package graphql
import (
"context"
"fmt"
"github.com/vektah/gqlparser/ast"
)
type ExecutableSchema interface {
Schema() *ast.Schema
Complexity(typeName, fieldName string, childComplexity int, args map[string]interface{}) (int, bool)
Query(ctx context.Context, op *ast.OperationDefinition) *Response
Mutation(ctx context.Context, op *ast.OperationDefinition) *Response
Subscription(ctx context.Context, op *ast.OperationDefinition) func() *Response
}
func CollectFields(ctx context.Context, selSet ast.SelectionSet, satisfies []string) []CollectedField {
return collectFields(GetRequestContext(ctx), selSet, satisfies, map[string]bool{})
}
func collectFields(reqCtx *RequestContext, selSet ast.SelectionSet, satisfies []string, visited map[string]bool) []CollectedField {
var groupedFields []CollectedField
for _, sel := range selSet {
switch sel := sel.(type) {
case *ast.Field:
if !shouldIncludeNode(sel.Directives, reqCtx.Variables) {
continue
}
f := getOrCreateField(&groupedFields, sel.Alias, func() CollectedField {
return CollectedField{Field: sel}
})
f.Selections = append(f.Selections, sel.SelectionSet...)
case *ast.InlineFragment:
if !shouldIncludeNode(sel.Directives, reqCtx.Variables) || !instanceOf(sel.TypeCondition, satisfies) {
continue
}
for _, childField := range collectFields(reqCtx, sel.SelectionSet, satisfies, visited) {
f := getOrCreateField(&groupedFields, childField.Name, func() CollectedField { return childField })
f.Selections = append(f.Selections, childField.Selections...)
}
case *ast.FragmentSpread:
if !shouldIncludeNode(sel.Directives, reqCtx.Variables) {
continue
}
fragmentName := sel.Name
if _, seen := visited[fragmentName]; seen {
continue
}
visited[fragmentName] = true
fragment := reqCtx.Doc.Fragments.ForName(fragmentName)
if fragment == nil {
// should never happen, validator has already run
panic(fmt.Errorf("missing fragment %s", fragmentName))
}
if !instanceOf(fragment.TypeCondition, satisfies) {
continue
}
for _, childField := range collectFields(reqCtx, fragment.SelectionSet, satisfies, visited) {
f := getOrCreateField(&groupedFields, childField.Name, func() CollectedField { return childField })
f.Selections = append(f.Selections, childField.Selections...)
}
default:
panic(fmt.Errorf("unsupported %T", sel))
}
}
return groupedFields
}
type CollectedField struct {
*ast.Field
Selections ast.SelectionSet
}
func instanceOf(val string, satisfies []string) bool {
for _, s := range satisfies {
if val == s {
return true
}
}
return false
}
func getOrCreateField(c *[]CollectedField, name string, creator func() CollectedField) *CollectedField {
for i, cf := range *c {
if cf.Alias == name {
return &(*c)[i]
}
}
f := creator()
*c = append(*c, f)
return &(*c)[len(*c)-1]
}
func shouldIncludeNode(directives ast.DirectiveList, variables map[string]interface{}) bool {
skip, include := false, true
if d := directives.ForName("skip"); d != nil {
skip = resolveIfArgument(d, variables)
}
if d := directives.ForName("include"); d != nil {
include = resolveIfArgument(d, variables)
}
return !skip && include
}
func resolveIfArgument(d *ast.Directive, variables map[string]interface{}) bool {
arg := d.Arguments.ForName("if")
if arg == nil {
panic(fmt.Sprintf("%s: argument 'if' not defined", d.Name))
}
value, err := arg.Value.Value(variables)
if err != nil {
panic(err)
}
ret, ok := value.(bool)
if !ok {
panic(fmt.Sprintf("%s: argument 'if' is not a boolean", d.Name))
}
return ret
}
