package graphql

import (
	"errors"
	"fmt"
	"reflect"
	"strings"

	"github.com/aerogo/aero"

	"github.com/aerogo/graphql"
	"github.com/animenotifier/arn"
)

var (
	empty              = struct{}{}
	privateCollections = map[string]struct{}{
		"PayPalPayment": empty,
		"Purchase":      empty,
		"EmailToUser":   empty,
		"Session":       empty,
		"EditLogEntry":  empty,
	}
)

func Install(app *aero.Application) {
	api := graphql.New(arn.DB)

	// Block private collections
	api.AddRootResolver(func(name string, arguments graphql.Map) (interface{}, error, bool) {
		typeName := strings.TrimPrefix(name, "all")
		typeName = strings.TrimPrefix(typeName, "like")
		_, private := privateCollections[typeName]

		if private {
			return nil, fmt.Errorf("Type '%s' is private", typeName), true
		}

		return nil, nil, false
	})

	// Like objects
	api.AddRootResolver(func(name string, arguments graphql.Map) (interface{}, error, bool) {
		if !strings.HasPrefix(name, "like") {
			return nil, nil, false
		}

		id, ok := arguments["ID"].(string)

		if !ok {
			return nil, fmt.Errorf("'%s' needs to specify an ID", name), true
		}

		typeName := strings.TrimPrefix(name, "like")
		obj, err := arn.DB.Get(typeName, id)

		if err != nil {
			return nil, err, true
		}

		field := reflect.ValueOf(obj).Elem().FieldByName("IsDraft")

		if field.IsValid() && field.Bool() {
			return nil, errors.New("Drafts need to be published before they can be liked"), true
		}

		likeable, ok := obj.(arn.Likeable)

		if !ok {
			return nil, fmt.Errorf("'%s' does not implement the Likeable interface", name), true
		}

		// TODO: Authentication
		// user := GetUserFromContext(ctx)

		// if user == nil {
		// 	return errors.New("Not logged in")
		// }

		// likeable.Like(user.ID)

		// Call OnLike if the object implements it
		// receiver, ok := likeable.(LikeEventReceiver)

		// if ok {
		// 	receiver.OnLike(user)
		// }

		likeable.Save()
		return obj, nil, true
	})

	app.Post("/graphql", api.Handler())
}