// Copyright 2024 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package contextimpl

import (
	exprctx "github.com/pingcap/tidb/pkg/expression/context"
	"github.com/pingcap/tidb/pkg/parser/model"
	"github.com/pingcap/tidb/pkg/sessionctx"
	"github.com/pingcap/tidb/pkg/sessionctx/variable"
	"github.com/pingcap/tidb/pkg/table/context"
	"github.com/pingcap/tidb/pkg/util/tableutil"
	"github.com/pingcap/tipb/go-binlog"
)

var _ context.MutateContext = &TableContextImpl{}
var _ context.AllocatorContext = &TableContextImpl{}

// TableContextImpl is used to provide context for table operations.
type TableContextImpl struct {
	sessionctx.Context
	// mutateBuffers is a memory pool for table related memory allocation that aims to reuse memory
	// and saves allocation
	// The buffers are supposed to be used inside AddRecord/UpdateRecord/RemoveRecord.
	mutateBuffers *context.MutateBuffers
}

// NewTableContextImpl creates a new TableContextImpl.
func NewTableContextImpl(sctx sessionctx.Context) *TableContextImpl {
	return &TableContextImpl{
		Context:       sctx,
		mutateBuffers: context.NewMutateBuffers(sctx.GetSessionVars().GetWriteStmtBufs()),
	}
}

// TxnRecordTempTable record the temporary table to the current transaction.
// This method will be called when the temporary table is modified in the transaction.
func (ctx *TableContextImpl) TxnRecordTempTable(tbl *model.TableInfo) tableutil.TempTable {
	return ctx.vars().GetTemporaryTable(tbl)
}

// GetExprCtx returns the ExprContext
func (ctx *TableContextImpl) GetExprCtx() exprctx.ExprContext {
	return ctx.Context.GetExprCtx()
}

// InRestrictedSQL returns whether the current context is used in restricted SQL.
func (ctx *TableContextImpl) InRestrictedSQL() bool {
	return ctx.vars().StmtCtx.InRestrictedSQL
}

// BinlogEnabled returns whether the binlog is enabled.
func (ctx *TableContextImpl) BinlogEnabled() bool {
	return ctx.vars().BinlogClient != nil
}

// GetBinlogMutation returns a `binlog.TableMutation` object for a table.
func (ctx *TableContextImpl) GetBinlogMutation(tblID int64) *binlog.TableMutation {
	return ctx.Context.StmtGetMutation(tblID)
}

// GetRowEncodingConfig returns the RowEncodingConfig.
func (ctx *TableContextImpl) GetRowEncodingConfig() context.RowEncodingConfig {
	vars := ctx.vars()
	return context.RowEncodingConfig{
		IsRowLevelChecksumEnabled: vars.IsRowLevelChecksumEnabled(),
		RowEncoder:                &vars.RowEncoder,
	}
}

// GetMutateBuffers implements the MutateContext interface.
func (ctx *TableContextImpl) GetMutateBuffers() *context.MutateBuffers {
	return ctx.mutateBuffers
}

func (ctx *TableContextImpl) vars() *variable.SessionVars {
	return ctx.Context.GetSessionVars()
}