Adding Rules with dynamic WHEN statement

[rishijain300900]

I am working on a POC.

What the Code Does:
Idea is to take CUS(Customer) Turnover and Spl_permission from CLI and the LIMIT turnover limit from SQL DB, and check all the values of customer against the LIMIT.turnoverLimit (in the follwing code i read only 1 LIMIT.turnoverLimit from the SQL and use it against all the customer values that i get from CLI).

Rules.grl:

rule CheckTurnoverLimitLessF "Check the turnover limit" salience 1{
    when 
        CUS.turnover < LIMIT.turnoverLimit && CUS.spl_permission == false
    then
        CUS.SetStatus("OK");
        Retract("CheckTurnoverLimitLessF");
}
rule CheckTurnoverLimitLessT "Check the turnover limit" salience 2{
    when 
        CUS.turnover < LIMIT.turnoverLimit && CUS.spl_permission == true
    then
        CUS.SetStatus("OK");
        Retract("CheckTurnoverLimitLessT");
}
rule CheckTurnoverLimitGreaterF "Check the turnover limit" salience 3{
    when 
        CUS.turnover >= LIMIT.turnoverLimit && CUS.spl_permission == true
    then
        CUS.SetStatus("OK");
        Retract("CheckTurnoverLimitGreaterF");
}
rule CheckTurnoverLimitGreaterT "Check the turnover limit" salience 4{
    when 
        CUS.turnover >= LIMIT.turnoverLimit && CUS.spl_permission == false
    then
        CUS.SetStatus("NOT OK");
        Retract("CheckTurnoverLimitGreaterT");
}

What is the problem that i am facing:
Refer the main.go to understand the problem.
You can notice that after taking the CLI input from the infinite for loop, i have to repeat the following steps everytime:

knowledgeLibrary := ast.NewKnowledgeLibrary()
ruleBuilder := builder.NewRuleBuilder(knowledgeLibrary)
fileRes := pkg.NewFileResource("./rules.grl")
err = ruleBuilder.BuildRuleFromResource("TutorialRules", "0.0.1", fileRes)
if err != nil {
	panic(err)
}
knowledgeBase := knowledgeLibrary.NewKnowledgeBaseInstance("TutorialRules", "0.0.1")
engine := engine.NewGruleEngine()

making the code slow and very much redundant, and as soon as i shift these line before the for loop, the output is not desired one.
Need to optimise this, and also if any suggestion on how my usage of grule can improved will be more than helpful

main.go:

package main

import (
	"bufio"
	"database/sql"
	"fmt"
	"log"
	"os"

	_ "github.com/go-sql-driver/mysql"

	"github.com/hyperjumptech/grule-rule-engine/ast"
	"github.com/hyperjumptech/grule-rule-engine/builder"
	"github.com/hyperjumptech/grule-rule-engine/engine"
	"github.com/hyperjumptech/grule-rule-engine/pkg"
)

type order struct {
	turnover       int64
	cusID          string
	status         string
	spl_permission bool
}

func (o *order) SetStatus(str string) {
	o.status = str
	fmt.Println("User Status: ", o.status)
}

type limit struct {
	turnoverLimit int64
}

func SqlConnect(limit *limit) {
        //connects to a SQL DB and populates the limit struct instance
}

func main() {
	reader := bufio.NewReader(os.Stdin)
	var limit limit
	SqlConnect(&limit)
	for {
		user := &order{
			status: "ND",
		}
		fmt.Println("\nEnter ID and Current Turnover: ")
		text, _ := reader.ReadString('\n')
		user.cusID = text
		var z int
		_, err := fmt.Scanf("%d", &z)
		if err != nil {
			panic(err)
		}
		user.turnover = (int64)(z)
		fmt.Println("\nDoes User have speical permission(Y/N): ")
		text, _ = reader.ReadString('\n')
		text = text[:1]
		if text == "y" || text == "Y" {
			user.spl_permission = true
		} else {
			user.spl_permission = false
		}
		dataCtx := ast.NewDataContext()
		err = dataCtx.Add("LIMIT", limit)
		if err != nil {
			panic(err)
		}
		err = dataCtx.Add("CUS", user)
		if err != nil {
			panic(err)
		}
		knowledgeLibrary := ast.NewKnowledgeLibrary()
		ruleBuilder := builder.NewRuleBuilder(knowledgeLibrary)
		fileRes := pkg.NewFileResource("./rules.grl")
		err = ruleBuilder.BuildRuleFromResource("TutorialRules", "0.0.1", fileRes)
		if err != nil {
			panic(err)
		}
		knowledgeBase := knowledgeLibrary.NewKnowledgeBaseInstance("TutorialRules", "0.0.1")
		engine := engine.NewGruleEngine()
		err = engine.Execute(dataCtx, knowledgeBase)
		if err != nil {
			panic(err)
		}
	}
}

[newm4n]

You can reuse the engine and KnowledgeBase again and again....
How about this...

package main

import (
	"bufio"
	"database/sql"
	"fmt"
	"log"
	"os"

	_ "github.com/go-sql-driver/mysql"

