package main

import (
	"flag"
	"fmt"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"
)

const (
	warmup = 2
	runs   = 10
)

// you'll need to install all fetches :P
// it's easier with nix shell btwww
func main() {
	targetsFlag := flag.String("targets", "", "comma-separated list of commands to benchmark")
	flag.Parse()

	if *targetsFlag == "" {
		log.Fatal("please provide at least one target via -targets")
	}

	targets := parseTargets(*targetsFlag)

	dir := filepath.Join("results", time.Now().Format("2006-01-02"))
	if err := os.MkdirAll(dir, 0o755); err != nil {
		log.Fatal(err)
	}

	jsonOut := filepath.Join(dir, "results.json")
	mdOut := filepath.Join(dir, "results.md")

	args := buildArgs(targets, jsonOut, mdOut)

	cmd := exec.Command("hyperfine", args...)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	fmt.Printf("benchmarking %d targets (%d warmup, %d runs each)\n", len(targets), warmup, runs)
	fmt.Printf("output: %s\n", dir)

	if err := cmd.Run(); err != nil {
		log.Fatalf("hyperfine: %v", err)
	}

	fmt.Printf("results written to %s\n", dir)
}

func parseTargets(input string) []string {
	parts := strings.Split(input, ",")
	var targets []string
	for _, p := range parts {
		p = strings.TrimSpace(p)
		if p != "" {
			targets = append(targets, p)
		}
	}
	return targets
}

func buildArgs(targets []string, jsonOut, mdOut string) []string {
	args := []string{
		"--warmup", fmt.Sprintf("%d", warmup),
		"--runs", fmt.Sprintf("%d", runs),
		"--export-json", jsonOut,
		"--export-markdown", mdOut,
		"--ignore-failure",
		"--shell", "none",
		"--style", "full",
		"--sort", "mean-time",
	}

	for _, t := range targets {
		args = append(args, t)
	}

	return args
}