package main

import (
	"fmt"
	"strings"

	"github.com/DataDog/go-sqllexer"
)

type QueryType int

const (
	NONE QueryType = iota
	SELECT
	UPDATE
	INSERT
	DELETE
)

type Query struct {
	Type    QueryType
	FullSql string
	IsValid bool
}

func IsTokenEndOfStatement(token *sqllexer.Token) bool {
	return (token.Type == sqllexer.EOF || token.Value == ";")
}

func GetQueryTypeFromToken(token *sqllexer.Token) QueryType {
	if token.Type != sqllexer.COMMAND {
		return NONE
	}

	var foundType QueryType
	switch strings.ToUpper(token.Value) {
	case "SELECT":
		foundType = SELECT
	case "UPDATE":
		foundType = UPDATE
	case "INSERT":
		foundType = INSERT
	case "DELETE":
		foundType = DELETE
	default:
		foundType = NONE
	}

	return foundType
}

func IsCrudSqlStatement(token *sqllexer.Token) bool {
	queryType := GetQueryTypeFromToken(token)
	return (queryType > 0 && queryType <= 4) // TODO:  Update if QueryTypes Change
}

func GetQueryTypeFromSql(sql string) QueryType {
	var queryType QueryType

	lexer := sqllexer.New(sql)
	for {
		token := lexer.Scan()
		if IsTokenEndOfStatement(token) {
			break
		}

		queryType = GetQueryTypeFromToken(token)
		if queryType > 0 {
			break
		}
	}

	return queryType
}

func main() {
	query := "DELETE * FROM users \n WHERE id = something AND SELECT;"
	newQuery := GetQueryTypeFromSql(query)

	fmt.Println(newQuery)

	//lexer := sqllexer.New(query)
	//for {
	//	token := lexer.Scan()
	//	fmt.Println(token.Value, token.Type)

	//	if token.Type == sqllexer.EOF {
	//		break
	//	}
	//}
}