nix-amer/internal/instruction/reader.go

package instruction

import (
	"strings"
)

// Parse from a raw line
func Parse(raw string) (T, error) {

	// 1. format (trim + split first space)
	cmd := strings.SplitN(raw, " ", 2)
	cmd[0] = strings.Trim(cmd[0], " \t")

	// 2. fail if invalid base syntax 'cmd args...'
	// where command is 3 letters
	if len(cmd) < 2 || len(cmd[0]) < 3 || cmd[0][1] == ' ' {
		return nil, ErrInvalidSyntax
	}
	cmd[1] = strings.Trim(cmd[1], " \t")

	// 3. Extract instruction type
	switch cmd[0] {
	case "ins":
		i := &install{}
		err := i.Build(cmd[1])
		return i, err
	case "del":
		i := &delete{}
		err := i.Build(cmd[1])
		return i, err
	case "ser":
		i := &service{}
		err := i.Build(cmd[1])
		return i, err
	case "cnf":
		i := &config{}
		err := i.Build(cmd[1])
		return i, err
	default:
		return nil, ErrUnknownInstruction
	}

	// return nil, nil
}