package graphvent
import (
  "reflect"
  "fmt"
  "github.com/graphql-go/graphql"
  "github.com/graphql-go/graphql/language/ast"
)

func ResolveNodeID(p graphql.ResolveParams) (interface{}, error) {
  node, ok := p.Source.(NodeResult)
  if ok == false {
    return nil, fmt.Errorf("Can't get NodeID from %+v", reflect.TypeOf(p.Source))
  }

  return node.NodeID, nil
}

func ResolveNodeTypeHash(p graphql.ResolveParams) (interface{}, error) {
  node, ok := p.Source.(NodeResult)
  if ok == false {
    return nil, fmt.Errorf("Can't get TypeHash from %+v", reflect.TypeOf(p.Source))
  }

  return uint64(node.NodeType), nil
}

func GetFieldNames(ctx *Context, selection_set *ast.SelectionSet) []string {
  names := []string{}
  if selection_set == nil {
    return names
  }

  for _, sel := range(selection_set.Selections) {
    switch field := sel.(type) {
    case *ast.Field:
      names = append(names, field.Name.Value)
    case *ast.InlineFragment:
      names = append(names, GetFieldNames(ctx, field.SelectionSet)...)
    default:
      ctx.Log.Logf("gql", "Unknown selection type: %s", reflect.TypeOf(field))
    }
  }

  return names
}

func GetResolveFields(ctx *Context, p graphql.ResolveParams) []string {
  names := []string{}
  for _, field := range(p.Info.FieldASTs) {
    names = append(names, GetFieldNames(ctx, field.SelectionSet)...)
  }

  return names
}