github.com/erda-project/erda-infra@v1.0.9/providers/httpserver/data_bind.go

// Copyright (c) 2021 Terminus, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package httpserver

import (
	"bytes"
	"encoding"
	"encoding/json"
	"encoding/xml"
	"errors"
	"fmt"
	"io/ioutil"
	"net/http"
	"reflect"
	"strconv"
	"strings"

	"github.com/labstack/echo"
)

type dataBinder struct{}

// Bind implements the `Binder#Bind` function.
func (b *dataBinder) Bind(i interface{}, c echo.Context) (err error) {
	req := c.Request()
	if req.ContentLength > 0 {
		ctype := req.Header.Get(echo.HeaderContentType)
		if len(ctype) <= 0 {
			ctype = echo.MIMEApplicationJSON
		}
		body, err := ioutil.ReadAll(req.Body)
		if err != nil {
			return fmt.Errorf("fail to read body: %s", err)
		}
		req.Body = ioutil.NopCloser(bytes.NewBuffer(body))
		switch {
		case strings.HasPrefix(ctype, echo.MIMEApplicationJSON):
			if err = json.Unmarshal(body, i); err != nil {
				if ute, ok := err.(*json.UnmarshalTypeError); ok {
					return echo.NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Unmarshal type error: expected=%v, got=%v, field=%v, offset=%v", ute.Type, ute.Value, ute.Field, ute.Offset)).SetInternal(err)
				} else if se, ok := err.(*json.SyntaxError); ok {
					return echo.NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Syntax error: offset=%v, error=%v", se.Offset, se.Error())).SetInternal(err)
				}
				return echo.NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
			}
		case strings.HasPrefix(ctype, echo.MIMEApplicationXML), strings.HasPrefix(ctype, echo.MIMETextXML):
			if err = xml.Unmarshal(body, i); err != nil {
				if ute, ok := err.(*xml.UnsupportedTypeError); ok {
					return echo.NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Unsupported type error: type=%v, error=%v", ute.Type, ute.Error())).SetInternal(err)
				} else if se, ok := err.(*xml.SyntaxError); ok {
					return echo.NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Syntax error: line=%v, error=%v", se.Line, se.Error())).SetInternal(err)
				}
				return echo.NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
			}
		case strings.HasPrefix(ctype, echo.MIMEApplicationForm), strings.HasPrefix(ctype, echo.MIMEMultipartForm):
			params, err := c.FormParams()
			if err != nil {
				return echo.NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
			}
			if err = b.bindData(i, params, "form"); err != nil {
				return echo.NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
			}
		default:
			return echo.ErrUnsupportedMediaType
		}
	}
	typ := reflect.TypeOf(i)
	for typ.Kind() == reflect.Ptr {
		typ = typ.Elem()
	}
	if typ.Kind() == reflect.Struct {
		if err = b.bindData(i, c.QueryParams(), "query"); err != nil {
			return echo.NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
		}
		params := map[string][]string{}
		if ctx, ok := c.(*context); ok && len(ctx.vars) > 0 {
			for k, v := range ctx.vars {
				params[k] = []string{v}
			}
		} else {
			names := c.ParamNames()
			values := c.ParamValues()
			for i, name := range names {
				params[name] = []string{values[i]}
			}
		}
		if err := b.bindData(i, params, "param"); err != nil {
			return echo.NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
		}
	}
	return
}

func (b *dataBinder) bindData(ptr interface{}, data map[string][]string, tag string) error {
	if ptr == nil || len(data) == 0 {
		return nil
	}
	typ := reflect.TypeOf(ptr).Elem()
	val := reflect.ValueOf(ptr).Elem()

	// Map
	if typ.Kind() == reflect.Map {
		for k, v := range data {
			val.SetMapIndex(reflect.ValueOf(k), reflect.ValueOf(v[0]))
		}
		return nil
	}

	// !struct
	if typ.Kind() != reflect.Struct {
		return errors.New("binding element must be a struct")
	}

	for i := 0; i < typ.NumField(); i++ {
		typeField := typ.Field(i)
		structField := val.Field(i)
		if !structField.CanSet() {
			continue
		}
		structFieldKind := structField.Kind()
		inputFieldName := typeField.Tag.Get(tag)

		if inputFieldName == "" {
			inputFieldName = typeField.Name
			// If tag is nil, we inspect if the field is a struct.
			if _, ok := structField.Addr().Interface().(echo.BindUnmarshaler); !ok && structFieldKind == reflect.Struct {
				if err := b.bindData(structField.Addr().Interface(), data, tag); err != nil {
					return err
				}
				continue
			}
		}

