package executer

import (
	"fmt"
	"log/slog"

	"git.maximhutz.com/max/lambda/internal/config"
	"git.maximhutz.com/max/lambda/pkg/emitter"
	"git.maximhutz.com/max/lambda/pkg/lambda"
)

type Executor struct {
	Config *config.Config
	emitter.Emitter
}

func New(config *config.Config) *Executor {
	return &Executor{Config: config}
}

func (e Executor) Run(expr *lambda.Expression) {
	e.Emit("start")

	if e.Config.Explanation {
		fmt.Println(lambda.Stringify(*expr))
	}

	for lambda.ReduceOnce(expr) {
		e.Emit("step")
		if e.Config.Verbose {
			slog.Info("reduction", "tree", lambda.Stringify(*expr))
		}
		if e.Config.Explanation {
			fmt.Println("    =", lambda.Stringify(*expr))
		}
	}

	e.Emit("end")
}