package main
import (
"net/http"
"github.com/graphql-go/graphql"
"context"
"encoding/json"
"io"
"reflect"
"errors"
"fmt"
"sync"
)
func GraphiQLHandler() func(http.ResponseWriter, *http.Request) {
graphiql_string := `
GraphiQL
Loading...
`
return func(w http.ResponseWriter, r * http.Request) {
w.Header().Set("Content-Type", "text/html; charset=utf-8")
w.WriteHeader(http.StatusOK)
io.WriteString(w, graphiql_string)
}
}
type GQLQuery struct {
Query string `json:"query"`
}
func GQLHandler(schema graphql.Schema, ctx context.Context) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r * http.Request) {
str, err := io.ReadAll(r.Body)
if err != nil {
log.Logf("gql", "failed to read request body: %s", err)
return
}
res := GQLQuery{}
json.Unmarshal(str, &res)
result := graphql.Do(graphql.Params{
Schema: schema,
Context: ctx,
RequestString: res.Query,
})
if len(result.Errors) > 0 {
log.Logf("gql", "wrong result, unexpected errors: %v", result.Errors)
}
json.NewEncoder(w).Encode(result)
}
}
func GQLEventFn(p graphql.ResolveParams, fn func(Event, graphql.ResolveParams)(interface{}, error))(interface{}, error) {
if event, ok := p.Source.(Event); ok {
return fn(event, p)
}
return nil, errors.New("Failed to cast source to event")
}
func GQLEventID(p graphql.ResolveParams) (interface{}, error) {
return GQLEventFn(p, func(event Event, p graphql.ResolveParams)(interface{}, error) {
return event.ID(), nil
})
}
func GQLEventName(p graphql.ResolveParams) (interface{}, error) {
return GQLEventFn(p, func(event Event, p graphql.ResolveParams)(interface{}, error) {
return event.Name(), nil
})
}
func GQLEventDescription(p graphql.ResolveParams) (interface{}, error) {
return GQLEventFn(p, func(event Event, p graphql.ResolveParams)(interface{}, error) {
return event.Description(), nil
})
}
func GQLEventChildren(p graphql.ResolveParams) (interface{}, error) {
return GQLEventFn(p, func(event Event, p graphql.ResolveParams)(interface{}, error) {
return event.Children(), nil
})
}
var gql_list_event * graphql.List = nil
func GQLListEvent() * graphql.List {
if gql_list_event == nil {
gql_list_event = graphql.NewList(GQLInterfaceEvent())
}
return gql_list_event
}
var gql_interface_event * graphql.Interface = nil
func GQLInterfaceEvent() * graphql.Interface {
if gql_interface_event == nil {
gql_interface_event = graphql.NewInterface(graphql.InterfaceConfig{
Name: "Event",
ResolveType: func(p graphql.ResolveTypeParams) *graphql.Object {
valid_events, ok := p.Context.Value("valid_events").(map[reflect.Type]*graphql.Object)
if ok == false {
return nil
}
for key, value := range(valid_events) {
if reflect.TypeOf(p.Value) == key {
return value
}
}
return nil
},
Fields: graphql.Fields{},
})
if gql_list_event == nil {
gql_list_event = graphql.NewList(gql_interface_event)
}
gql_interface_event.AddFieldConfig("ID", &graphql.Field{
Type: graphql.String,
})
gql_interface_event.AddFieldConfig("Name", &graphql.Field{
Type: graphql.String,
})
gql_interface_event.AddFieldConfig("Description", &graphql.Field{
Type: graphql.String,
})
gql_interface_event.AddFieldConfig("Children", &graphql.Field{
Type: gql_list_event,
})
}
return gql_interface_event
}
var gql_type_base_event * graphql.Object = nil
func GQLTypeBaseEvent() * graphql.Object {
if gql_type_base_event == nil {
gql_type_base_event = graphql.NewObject(graphql.ObjectConfig{
Name: "BaseEvent",
Interfaces: []*graphql.Interface{
GQLInterfaceEvent(),
},
IsTypeOf: func(p graphql.IsTypeOfParams) bool {
_, ok := p.Value.(*BaseEvent)
return ok
},
Fields: graphql.Fields{},
})
gql_type_base_event.AddFieldConfig("ID", &graphql.Field{
Type: graphql.String,
Resolve: GQLEventID,
})
gql_type_base_event.AddFieldConfig("Name", &graphql.Field{
