package instruction

import (
	"fmt"
	"os"
	"strings"
)

type copy struct {
	raw string
	Src string
	Dst string
}

func (d *copy) Raw() string { return strings.Join([]string{"copy", d.raw}, " ") }

func (d *copy) Build(_args string) error {

	// 1. extract action (sub command)
	split := strings.Split(_args, " ")

	// 2. check syntax
	if len(split) != 2 {
		return ErrInvalidSyntax
	}

	d.Src = strings.Trim(split[0], " \t")
	d.Dst = strings.Trim(split[1], " \t")
	d.raw = _args
	return nil
}

func (d copy) Exec(ctx ExecutionContext) ([]byte, error) {

	// 1. fail if source file not found
	if _, err := os.Stat(d.Src); os.IsNotExist(err) {
		return nil, fmt.Errorf("cannot find script '%s'", d.Src)
	}

	// 2. execute script
	if err := ctx.Executor.Command("cp", d.Src, d.Dst).Run(); err != nil {
		return nil, fmt.Errorf("cannot copy '%s' to '%s' | %s", d.Src, d.Dst, err)
	}

	return nil, nil

}