package syw

import (
	"bytes"
	"context"
	"errors"
	"os/exec"
	"sync"
)

var mut sync.Mutex
var gitbinpath string

func findbin() string {
	if gitbinpath == "" {
		mut.Lock()
		gitbinpath, _ = exec.LookPath("git")
		mut.Unlock()

		if gitbinpath == "" {
			panic("failed to find 'git' executable")
		}
	}
	return gitbinpath
}

func runCmd(ctx context.Context, args []string) (*cmdResult, error) {
	cmd := exec.CommandContext(ctx, findbin(), args...)

	outbuf := &bytes.Buffer{}
	cmd.Stdout = outbuf
	errbuf := &bytes.Buffer{}
	cmd.Stderr = errbuf

	var eerr *exec.ExitError
	if err := cmd.Run(); err != nil && !errors.As(err, &eerr) {
		return nil, err
	}

	return &cmdResult{
		status: cmd.ProcessState.ExitCode(),
		out:    outbuf,
		err:    errbuf,
	}, nil
}

type cmdResult struct {
	status int
	out    *bytes.Buffer
	err    *bytes.Buffer
}