#include "commons/commons_luajit.h"

#include "commons/commons_base.h"

typedef struct lua_State lua_State;
typedef int (*lua_CFunction)(lua_State*);

typedef long long lua_Integer;

#define LUA_MULTRET (-1)
#define LUA_TNUMBER 3
#define LUA_TSTRING 4
#define LUA_GLOBALSINDEX (-10002)

#define LUAJIT_SYMBOLS(X)                                       \
    X(luaL_newstate, lua_State*, (void))                        \
    X(luaL_openlibs, void, (lua_State*))                        \
    X(lua_close, void, (lua_State*))                            \
    X(luaL_loadfile, int, (lua_State*, const char*))            \
    X(lua_pcall, int, (lua_State*, int, int, int))              \
    X(lua_tolstring, const char*, (lua_State*, int, size_t*))   \
    X(lua_tonumber, double, (lua_State*, int))                  \
    X(lua_tointeger, lua_Integer, (lua_State*, int))            \
    X(lua_pushnumber, void, (lua_State*, double))               \
    X(lua_pushstring, void, (lua_State*, const char*))          \
    X(lua_pushcclosure, void, (lua_State*, lua_CFunction, int)) \
    X(lua_setfield, void, (lua_State*, int, const char*))       \
    X(lua_createtable, void, (lua_State*, int, int))            \
    X(lua_gettop, int, (lua_State*))                            \
    X(lua_type, int, (lua_State*, int))

#define DECLARE_LUAJIT_SYMBOL(name, ret, args) \
    typedef ret(*name##_fn) args;              \
    static name##_fn p_##name;

LUAJIT_SYMBOLS(DECLARE_LUAJIT_SYMBOL)

static const char*
LuaString(lua_State* L, int index)
{
    const char* str = p_lua_tolstring(L, index, nullptr);
    if (str)
        return str;
    else
        return "";
}

#ifdef _WIN32

static HMODULE luaLib;

static void*
Lua_LoadSymbol(const char* name)
{
    void* p = (void*)GetProcAddress(luaLib, name);
    ASSERT(p, "missing symbol: %s", name);
    return p;
}

#else

static void* luaLib;

static void*
Lua_LoadSymbol(const char* name)
{
    void* p = dlsym(luaLib, name);
    ASSERT(p, "missing symbol: %s", name);
    return p;
}

#endif

static lua_State* L;

static void
Lua_Bootstrap()
{
#if defined(_WIN32)
    luaLib = LoadLibraryA("lua51.dll");
#else
    luaLib = dlopen("libluajit-5.1.so", RTLD_NOW | RTLD_LOCAL);
#endif

    ASSERT(luaLib);

#define X(name, ret, args) \
    p_##name = (name##_fn)Lua_LoadSymbol(#name);

    LUAJIT_SYMBOLS(X)

#undef X

    L = p_luaL_newstate();
    ASSERT(L);

    p_luaL_openlibs(L);
}

static lua_Integer
Lua_GetInteger(lua_State* state, int index)
{
    // ASSERT(p_lua_isinteger(state, index), "Lua argument is not an integer");
    return p_lua_tointeger(state, index);
}

static byteview
Lua_GetByteview(lua_State* state, int index)
{
    size_t len = 0;
    const char* str = p_lua_tolstring(state, index, &len);
    ASSERT(str, "Lua argument is not a string");
    return byteview { (uint8_t*)str, (uint64_t)len };
}

static void
Lua_BeginExport()
{
    p_lua_createtable(L, 0, 3);
}

static void
Lua_ExportFn(int (*fn)(lua_State*), const char* name)
{
    p_lua_pushcclosure(L, (lua_CFunction)fn, 0);
    p_lua_setfield(L, -2, name);
}

static void
Lua_EndExport(const char* name)
{
    p_lua_setfield(L, LUA_GLOBALSINDEX, name);
}

static void
Lua_ExecFile(const char* path)
{
    int err = p_luaL_loadfile(L, path);
    if (err) {
        ASSERT(false, "luaL_loadfile('%s') failed: %s", path, LuaString(L, -1));
    }

    err = p_lua_pcall(L, 0, LUA_MULTRET, 0);
    if (err) {
        ASSERT(false, "lua_pcall('%s') failed: %s", path, LuaString(L, -1));
    }
}