/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#define USING_LOG_PREFIX  SQL_ENG

#include "ob_expr_get_package_var.h"
#include "lib/ob_name_def.h"
#include "share/object/ob_obj_cast.h"
#include "sql/session/ob_sql_session_info.h"
#include "sql/engine/ob_exec_context.h"
#include "sql/engine/expr/ob_expr_util.h"
#include "pl/ob_pl.h"
#include "pl/ob_pl_package.h"
#include "pl/ob_pl_package_manager.h"
#include "pl/ob_pl_package_state.h"
#include "observer/ob_server_struct.h"

namespace oceanbase
{
using namespace common;
using namespace pl;
namespace sql
{

int ObExprGetPackageVar::calc(ObObj &result,
                              uint64_t package_id,
                              int64_t spec_version,
                              int64_t body_version,
                              int64_t var_idx,
                              ObExecContext *exec_ctx,
                              ObSQLSessionInfo *session_info)
{
  int ret = OB_SUCCESS;
  ObMySQLProxy *sql_proxy = NULL;
  ObPL *pl_engine = NULL;
  ObPLPackageGuard *package_guard = NULL;
  share::schema::ObSchemaGetterGuard *schema_guard = NULL;
  if (OB_ISNULL(GCTX.schema_service_)) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("global schema service is null", K(ret));
  } else if (OB_ISNULL(exec_ctx)) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("exec ctx is null", K(ret));
  } else if (OB_ISNULL(session_info)) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("session info is null", K(ret));
  } else if (OB_ISNULL(sql_proxy = exec_ctx->get_sql_proxy())) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("sql proxy is null", K(ret));
  } else if (OB_ISNULL(pl_engine = session_info->get_pl_engine())) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("pl engine is null", K(ret));
  } else if (OB_ISNULL(package_guard = exec_ctx->get_package_guard())) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("package guard is null", K(ret));
  } else if (OB_NOT_NULL(exec_ctx->get_sql_ctx())
             && OB_NOT_NULL(exec_ctx->get_sql_ctx()->schema_guard_)) {
    schema_guard = exec_ctx->get_sql_ctx()->schema_guard_;
  }
  if (OB_SUCC(ret) && OB_ISNULL(schema_guard)) {
    schema_guard = &session_info->get_cached_schema_guard_info().get_schema_guard();
  }
  if (OB_SUCC(ret)) {
    ObPLResolveCtx resolve_ctx(exec_ctx->get_allocator(),
                               *session_info,
                               *schema_guard,
                               *package_guard,
                               *sql_proxy,
                               false);
    ObPLPackageManager &package_manager = pl_engine->get_package_manager();
    if (OB_FAIL(package_manager.get_package_var_val(
        resolve_ctx, *exec_ctx, package_id, spec_version, body_version, var_idx, result))) {
      LOG_WARN("get package var failed", K(ret));
    }
  } 
  return ret;
}

int ObExprGetPackageVar::calc_result_typeN(ObExprResType &type,
                                           ObExprResType *types_stack,
                                           int64_t param_num,
                                           ObExprTypeCtx &type_ctx) const
{
  int ret = OB_SUCCESS;
  ObExprResType *result_type = reinterpret_cast<ObExprResType *>(types_stack[2].get_param().get_int());
  type.set_type(result_type->get_type());
  if (ob_is_string_tc(result_type->get_type())
      || ob_is_raw_tc(result_type->get_type())) {
    type.set_length(result_type->get_length());
    type.set_length_semantics(result_type->get_length_semantics());
    type.set_collation_type(result_type->get_collation_type());
    type.set_collation_level(result_type->get_collation_level());
  } else if (ob_is_number_tc(result_type->get_type()) ||
             ob_is_interval_tc(result_type->get_type())) {
    type.set_precision(result_type->get_precision());
    type.set_scale(result_type->get_scale());
  } else if (ob_is_text_tc(result_type->get_type())
             || ob_is_lob_tc(result_type->get_type())) {
    type.set_length(result_type->get_length());
    type.set_collation_type(result_type->get_collation_type());
    type.set_collation_level(result_type->get_collation_level());
    type.set_scale(result_type->get_scale());
  }
  return ret;
}

int ObExprGetPackageVar::eval_get_package_var(const ObExpr &expr,
                                              ObEvalCtx &ctx,
                                              ObDatum &res)
{
  int ret = OB_SUCCESS;
  ObDatum *package_id = NULL;
  ObDatum *var_idx = NULL;
  ObDatum *result_type = NULL;
  ObDatum *spec_version = NULL;
  ObDatum *body_version = NULL;
  if (OB_FAIL(expr.eval_param_value(
      ctx, package_id, var_idx, result_type, spec_version, body_version))) {
    LOG_WARN("eval arg failed", K(ret));
  } else if (package_id->is_null()
             || var_idx->is_null()
             || result_type->is_null()
             || spec_version->is_null()
             || body_version->is_null()) {
    res.set_null();
  } else {
    ObObj res_obj;
    OZ(calc(res_obj,
            package_id->get_uint(),
            spec_version->get_int(),
            body_version->get_int(),
            var_idx->get_int(),
            &ctx.exec_ctx_,
            ctx.exec_ctx_.get_my_session()));
    if (OB_SUCC(ret)) {
      if (res_obj.is_string_type()) {
        ObString res_str;
        ObExprStrResAlloc res_alloc(expr, ctx);
        OZ(res_obj.get_string(res_str));
        OZ(ObExprUtil::deep_copy_str(res_str, res_str, res_alloc));
        OX(res.set_string(res_str));
      } else {
        OZ(res.from_obj(res_obj));
      }
    }
  }
  return ret;
}

int ObExprGetPackageVar::cg_expr(ObExprCGCtx &ctx,
                                 const ObRawExpr &raw_expr,
                                 ObExpr &rt_expr) const
{
  int ret = OB_SUCCESS;
  UNUSED(ctx);
  UNUSED(raw_expr);
  CK(5 == rt_expr.arg_cnt_);
  OX(rt_expr.eval_func_ = eval_get_package_var);
  return ret;
}
} //namespace sql
} //namespace oceanbase