package executer

import (
	"fmt"
	"log/slog"
	"time"

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

type Executor struct {
	Config *config.Config
}

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

func (e Executor) Run(expr *lambda.Expression) (*Results, error) {
	results := &Results{}

	if e.Config.Profile != "" {
		profiler := Profiler{File: e.Config.Profile}
		if err := profiler.Start(); err != nil {
			return nil, err
		}
		defer profiler.End()
	}

	start := time.Now()

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

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

	results.TimeElapsed = uint64(time.Since(start).Milliseconds())
	return results, nil
}