	"github.com/hyperjumptech/grule-rule-engine/ast"
	"github.com/hyperjumptech/grule-rule-engine/builder"
	"github.com/hyperjumptech/grule-rule-engine/engine"
	"github.com/hyperjumptech/grule-rule-engine/pkg"
)

type order struct {
	turnover       int64
	cusID          string
	status         string
	spl_permission bool
}

func (o *order) SetStatus(str string) {
	o.status = str
	fmt.Println("User Status: ", o.status)
}

type limit struct {
	turnoverLimit int64
}

func SqlConnect(limit *limit) {
        //connects to a SQL DB and populates the limit struct instance
}

func main() {
	reader := bufio.NewReader(os.Stdin)
	var limit limit
	SqlConnect(&limit)

	// Prepare grule rule engine
	knowledgeLibrary := ast.NewKnowledgeLibrary()
	ruleBuilder := builder.NewRuleBuilder(knowledgeLibrary)
	fileRes := pkg.NewFileResource("./rules.grl")
	err = ruleBuilder.BuildRuleFromResource("TutorialRules", "0.0.1", fileRes)
	if err != nil {
		panic(err)
	}
	knowledgeBase := knowledgeLibrary.NewKnowledgeBaseInstance("TutorialRules", "0.0.1")
	engine := engine.NewGruleEngine()

	// Take CLI Input
	for {
		user := &order{
			status: "ND",
		}
		fmt.Println("\nEnter ID and Current Turnover: ")
		text, _ := reader.ReadString('\n')
		user.cusID = text
		var z int
		_, err := fmt.Scanf("%d", &z)
		if err != nil {
			panic(err)
		}
		user.turnover = (int64)(z)
		fmt.Println("\nDoes User have speical permission(Y/N): ")
		text, _ = reader.ReadString('\n')
		text = text[:1]
		if text == "y" || text == "Y" {
			user.spl_permission = true
		} else {
			user.spl_permission = false
		}

		// Prepare the context
		dataCtx := ast.NewDataContext()
		err = dataCtx.Add("LIMIT", limit)
		if err != nil {
			panic(err)
		}
		err = dataCtx.Add("CUS", user)
		if err != nil {
			panic(err)
		}
		
		// Just execute/reuse the engine
		err = engine.Execute(dataCtx, knowledgeBase)
		if err != nil {
			panic(err)
		}
	}
}

[rishijain300900]

Ideally this should have worked and i tried this too, but the output that i get after this is very strange.
it executes the rules correctly for first 3-4 CLI inputs but after that it just doesn't print anything (No Output).

In the last 2 cases where ID is chd and xyz, you'll notice no output is reflected (Neither OK nor NOT OK)

[rishijain300900]

So i tried one more thing which works

I moved this block outside the for loop

knowledgeLibrary := ast.NewKnowledgeLibrary()
ruleBuilder := builder.NewRuleBuilder(knowledgeLibrary)
fileRes := pkg.NewFileResource("./rules.grl")
err := ruleBuilder.BuildRuleFromResource("TutorialRules", "0.0.1", fileRes)

and kept this inside the for loop

knowledgeBase := knowledgeLibrary.NewKnowledgeBaseInstance("TutorialRules", "0.0.1")
engine := engine.NewGruleEngine()

Qusetion:
What is the memory and time overhead if I follow this?
Any other thing that i can try for this particular use case.

Code:

package main
import (
	"bufio"
	"database/sql"
	"fmt"
	"log"
	"os"

	_ "github.com/go-sql-driver/mysql"

	"github.com/hyperjumptech/grule-rule-engine/ast"
	"github.com/hyperjumptech/grule-rule-engine/builder"
	"github.com/hyperjumptech/grule-rule-engine/engine"
	"github.com/hyperjumptech/grule-rule-engine/pkg"
)

type order struct {
	turnover       int64
	cusID          string
	status         string
	spl_permission bool
}

func (o *order) SetStatus(str string) {
	o.status = str
	fmt.Println("User Status: ", o.status)
}

type limit struct {
	turnoverLimit int64
}

func SqlConnect(limit *limit) {
       //connects to a SQL DB and populates the limit struct instance
}

func main() {
	reader := bufio.NewReader(os.Stdin)
	var limit limit
	SqlConnect(&limit)
	knowledgeLibrary := ast.NewKnowledgeLibrary()
	ruleBuilder := builder.NewRuleBuilder(knowledgeLibrary)
	fileRes := pkg.NewFileResource("./rules.grl")
	err := ruleBuilder.BuildRuleFromResource("TutorialRules", "0.0.1", fileRes)
	if err != nil {
		panic(err)
	}
	for {
		user := &order{
			status: "ND",
		}
		fmt.Println("\nEnter ID and Current Turnover: ")
		text, _ := reader.ReadString('\n')
		user.cusID = text
		var z int
		_, err := fmt.Scanf("%d", &z)
		if err != nil {
			panic(err)
		}
		user.turnover = (int64)(z)
		fmt.Println("\nDoes User have speical permission(Y/N): ")
		text, _ = reader.ReadString('\n')
		text = text[:1]
		if text == "y" || text == "Y" {
			user.spl_permission = true
		} else {
			user.spl_permission = false
		}
		dataCtx := ast.NewDataContext()
		err = dataCtx.Add("LIMIT", limit)
		if err != nil {
			panic(err)
		}
		err = dataCtx.Add("CUS", user)
		if err != nil {
			panic(err)
		}
		knowledgeBase := knowledgeLibrary.NewKnowledgeBaseInstance("TutorialRules", "0.0.1")
		engine := engine.NewGruleEngine()
		err = engine.Execute(dataCtx, knowledgeBase)
		if err != nil {
			panic(err)
		}
	}
}