// 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 resolve is used for semantic resolve of the AST tree.
// semantic resolve is mostly done by 'core.preprocessor', in tableListExtractor
// and updatableTableListResolver we also do some resolve for aliases.
package resolve

import (
	"github.com/pingcap/tidb/pkg/meta/model"
	"github.com/pingcap/tidb/pkg/parser/ast"
)

// TableNameW is a wrapper around ast.TableName to store more information.
type TableNameW struct {
	*ast.TableName
	DBInfo    *model.DBInfo
	TableInfo *model.TableInfo
}

// NodeW is a wrapper around ast.Node to store resolve context.
type NodeW struct {
	Node       ast.Node
	resolveCtx *Context
}

// NewNodeW creates a NodeW.
func NewNodeW(node ast.Node) *NodeW {
	return &NodeW{
		Node:       node,
		resolveCtx: NewContext(),
	}
}

// NewNodeWWithCtx creates a NodeW with the given Context.
func NewNodeWWithCtx(node ast.Node, resolveCtx *Context) *NodeW {
	return &NodeW{
		Node:       node,
		resolveCtx: resolveCtx,
	}
}

// CloneWithNewNode creates a new NodeW with the given ast.Node.
func (n *NodeW) CloneWithNewNode(newNode ast.Node) *NodeW {
	return &NodeW{
		Node:       newNode,
		resolveCtx: n.resolveCtx,
	}
}

// GetResolveContext returns the Context of the NodeW.
func (n *NodeW) GetResolveContext() *Context {
	return n.resolveCtx
}

// Context is used to store the context and result of resolving AST tree.
type Context struct {
	tableNames map[*ast.TableName]*TableNameW
}

// NewContext creates a Context.
func NewContext() *Context {
	return &Context{
		tableNames: make(map[*ast.TableName]*TableNameW),
	}
}

// AddTableName adds the AST table name and its corresponding TableNameW to the Context.
func (c *Context) AddTableName(tableNameW *TableNameW) {
	c.tableNames[tableNameW.TableName] = tableNameW
}

// GetTableName returns the TableNameW of the AST table name.
// the TableNameW should have been added to the Context in pre-process phase before
// calling this function, if it doesn't exist, pre-process should have returned error,
// so we don't check nil-ness in most cases.
func (c *Context) GetTableName(tableName *ast.TableName) *TableNameW {
	return c.tableNames[tableName]
}