package runtime
import (
"encoding/json"
"fmt"
"net/url"
"reflect"
"sort"
"strconv"
"strings"
"time"
"github.com/pkg/errors"
"github.com/deepmap/oapi-codegen/pkg/types"
)
func marshalDeepObject(in interface{}, path []string) ([]string, error) {
var result []string
switch t := in.(type) {
case []interface{}:
// For the array, we will use numerical subscripts of the form [x],
// in the same order as the array.
for i, iface := range t {
newPath := append(path, strconv.Itoa(i))
fields, err := marshalDeepObject(iface, newPath)
if err != nil {
return nil, errors.Wrap(err, "error traversing array")
}
result = append(result, fields...)
}
case map[string]interface{}:
// For a map, each key (field name) becomes a member of the path, and
// we recurse. First, sort the keys.
keys := make([]string, len(t))
i := 0
for k := range t {
keys[i] = k
i++
}
sort.Strings(keys)
// Now, for each key, we recursively marshal it.
for _, k := range keys {
newPath := append(path, k)
fields, err := marshalDeepObject(t[k], newPath)
if err != nil {
return nil, errors.Wrap(err, "error traversing map")
}
result = append(result, fields...)
}
default:
// Now, for a concrete value, we will turn the path elements
// into a deepObject style set of subscripts. [a, b, c] turns into
// [a][b][c]
prefix := "[" + strings.Join(path, "][") + "]"
result = []string{
prefix + fmt.Sprintf("=%v", t),
}
}
return result, nil
}
func MarshalDeepObject(i interface{}, paramName string) (string, error) {
// We're going to marshal to JSON and unmarshal into an interface{},
// which will use the json pkg to deal with all the field annotations. We
// can then walk the generic object structure to produce a deepObject. This
// isn't efficient and it would be more efficient to reflect on our own,
// but it's complicated, error-prone code.
buf, err := json.Marshal(i)
if err != nil {
return "", errors.Wrap(err, "failed to marshal input to JSON")
}
var i2 interface{}
err = json.Unmarshal(buf, &i2)
if err != nil {
return "", errors.Wrap(err, "failed to unmarshal JSON")
}
fields, err := marshalDeepObject(i2, nil)
if err != nil {
return "", errors.Wrap(err, "error traversing JSON structure")
}
// Prefix the param name to each subscripted field.
for i := range fields {
fields[i] = paramName + fields[i]
}
return strings.Join(fields, "&"), nil
}
type fieldOrValue struct {
fields map[string]fieldOrValue
value string
}
func (f *fieldOrValue) appendPathValue(path []string, value string) {
fieldName := path[0]
if len(path) == 1 {
f.fields[fieldName] = fieldOrValue{value: value}
return
}
pv, found := f.fields[fieldName]
if !found {
pv = fieldOrValue{
fields: make(map[string]fieldOrValue),
}
f.fields[fieldName] = pv
}
pv.appendPathValue(path[1:], value)
}
func makeFieldOrValue(paths [][]string, values []string) fieldOrValue {
f := fieldOrValue{
fields: make(map[string]fieldOrValue),
}
for i := range paths {
path := paths[i]
value := values[i]
f.appendPathValue(path, value)
}
return f
}
func UnmarshalDeepObject(dst interface{}, paramName string, params url.Values) error {
// Params are all the query args, so we need those that look like
// "paramName["...
var fieldNames []string
var fieldValues []string
searchStr := paramName + "["
for pName, pValues := range params {
if strings.HasPrefix(pName, searchStr) {
// trim the parameter name from the full name.
pName = pName[len(paramName):]
fieldNames = append(fieldNames, pName)
if len(pValues) != 1 {
return fmt.Errorf("%s has multiple values", pName)
}
fieldValues = append(fieldValues, pValues[0])
}
}
// Now, for each field, reconstruct its subscript path and value
paths := make([][]string, len(fieldNames))
for i, path := range fieldNames {
path = strings.TrimLeft(path, "[")
path = strings.TrimRight(path, "]")
paths[i] = strings.Split(path, "][")
}
fieldPaths := makeFieldOrValue(paths, fieldValues)
err := assignPathValues(dst, fieldPaths)
if err != nil {
return errors.Wrap(err, "error assigning value to destination")
}
return nil
}
// This returns a field name, either using the variable name, or the json
// annotation if that exists.
func getFieldName(f reflect.StructField) string {
n := f.Name
tag, found := f.Tag.Lookup("json")
if found {
// If we have a json field, and the first part of it before the
// first comma is non-empty, that's our field name.
parts := strings.Split(tag, ",")
if parts[0] != "" {
n = parts[0]
}
}
return n
}
// Create a map of field names that we'll see in the deepObject to reflect
// field indices on the given type.
