package adapters

import (
	"fmt"

	"iop/apps/node/internal/runtime"
)

// Registry holds all registered adapters by name.
type Registry struct {
	adapters map[string]runtime.Adapter
	order    []string // insertion order — first registered is the default
}

func NewRegistry() *Registry {
	return &Registry{adapters: make(map[string]runtime.Adapter)}
}

// Register adds an adapter. The first registered adapter becomes the default.
func (r *Registry) Register(a runtime.Adapter) {
	name := a.Name()
	if _, exists := r.adapters[name]; !exists {
		r.order = append(r.order, name)
	}
	r.adapters[name] = a
}

func (r *Registry) Get(name string) (runtime.Adapter, bool) {
	a, ok := r.adapters[name]
	return a, ok
}

func (r *Registry) Default() string {
	if len(r.order) == 0 {
		return ""
	}
	return r.order[0]
}

// All returns all registered adapters in registration order.
func (r *Registry) All() []runtime.Adapter {
	out := make([]runtime.Adapter, 0, len(r.order))
	for _, name := range r.order {
		out = append(out, r.adapters[name])
	}
	return out
}

// MustGet returns the adapter or panics — useful during bootstrap validation.
func (r *Registry) MustGet(name string) runtime.Adapter {
	a, ok := r.Get(name)
	if !ok {
		panic(fmt.Sprintf("adapter %q not registered", name))
	}
	return a
}