package validator

import (
	"fmt"

	"github.com/xeipuuv/gojsonschema"
	"sigs.k8s.io/yaml"
)

// InvalidResourceError is returned when a resource does not conform to
// the associated schema
type InvalidResourceError struct{ err string }

func (r InvalidResourceError) Error() string {
	return r.err
}

// ValidFormat is a type for quickly forcing
// new formats on the gojsonschema loader
type ValidFormat struct{}

// ValidFormat is a type for quickly forcing
// new formats on the gojsonschema loader
func (f ValidFormat) IsFormat(input interface{}) bool {
	return true
}

// From kubeval - let's see if absolutely necessary
// func init () {
// 	gojsonschema.FormatCheckers.Add("int64", ValidFormat{})
// 	gojsonschema.FormatCheckers.Add("byte", ValidFormat{})
// 	gojsonschema.FormatCheckers.Add("int32", ValidFormat{})
// 	gojsonschema.FormatCheckers.Add("int-or-string", ValidFormat{})
// }

// Validate validates a single Kubernetes resource against a Json Schema
func Validate(rawResource []byte, schema *gojsonschema.Schema) error {
	if schema == nil {
		return nil
	}

	var resource map[string]interface{}
	if err := yaml.Unmarshal(rawResource, &resource); err != nil {
		return fmt.Errorf("error unmarshalling resource: %s", err)
	}
	resourceLoader := gojsonschema.NewGoLoader(resource)

	results, err := schema.Validate(resourceLoader)
	if err != nil {
		// This error can only happen if the Object to validate is poorly formed. There's no hope of saving this one
		return fmt.Errorf("problem validating schema. Check JSON formatting: %s", err)
	}

	if results.Valid() {
		return nil
	}

	msg := ""
	for _, errMsg := range results.Errors() {
		if msg != "" {
			msg += " - "
		}
		msg += errMsg.Description()
	}
	return InvalidResourceError{err: msg}
}