// Friend is a small struct representing a person.
type Friend struct {
  FirstName string
  Last string `graphql:"lastName"` // use a custom name

  Added time.Date `graphql:"-"` // don't expose over graphql
}

// FullName builds a friend's full name.
func (f *Friend) FullName() string {
  return fmt.Sprintf("%s %s", f.FirstName, f.Last)
}

// registerFriend registers custom resolvers on the Friend type.
//
// Note: registerFriend wouldn't be necessary if the type only
// had the default struct field resolvers above.
func registerFriend(schema *schemabuilder.Schema) {
  object := schema.Object("Friend", Friend{})

  // fullName is a computed field on the Friend{} object.
  object.FieldFunc("fullName", Friend.FullName)
}

// registerQuery registers the resolvers on the core graphql query type.
func registerQuery(schema *schemabuilder.Schema) {
  query := schema.Query()

  // time returns the current time.
  query.FieldFunc("time", func(ctx context.Context) string {
    // Invalidate the result of this resolver after 10 seconds.
    reactive.InvalidateAfter(ctx, 10 * time.Second)
    // Return the current time. Will be re-executed automatically.
    return time.Now().String()
  })
}

// A Post holds a row from the MySQL posts table.
type Post struct {
  Id    int64 `sqlgen:",primary"`
  Title string
}

// Server implements a graphql server. It has persistent handles to eg. the
// database.
type Server struct {
  db *livesql.LiveDB
}

// registerQuery registers the root query resolvers.
func (s *Server) registerQuery(schema *schemabuilder.Schema) {
  query := schema.Query()
  // posts returns all posts in the database.
  query.FieldFunc("posts", func(ctx context.Context) ([]*Post, error) {
    var posts []*Post
    if err := s.db.Query(ctx, &posts, nil, nil); err != nil {
      return nil, err
    }
    return posts, nil
  })
}

type Post struct {
  Id    int64 `sqlgen:",primary"`
  Title string
  AuthorId int64
}

// An Author represents a row in the authors table.
type Author struct {
  Id   int64 `sqlgen:",primary"`
  Name string
}

// registerPost registers resolvers on the Post type.
func (s *Server) registerPost(schema *schemabuilder.Schema) {
  object := schema.Object("post", Post{})
  // author return the Author object corresponding to a Post's AuthorId.
  object.FieldFunc("author", func(ctx context.Context, p *Post) (*Author, error) {
    var author *Author
    if err := s.db.QueryRow(ctx, &author, sqlgen.Filter{"id": p.AuthorId}, nil); err != nil {
      return nil, err
    }
    return author, nil
  })
}

// Expose schema and graphiql.
http.Handle("/graphql", graphql.Handler(schema))
http.Handle("/graphiql/", http.StripPrefix("/graphiql/", graphiql.Handler()))
http.ListenAndServe(":3030", nil)

package common

type User struct {}


package photos

type PhotosServer {}

func (s *PhotosServer) registerUser(schema *schemabuilder.Schema) {
  object := schema.Object("User", common.User{})
  object.FieldFunc("photos", s.fetchUserPhotos)
}


package events

type EventsServer {}

func (s *EventsServer) registerUser(schema *schemabuilder.Schema) {
  object := schema.Object("User", common.User{})
  object.FieldFunc("events", s.fetchUserEvents)
}

package main

import (
  "context"
  "net/http"
  "time"

  "github.com/samsarahq/thunder/graphql"
  "github.com/samsarahq/thunder/graphql/graphiql"
  "github.com/samsarahq/thunder/graphql/introspection"
  "github.com/samsarahq/thunder/graphql/schemabuilder"
  "github.com/samsarahq/thunder/reactive"
)

type post struct {
  Title     string
  Body      string
  CreatedAt time.Time
}

// server is our graphql server.
type server struct {
  posts []post
}

// registerQuery registers the root query type.
func (s *server) registerQuery(schema *schemabuilder.Schema) {
  obj := schema.Query()

  obj.FieldFunc("posts", func() []post {
    return s.posts
  })
}

// registerMutation registers the root mutation type.
func (s *server) registerMutation(schema *schemabuilder.Schema) {
  obj := schema.Mutation()
  obj.FieldFunc("echo", func(args struct{ Message string }) string {
    return args.Message
  })
}

// registerPost registers the post type.
func (s *server) registerPost(schema *schemabuilder.Schema) {
  obj := schema.Object("Post", post{})
  obj.FieldFunc("age", func(ctx context.Context, p *post) string {
    reactive.InvalidateAfter(ctx, 5*time.Second)
    return time.Since(p.CreatedAt).String()
  })
}

// schema builds the graphql schema.
func (s *server) schema() *graphql.Schema {
  builder := schemabuilder.NewSchema()
  s.registerQuery(builder)
  s.registerMutation(builder)
  s.registerPost(builder)
  return builder.MustBuild()
}

func main() {
  // Instantiate a server, build a server, and serve the schema on port 3030.
  server := &server{
    posts: []post{
      {Title: "first post!", Body: "I was here first!", CreatedAt: time.Now()},
      {Title: "graphql", Body: "did you hear about Thunder?", CreatedAt: time.Now()},
    },
  }

  schema := server.schema()
  introspection.AddIntrospectionToSchema(schema)

  // Expose schema and graphiql.
  http.Handle("/graphql", graphql.Handler(schema))
  http.Handle("/graphiql/", http.StripPrefix("/graphiql/", graphiql.Handler()))
  http.ListenAndServe(":3030", nil)
}

func main() {
  // Instantiate a server, build a server, and serve the schema on port 3030.
  server := &server{
    posts: []post{
      {Title: "first post!", Body: "I was here first!", CreatedAt: time.Now()},
      {Title: "graphql", Body: "did you hear about Thunder?", CreatedAt: time.Now()},
    },
  }

  schema := server.schema()
  introspection.AddIntrospectionToSchema(schema)

  // Expose GraphQL POST endpoint.
  http.Handle("/graphql", graphql.HTTPHandler(schema))
  http.ListenAndServe(":3030", nil)
}

// schema_generator.go

func main() {
  // Instantiate a server and run the introspection query on it.
  server := &server{...}

  builderSchema := schemabuilder.NewSchema()
  server.registerQuery(builderSchema)
  server.registerMutation(builderSchema)
  // ...

  valueJSON, err := introspection.ComputeSchemaJSON(*builderSchema)
  if err != nil {
    panic(err)
  }

  fmt.Print(string(valueJSON))
}