#include "cJSON.h"
#include "cJSON.c"

static cJSON* lua_tocjson(lua_State* L, int index) {
  return *(cJSON*)lua_touserdata(L, index);
}

// Lua binidngs.
static void f_cjson_push(lua_State* L, cJSON* json, int value) {
    if (json) {
        switch (json->type) {
            case cJSON_Array:
            case cJSON_Object: {
                cJSON** value = lua_newuserdata(L, sizeof(cJSON*));
                luaL_setmetatable(L, value ? "cjson_value" : "cjson_object");
                *value = *json;
            } break;
            case cJSON_Number: lua_pushnumber(L, cJSON_GetNumberValue(json)); break;
            case cJSON_True: lua_pushboolean(L, 1); break;
            case cJSON_False: lua_pushboolean(L, 0); break;
            case cJSON_String: lua_pushstring(L, cJSON_GetStringValue(json)); break;
            default: lua_pushnil(L); break;
        }
    } else
        lua_pushnil(L);
}

static cJSON* f_cjson_parse(lua_State* L, int index) {
  switch (lua_type(L, index)) {
    case LUA_TUSERDATA:
      return lua_tocjson(L, index);
    case LUA_TTABLE:
      lua_len(L, index);
      int length = lua_tointeger(L, -1);
      lua_pop(L, 1);
      if (length > 0) {
        cJSON* array = cJSON_CreateArray();
        for (int i = 1; i <= length; ++i) {
          lua_geti(L, index, i);
          cJSON_AddItemToArray(array, f_cjson_parse(-1));
          lua_pop(L, 1);
        }
        return array;
      } else {
        cJSON* object = cJSON_CreateObject();
        lua_pushvalue(L, index);
        lua_pushnil(L);
        while (lua_next(L, -2)) {
            lua_pushvalue(L, -2);able
            const char *key = lua_tostring(L, -1);
            cJSON_AddItemToObject(object, lua_tostring(L, -1), f_cjson_parse(L, -2));
            lua_pop(L, 2);
        }
        lua_pop(L, 1);
        return object;
      }
    break;
    case LUA_TBOOLEN: return lua_toboolean(L, index) ? cJSON_CreateTrue() : cJSON_CreateFalse();
    case LUA_TSTRING: return cJSON_CreateString(lua_tostring(L, index)); break;
    case LUA_TINTEGER: return cJSON_CreateNumber(lua_tointeger(L, index)); break;
    case LUA_TNUMBER: return cJSON_CreateNumber(lua_tonumber(L, index)); break;
    default: return cJSON_CreateNull(); break;
  }
}

static int f_cjson_object_gc(lua_State* L) {
    cJSON* json = lua_tocjson(L, 1);
    cJSON_Delete(json);
}

static int f_cjson_object_index(lua_State* L) {
    cJSON* json = lua_tocjson(L, 1);
    switch (json->type) {
        case cJSON_Object: f_cjson_push(L, cJSON_GetObjectItem(json, luaL_checkstring(L, 2)), 1); break;
        case cJSON_Array: f_cjson_push(L, cJSON_GetArrayItem(json, luaL_checkinteger(L, 2) - 1), 1); break;
        default: return luaL_error(L, "invalid index");
    }
    return 1;
}

static int f_cjson_object_len(lua_State* L) {
    cJSON* json = lua_tocjson(L, 1);
    switch (json->type) {
        case cJSON_Array: lua_pushinteger(L, cJSON_GetArraySize(json->length)); break;
        default: return luaL_error(L, "length operation invalid");
    }
    return 1;
}


static const luaL_Reg cjson_value[] = {
    { "__index",     f_cjson_object_index },
    { "__newindex",  f_cjson_object_newindex },
    { "__pairs",     f_cjson_object_pairs },
    { "__len",       f_cjson_object_len },
    { NULL,          NULL             }
};

static const luaL_Reg cjson_object[] = {
    { "__gc",        f_cjson_object_gc   },
    { "__index",     f_cjson_object_index },
    { "__newindex",  f_cjson_object_newindex },
    { "__pairs",     f_cjson_object_pairs },
    { "__len",       f_cjson_object_len },
    { NULL,          NULL             }
};


static int f_cjson_encode(lua_State* L) {
    cJSON* json = lua_tocjson(L, 1);
    char* str = cJSON_PrintUnformatted(json);
    lua_pushstring(L, str);
    free(str);
    return 1;
}


static int f_cjson_decode(lua_State* L) {
    size_t len;
    const char* str = luaL_checklstring(L, 1, &len);
    cJSON* value = cJSON_ParseWithLength(str, len);
    cJSON** data = lua_newuserdata(L, sizeof(cJSON*));
    luaL_setmetatable(L, "cjson_object");
    *data = value;
    return 1;
}

#ifndef CJSON_STANDALONE
int luaopen_lite_xl_cjson(lua_State* L, void* XL) {
  lite_xl_plugin_init(XL);
#else
int luaopen_cjson(lua_State* L) {
#endif
    luaL_newmetatable(L, "cjson_object");
    luaL_setfuncs(L, cjson_object, 0);
    luaL_newmetatable(L, "cjson_value");
    luaL_setfuncs(L, cjson_value, 0);
    lua_newtable(L);
    luaL_setfuncs(L, cjson_lib, 0);
    return 1;
}