package spec

import (
	"encoding/json"

	"github.com/pkg/errors"
	"github.com/qri-io/jsonschema"
)

type Registry struct {
	definitions map[string]map[string][]byte
}

func (r *Registry) Register(name string, version string, schema []byte) error {
	// Assert that provided schema is valid
	if err := json.Unmarshal(schema, &jsonschema.Schema{}); err != nil {
		return errors.WithStack(err)
	}

	specDefinitions, exists := r.definitions[name]
	if !exists {
		specDefinitions = make(map[string][]byte)
	}

	specDefinitions[version] = schema

	r.definitions[name] = specDefinitions

	return nil
}

func (r *Registry) Walk(fn func(name string, version string, schema []byte) error) error {
	for name, specDefinitions := range r.definitions {
		for version, schema := range specDefinitions {
			if err := fn(name, version, schema); err != nil {
				return errors.WithStack(err)
			}
		}
	}

	return nil
}

func NewRegistry() *Registry {
	return &Registry{
		definitions: make(map[string]map[string][]byte),
	}
}

var defaultRegistry = NewRegistry()

func Register(name string, version string, schema []byte) error {
	if err := defaultRegistry.Register(name, version, schema); err != nil {
		return errors.WithStack(err)
	}

	return nil
}

func Walk(fn func(name string, version string, schema []byte) error) error {
	if err := defaultRegistry.Walk(fn); err != nil {
		return errors.WithStack(err)
	}

	return nil
}