feat(eo): add request object with validation

Author: twoGiants

hack/generator/request.go

@@ -0,0 +1,91 @@
+package generator
+
+import (
+	"fmt"
+	"path/filepath"
+	"slices"
+)
+
+type InputSource interface {
+	Args() []string
+}
+
+type RequestImpl struct {
+	command,
+	pattern,
+	difficulty string
+	data DocsTemplateData
+}
+
+func NewRequest(
+	source InputSource,
+) (RequestImpl, error) {
+	args := source.Args()
+	if err := validate(args); err != nil {
+		return RequestImpl{}, err
+	}
+
+	result := RequestImpl{
+		args[0],
+		args[1],
+		args[2],
+		NewDocsTemplateData(args[3]),
+	}
+	return result, nil
+}
+
+func validate(args []string) error {
+	doValidate := func(attr string, member string, list []string) error {
+		if !slices.Contains(list, member) {
+			return fmt.Errorf("invalid %s: %s, allowed: %v", attr, member, list)
+		}
+		return nil
+	}
+
+	if len(args) != 4 {
+		return fmt.Errorf("missing command, pattern, difficulty and title")
+	}
+
+	if err := doValidate(
+		"command",
+		args[0],
+		[]string{"create", "delete"},
+	); err != nil {
+		return err
+	}
+
+	if err := doValidate(
+		"pattern",
+		args[1],
+		[]string{"arrays", "bit-manipulation", "stack"},
+	); err != nil {
+		return err
+	}
+
+	if err := doValidate(
+		"difficulty",
+		args[2],
+		[]string{"easy", "medium", "hard"},
+	); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r RequestImpl) Create() bool {
+	return r.command == "create"
+}
+
+func (r RequestImpl) TemplateData() DocsTemplateData {
+	return r.data
+}
+
+func (r RequestImpl) TargetPath(root string) string {
+	return filepath.Join(
+		root,
+		r.pattern,
+		r.difficulty,
+		r.data.SmallTitle,
+	)
+}