globalState = runConformance("exceptions.lua", nullptr, nullptr, lua_newstate(reallocFunc, nullptr));
    lua_State* L = globalState.get();

    {
        ExceptionResult result = captureException(L, XorStr("infinite_recursion_error"));
        CHECK(result.exceptionGenerated);
    }

    {
        ExceptionResult result = captureException(L, XorStr("empty_function"));
        CHECK_FALSE(result.exceptionGenerated);
    }

    {
        ExceptionResult result = captureException(L, XorStr("pass_number_to_error"));
        CHECK(result.exceptionGenerated);
        CHECK(endsWith(result.description, "42"));
    }

    {
        ExceptionResult result = captureException(L, XorStr("pass_string_to_error"));
        CHECK(result.exceptionGenerated);
        CHECK(endsWith(result.description, "string argument"));
    }

    {
        ExceptionResult result = captureException(L, XorStr("pass_table_to_error"));
        CHECK(result.exceptionGenerated);
    }

    {
        ExceptionResult result = captureException(L, XorStr("large_allocation_error"));
        CHECK(result.exceptionGenerated);
    }
}
#endif

TEST_CASE("IfElseExpression")
{
    runConformance(XorStr("ifelseexpr.lua"));
}

TEST_CASE("TagMethodError")
{
    runConformance("tmerror.lua", [](lua_State* L) {
        auto* cb = lua_callbacks(L);

        cb->debugprotectederror = [](lua_State* L) {
            CHECK(lua_isyieldable(L));
        };
    });
}

TEST_CASE("Coverage")
{
    lua_CompileOptions copts = {};
    copts.optimizationLevel = 1;
    copts.debugLevel = 1;
    copts.coverageLevel = 2;

    runConformance(
        "coverage.lua",
        [](lua_State* L) {
            lua_pushcfunction(
                L,
                [](lua_State* L) -> int {
                    luaL_argexpected(L, lua_isLfunction(L, 1), 1, XorStr("function"));

                    lua_newtable(L);
                    lua_getcoverage(L, 1, L, [](void* context, const char* function, int linedefined, int depth, const int* hits, size_t size) {
                        lua_State* L = static_cast<lua_State*>(context);

                        lua_newtable(L);

                        lua_pushstring(L, function);
                        lua_setfield(L, -2, XorStr("name"));

                        lua_pushinteger(L, linedefined);
                        lua_setfield(L, -2, XorStr("linedefined"));

                        lua_pushinteger(L, depth);
                        lua_setfield(L, -2, XorStr("depth"));

                        for (size_t i = 0; i < size; ++i)
                            if (hits[i] != -1)
                            {
                                lua_pushinteger(L, hits[i]);
                                lua_rawseti(L, -2, int(i));
                            }

                        lua_rawseti(L, -2, lua_objlen(L, -2) + 1);
                    });

                    return 1;
                },
                XorStr("getcoverage"));
            lua_setglobal(L, XorStr("getcoverage"));
        },
        nullptr, nullptr, &copts);
}

TEST_CASE("StringConversion")
{
    runConformance(XorStr("strconv.lua"));
}

TEST_CASE("GCDump")
{
    // internal function, declared in lgc.h - not exposed via lua.h
    extern void luaC_dump(lua_State * L, void* file, const char* (*categoryName)(lua_State * L, uint8_t memcat));

    StateRef globalState(luaL_newstate(), lua_close);
    lua_State* L = globalState.get();

    // push various objects on stack to cover different paths
    lua_createtable(L, 1, 2);
    lua_pushstring(L, XorStr("value"));
    lua_setfield(L, -2, XorStr("key"));

    lua_pushinteger(L, 42);
    lua_rawseti(L, -2, 1000);

    lua_pushinteger(L, 42);
    lua_rawseti(L, -2, 1);

    lua_pushvalue(L, -1);
    lua_setmetatable(L, -2);

    lua_newuserdata(L, 42);
    lua_pushvalue(L, -2);
    lua_setmetatable(L, -2);

    lua_pushinteger(L, 1);
    lua_pushcclosure(L, lua_silence, "test", 1);

    lua_State* CL = lua_newthread(L);

    lua_pushstring(CL, XorStr("local x x = {} local function f() x[1] = math.abs(42) end function foo() coroutine.yield() end foo() return f"));
    lua_loadstring(CL);
    lua_resume(CL, nullptr, 0);

#ifdef _WIN32
    const char* path = "NUL";
#else
    const char* path = "/dev/null";
#endif

    FILE* f = fopen(path, XorStr("w"));
    REQUIRE(f);

    luaC_dump(L, f, nullptr);

    fclose(f);
}

TEST_CASE("Interrupt")
{
    static const int expectedhits[] = {
        2,
        9,
        5,
        5,
        5,
        5,
        5,
        5,
        5,
        5,
        5,
        5,
        5,
        6,
        11,
    };
    static int index;

    index = 0;

    runConformance(
        "interrupt.lua",
        [](lua_State* L) {
            auto* cb = lua_callbacks(L);

            // note: for simplicity here we setup the interrupt callback once
            // however, this carries a noticeable performance cost. in a real application,
            // it's advised to set interrupt callback on a timer from a different thread,
            // and set it back to nullptr once the interrupt triggered.
            cb->interrupt = [](lua_State* L, int gc) {
                if (gc >= 0)
                    return;

                CHECK(index < int(std::size(expectedhits)));

                lua_Debug ar = {};
                lua_getinfo(L, 0, "l", &ar);

                CHECK(ar.currentline == expectedhits[index]);

                index++;

                // check that we can yield inside an interrupt
                if (index == 5)
                    lua_yield(L, 0);
            };
        },
        [](lua_State* L) {
            CHECK(index == 5); // a single yield point
        });

