feat: unifood base with GET dishes (#1)

Features:
- CLI structure with verbs and resources
- Application config and parameters
- Output formatters
- Initial resource: dishes

Reviewed-on: #1
Co-authored-by: bdoerfchen <git@bissendorf.co>
Co-committed-by: bdoerfchen <git@bissendorf.co>

core/interfaces/handler.go

@@ -0,0 +1,29 @@
+package interfaces
+
+import (
+	"context"
+
+	"git.bissendorf.co/bissendorf/unifood/m/v2/core/interfaces/params"
+)
+
+type ResourceCommand[T any] struct {
+	Name        string
+	Aliases     []string
+	Description string
+	Verbs       []Verb
+	Handler     ResourceHandler
+}
+
+type ResourceHandler interface {
+	GetParametersForVerb(verb Verb) []params.Registration
+}
+
+type GetHandler interface {
+	Get(ctx context.Context, params params.Container) (*ResourceList, error)
+}
+
+type Verb string
+
+const (
+	VerbGet Verb = "get"
+)

core/interfaces/http.go

@@ -0,0 +1,7 @@
+package interfaces
+
+import "context"
+
+type QueryClient[T any] interface {
+	Get(ctx context.Context, queryStatement string, selectStatement string, allowCache bool) (*T, error)
+}

core/interfaces/output.go

@@ -0,0 +1,14 @@
+package interfaces
+
+import (
+	"io"
+)
+
+type Formatter interface {
+	Format(object *ResourceList) (io.Reader, error)
+}
+
+type TableOutput interface {
+	ColumnNames() []string
+	Columns() []any
+}

core/interfaces/params/params.go

@@ -0,0 +1,69 @@
+package params
+
+import "errors"
+
+var (
+	ErrParamNotFound = errors.New("parameter not found")
+)
+
+type Registration struct {
+	Name        string
+	ShortHand   string
+	Description string
+	DefaultFunc func() string
+	ParseFunc   ParseFn
+}
+
+type ParseFn func(value string) (any, error)
+
+var ParseString ParseFn = func(value string) (any, error) { return value, nil }
+
+type Container struct {
+	params map[string]Value
+}
+
+type Value struct {
+	value   *string
+	parseFn ParseFn
+}
+
+func (c *Container) Register(key string, parseFn ParseFn) *string {
+	if c.params == nil {
+		c.params = make(map[string]Value)
+	}
+
+	item, exists := c.params[key]
+	if exists {
+		return item.value
+	}
+
+	var str string
+	value := Value{
+		parseFn: parseFn,
+		value:   &str,
+	}
+	c.params[key] = value
+	return value.value
+}
+
+func (c *Container) GetValue(key string) (any, error) {
+	item, exists := c.params[key]
+	if !exists {
+		return nil, ErrParamNotFound
+	}
+
+	return item.parseFn(*item.value)
+}
+
+// Returns a map of all parameters. Parameters that produce errors during parsing are ignored.
+func (c *Container) ToMap() (out map[string]any) {
+	out = make(map[string]any)
+	for key := range c.params {
+		v, err := c.GetValue(key)
+		if err == nil {
+			out[key] = v
+		}
+	}
+
+	return
+}

core/interfaces/resource.go

@@ -0,0 +1,12 @@
+package interfaces
+
+type Resource interface {
+	Kind() string
+
+	Name() string
+}
+
+type ResourceList struct {
+	ItemKind string
+	Items    []Resource
+}