func fieldIndicesByJsonTag(i interface{}) (map[string]int, error) {
t := reflect.TypeOf(i)
if t.Kind() != reflect.Struct {
return nil, errors.New("expected a struct as input")
}
n := t.NumField()
fieldMap := make(map[string]int)
for i := 0; i < n; i++ {
field := t.Field(i)
fieldName := getFieldName(field)
fieldMap[fieldName] = i
}
return fieldMap, nil
}
func assignPathValues(dst interface{}, pathValues fieldOrValue) error {
//t := reflect.TypeOf(dst)
v := reflect.ValueOf(dst)
iv := reflect.Indirect(v)
it := iv.Type()
switch it.Kind() {
case reflect.Slice:
sliceLength := len(pathValues.fields)
dstSlice := reflect.MakeSlice(it, sliceLength, sliceLength)
err := assignSlice(dstSlice, pathValues)
if err != nil {
return errors.Wrap(err, "error assigning slice")
}
iv.Set(dstSlice)
return nil
case reflect.Struct:
// Some special types we care about are structs. Handle them
// here.
if _, isDate := iv.Interface().(types.Date); isDate {
var date types.Date
var err error
date.Time, err = time.Parse(types.DateFormat, pathValues.value)
if err != nil {
return errors.Wrap(err, "invalid date format")
}
iv.Set(reflect.ValueOf(date))
}
if _, isTime := iv.Interface().(time.Time); isTime {
var tm time.Time
var err error
tm, err = time.Parse(types.DateFormat, pathValues.value)
if err != nil {
return errors.Wrap(err, "invalid date format")
}
iv.Set(reflect.ValueOf(tm))
}
fieldMap, err := fieldIndicesByJsonTag(iv.Interface())
if err != nil {
return errors.Wrap(err, "failed enumerating fields")
}
for _, fieldName := range sortedFieldOrValueKeys(pathValues.fields) {
fieldValue := pathValues.fields[fieldName]
fieldIndex, found := fieldMap[fieldName]
if !found {
return fmt.Errorf("field [%s] is not present in destination object", fieldName)
}
field := iv.Field(fieldIndex)
err = assignPathValues(field.Addr().Interface(), fieldValue)
if err != nil {
return errors.Wrapf(err, "error assigning field [%s]", fieldName)
}
}
return nil
case reflect.Ptr:
// If we have a pointer after redirecting, it means we're dealing with
// an optional field, such as *string, which was passed in as &foo. We
// will allocate it if necessary, and call ourselves with a different
// interface.
dstVal := reflect.New(it.Elem())
dstPtr := dstVal.Interface()
err := assignPathValues(dstPtr, pathValues)
iv.Set(dstVal)
return err
case reflect.Bool:
val, err := strconv.ParseBool(pathValues.value)
if err != nil {
return fmt.Errorf("expected a valid bool, got %s", pathValues.value)
}
iv.SetBool(val)
return nil
case reflect.Float32:
val, err := strconv.ParseFloat(pathValues.value, 32)
if err != nil {
return fmt.Errorf("expected a valid float, got %s", pathValues.value)
}
iv.SetFloat(val)
return nil
case reflect.Float64:
val, err := strconv.ParseFloat(pathValues.value, 64)
if err != nil {
return fmt.Errorf("expected a valid float, got %s", pathValues.value)
}
iv.SetFloat(val)
return nil
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
val, err := strconv.ParseInt(pathValues.value, 10, 64)
if err != nil {
return fmt.Errorf("expected a valid int, got %s", pathValues.value)
}
iv.SetInt(val)
return nil
case reflect.String:
iv.SetString(pathValues.value)
return nil
default:
return errors.New("unhandled type: " + it.String())
}
}
func assignSlice(dst reflect.Value, pathValues fieldOrValue) error {
// Gather up the values
nValues := len(pathValues.fields)
values := make([]string, nValues)
// We expect to have consecutive array indices in the map
for i := 0; i < nValues; i++ {
indexStr := strconv.Itoa(i)
fv, found := pathValues.fields[indexStr]
if !found {
return errors.New("array deepObjects must have consecutive indices")
}
values[i] = fv.value
}
// This could be cleaner, but we can call into assignPathValues to
// avoid recreating this logic.
for i:=0; i < nValues; i++ {
dstElem := dst.Index(i).Addr()
err := assignPathValues(dstElem.Interface(), fieldOrValue{value:values[i]})
if err != nil {
return errors.Wrap(err, "error binding array")
}
}
return nil
}
func sortedFieldOrValueKeys(m map[string]fieldOrValue) []string {
keys := make([]string, 0, len(m))
for k := range m {
keys = append(keys, k)
}
sort.Strings(keys)
return keys
}