Type: graphql.String,
Resolve: GQLEventName,
})
gql_type_base_event.AddFieldConfig("Description", &graphql.Field{
Type: graphql.String,
Resolve: GQLEventDescription,
})
gql_type_base_event.AddFieldConfig("Children", &graphql.Field{
Type: GQLListEvent(),
Resolve: GQLEventChildren,
})
}
return gql_type_base_event
}
var gql_type_event_queue * graphql.Object = nil
func GQLTypeEventQueue() * graphql.Object {
if gql_type_event_queue == nil {
gql_type_event_queue = graphql.NewObject(graphql.ObjectConfig{
Name: "EventQueue",
Interfaces: []*graphql.Interface{
GQLInterfaceEvent(),
},
IsTypeOf: func(p graphql.IsTypeOfParams) bool {
_, ok := p.Value.(*EventQueue)
return ok
},
Fields: graphql.Fields{},
})
gql_type_event_queue.AddFieldConfig("ID", &graphql.Field{
Type: graphql.String,
Resolve: GQLEventID,
})
gql_type_event_queue.AddFieldConfig("Name", &graphql.Field{
Type: graphql.String,
Resolve: GQLEventName,
})
gql_type_event_queue.AddFieldConfig("Description", &graphql.Field{
Type: graphql.String,
Resolve: GQLEventDescription,
})
gql_type_event_queue.AddFieldConfig("Children", &graphql.Field{
Type: GQLListEvent(),
Resolve: GQLEventChildren,
})
}
return gql_type_event_queue
}
type GQLServer struct {
BaseResource
abort chan error
listen string
gql_channel chan error
}
func NewGQLServer(listen string) * GQLServer {
server := &GQLServer{
BaseResource: NewBaseResource("GQL Server", "graphql server for event signals", []Resource{}),
listen: listen,
abort: make(chan error, 1),
gql_channel: make(chan error, 1),
}
return server
}
func (server * GQLServer) update(signal GraphSignal) {
server.signal <- signal
server.BaseResource.update(signal)
}
func (server * GQLServer) Handler(extended_types map[reflect.Type]*graphql.Object) func(http.ResponseWriter, *http.Request) {
valid_events := map[reflect.Type]*graphql.Object{}
valid_events[reflect.TypeOf((*BaseEvent)(nil))] = GQLTypeBaseEvent()
valid_events[reflect.TypeOf((*EventQueue)(nil))] = GQLTypeEventQueue()
for go_t, gql_t := range(extended_types) {
valid_events[go_t] = gql_t
}
schemaConfig := graphql.SchemaConfig{
Types: []graphql.Type{GQLTypeBaseEvent(), GQLTypeEventQueue()},
Query: graphql.NewObject(graphql.ObjectConfig{
Name: "Query",
Fields: graphql.Fields{
"Owner": &graphql.Field{
Type: GQLInterfaceEvent(),
Resolve: func(p graphql.ResolveParams) (interface{}, error) {
server.lock_holder_lock.Lock()
defer server.lock_holder_lock.Unlock()
owner := server.Owner()
return owner, nil
},
},
},
}),
}
schema, err := graphql.NewSchema(schemaConfig)
if err != nil{
panic(err)
}
return GQLHandler(schema, context.WithValue(context.Background(), "valid_events", valid_events))
}
func (server * GQLServer) Init(abort chan error) bool {
go func(abort chan error) {
log.Logf("gql", "GOROUTINE_START for %s", server.ID())
mux := http.NewServeMux()
mux.HandleFunc("/gql", server.Handler(map[reflect.Type]*graphql.Object{}))
mux.HandleFunc("/", GraphiQLHandler())
srv := &http.Server{
Addr: server.listen,
Handler: mux,
}
http_done := &sync.WaitGroup{}
http_done.Add(1)
go func(srv *http.Server, http_done *sync.WaitGroup) {
defer http_done.Done()
err := srv.ListenAndServe()
if err != http.ErrServerClosed {
panic(fmt.Sprintf("Failed to start gql server: %s", err))
}
}(srv, http_done)
for true {
select {
case <-abort:
log.Logf("gql", "GOROUTINE_ABORT for %s", server.ID())
err := srv.Shutdown(context.Background())
if err != nil{
panic(fmt.Sprintf("Failed to shutdown gql server: %s", err))
}
http_done.Wait()
break
case signal:=<-server.signal:
log.Logf("gql", "GOROUTINE_SIGNAL for %s: %+v", server.ID(), signal)
// Take signals to resource and send to GQL subscriptions
}
}
}(abort)
return true
}