    CHECK(index == int(std::size(expectedhits)));
}

TEST_CASE("UserdataApi")
{
    static int dtorhits = 0;

    dtorhits = 0;

    StateRef globalState(luaL_newstate(), lua_close);
    lua_State* L = globalState.get();

    // setup dtor for tag 42 (created later)
    lua_setuserdatadtor(L, 42, [](lua_State* l, void* data) {
        dtorhits += *(int*)data;
    });

    // light user data
    int lud;
    lua_pushlightuserdata(L, &lud);

    CHECK(lua_tolightuserdata(L, -1) == &lud);
    CHECK(lua_touserdata(L, -1) == &lud);
    CHECK(lua_topointer(L, -1) == &lud);

    // regular user data
    int* ud1 = (int*)lua_newuserdata(L, 4);
    *ud1 = 42;

    CHECK(lua_tolightuserdata(L, -1) == nullptr);
    CHECK(lua_touserdata(L, -1) == ud1);
    CHECK(lua_topointer(L, -1) == ud1);

    // tagged user data
    int* ud2 = (int*)lua_newuserdatatagged(L, 4, 42);
    *ud2 = -4;

    CHECK(lua_touserdatatagged(L, -1, 42) == ud2);
    CHECK(lua_touserdatatagged(L, -1, 41) == nullptr);
    CHECK(lua_userdatatag(L, -1) == 42);

    // user data with inline dtor
    void* ud3 = lua_newuserdatadtor(L, 4, [](void* data) {
        dtorhits += *(int*)data;
    });

    void* ud4 = lua_newuserdatadtor(L, 1, [](void* data) {
        dtorhits += *(char*)data;
    });

    *(int*)ud3 = 43;
    *(char*)ud4 = 3;

    globalState.reset();

    CHECK(dtorhits == 42);
}

TEST_CASE("Iter")
{
    runConformance(XorStr("iter.lua"));
}

const int kInt64Tag = 1;
static int gInt64MT = -1;

static int64_t getInt64(lua_State* L, int idx)
{
    if (void* p = lua_touserdatatagged(L, idx, kInt64Tag))
        return *static_cast<int64_t*>(p);

    if (lua_isnumber(L, idx))
        return lua_tointeger(L, idx);

    luaL_typeerror(L, 1, XorStr("int64"));
}

static void pushInt64(lua_State* L, int64_t value)
{
    void* p = lua_newuserdatatagged(L, sizeof(int64_t), kInt64Tag);

    lua_getref(L, gInt64MT);
    lua_setmetatable(L, -2);

    *static_cast<int64_t*>(p) = value;
}

TEST_CASE("Userdata")
{
    runConformance("userdata.lua", [](lua_State* L) {
        // create metatable with all the metamethods
        lua_newtable(L);
        gInt64MT = lua_ref(L, -1);

        // __index
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                void* p = lua_touserdatatagged(L, 1, kInt64Tag);
                if (!p)
                    luaL_typeerror(L, 1, XorStr("int64"));

                const char* name = luaL_checkstring(L, 2);

                if (strcmp(name, "value") == 0)
                {
                    lua_pushnumber(L, double(*static_cast<int64_t*>(p)));
                    return 1;
                }

                luaL_error(L, XorStr("unknown field %s"), name);
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__index"));

        // __newindex
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                void* p = lua_touserdatatagged(L, 1, kInt64Tag);
                if (!p)
                    luaL_typeerror(L, 1, XorStr("int64"));

                const char* name = luaL_checkstring(L, 2);

                if (strcmp(name, "value") == 0)
                {
                    double value = luaL_checknumber(L, 3);
                    *static_cast<int64_t*>(p) = int64_t(value);
                    return 0;
                }

                luaL_error(L, XorStr("unknown field %s"), name);
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__newindex"));

        // __eq
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                lua_pushboolean(L, getInt64(L, 1) == getInt64(L, 2));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__eq"));

        // __lt
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                lua_pushboolean(L, getInt64(L, 1) < getInt64(L, 2));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__lt"));

        // __le
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                lua_pushboolean(L, getInt64(L, 1) <= getInt64(L, 2));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__le"));

        // __add
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                pushInt64(L, getInt64(L, 1) + getInt64(L, 2));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__add"));

        // __sub
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                pushInt64(L, getInt64(L, 1) - getInt64(L, 2));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__sub"));

        // __mul
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                pushInt64(L, getInt64(L, 1) * getInt64(L, 2));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__mul"));

        // __div
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                // ideally we'd guard against 0 but it's a test so eh
                pushInt64(L, getInt64(L, 1) / getInt64(L, 2));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__div"));

        // __mod
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                // ideally we'd guard against 0 and INT64_MIN but it's a test so eh
                pushInt64(L, getInt64(L, 1) % getInt64(L, 2));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__mod"));

        // __pow
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                pushInt64(L, int64_t(pow(double(getInt64(L, 1)), double(getInt64(L, 2)))));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__pow"));

        // __unm
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                pushInt64(L, -getInt64(L, 1));
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__unm"));

        // __tostring
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                int64_t value = getInt64(L, 1);
                std::string str = std::to_string(value);
                lua_pushlstring(L, str.c_str(), str.length());
                return 1;
            },
            nullptr);
        lua_setfield(L, -2, XorStr("__tostring"));

        // ctor
        lua_pushcfunction(
            L,
            [](lua_State* L) {
                double v = luaL_checknumber(L, 1);
                pushInt64(L, int64_t(v));
                return 1;
            },
            XorStr("int64"));
        lua_setglobal(L, XorStr("int64"));
    });
}

TEST_SUITE_END();