		inputValue, exists := data[inputFieldName]
		if !exists {
			// Go json.Unmarshal supports case insensitive binding.  However the
			// url params are bound case sensitive which is inconsistent.  To
			// fix this we must check all of the map values in a
			// case-insensitive search.
			for k, v := range data {
				if strings.EqualFold(k, inputFieldName) {
					inputValue = v
					exists = true
					break
				}
			}
		}

		if !exists {
			continue
		}

		// Call this first, in case we're dealing with an alias to an array type
		if ok, err := unmarshalField(typeField.Type.Kind(), inputValue[0], structField); ok {
			if err != nil {
				return err
			}
			continue
		}

		numElems := len(inputValue)
		if structFieldKind == reflect.Slice && numElems > 0 {
			sliceOf := structField.Type().Elem().Kind()
			slice := reflect.MakeSlice(structField.Type(), numElems, numElems)
			for j := 0; j < numElems; j++ {
				if err := setWithProperType(sliceOf, inputValue[j], slice.Index(j)); err != nil {
					return err
				}
			}
			val.Field(i).Set(slice)
		} else if err := setWithProperType(typeField.Type.Kind(), inputValue[0], structField); err != nil {
			return err

		}
	}
	return nil
}

func setWithProperType(valueKind reflect.Kind, val string, structField reflect.Value) error {
	// But also call it here, in case we're dealing with an array of BindUnmarshalers
	if ok, err := unmarshalField(valueKind, val, structField); ok {
		return err
	}

	switch valueKind {
	case reflect.Ptr:
		return setWithProperType(structField.Elem().Kind(), val, structField.Elem())
	case reflect.Int:
		return setIntField(val, 0, structField)
	case reflect.Int8:
		return setIntField(val, 8, structField)
	case reflect.Int16:
		return setIntField(val, 16, structField)
	case reflect.Int32:
		return setIntField(val, 32, structField)
	case reflect.Int64:
		return setIntField(val, 64, structField)
	case reflect.Uint:
		return setUintField(val, 0, structField)
	case reflect.Uint8:
		return setUintField(val, 8, structField)
	case reflect.Uint16:
		return setUintField(val, 16, structField)
	case reflect.Uint32:
		return setUintField(val, 32, structField)
	case reflect.Uint64:
		return setUintField(val, 64, structField)
	case reflect.Bool:
		return setBoolField(val, structField)
	case reflect.Float32:
		return setFloatField(val, 32, structField)
	case reflect.Float64:
		return setFloatField(val, 64, structField)
	case reflect.String:
		structField.SetString(val)
	default:
		return errors.New("unknown type")
	}
	return nil
}

func unmarshalField(valueKind reflect.Kind, val string, field reflect.Value) (bool, error) {
	switch valueKind {
	case reflect.Ptr:
		return unmarshalFieldPtr(val, field)
	default:
		return unmarshalFieldNonPtr(val, field)
	}
}

func unmarshalFieldNonPtr(value string, field reflect.Value) (bool, error) {
	fieldIValue := field.Addr().Interface()
	if unmarshaler, ok := fieldIValue.(echo.BindUnmarshaler); ok {
		return true, unmarshaler.UnmarshalParam(value)
	}
	if unmarshaler, ok := fieldIValue.(encoding.TextUnmarshaler); ok {
		return true, unmarshaler.UnmarshalText([]byte(value))
	}

	return false, nil
}

func unmarshalFieldPtr(value string, field reflect.Value) (bool, error) {
	if field.IsNil() {
		// Initialize the pointer to a nil value
		field.Set(reflect.New(field.Type().Elem()))
	}
	return unmarshalFieldNonPtr(value, field.Elem())
}

func setIntField(value string, bitSize int, field reflect.Value) error {
	if value == "" {
		value = "0"
	}
	intVal, err := strconv.ParseInt(value, 10, bitSize)
	if err == nil {
		field.SetInt(intVal)
	}
	return err
}

func setUintField(value string, bitSize int, field reflect.Value) error {
	if value == "" {
		value = "0"
	}
	uintVal, err := strconv.ParseUint(value, 10, bitSize)
	if err == nil {
		field.SetUint(uintVal)
	}
	return err
}

func setBoolField(value string, field reflect.Value) error {
	if value == "" {
		value = "false"
	}
	boolVal, err := strconv.ParseBool(value)
	if err == nil {
		field.SetBool(boolVal)
	}
	return err
}

func setFloatField(value string, bitSize int, field reflect.Value) error {
	if value == "" {
		value = "0.0"
	}
	floatVal, err := strconv.ParseFloat(value, bitSize)
	if err == nil {
		field.SetFloat(floatVal)
	}
	return err
}