// Copyright 2014 Manu Martinez-Almeida.  All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.

package binding

import (
	"mime/multipart"
	"net/http"
	"reflect"

	"github.com/gin-gonic/gin/binding/common"
)

const defaultMemory = 32 * 1024 * 1024

type formBinding struct{}
type formPostBinding struct{}
type formMultipartBinding struct{}

func (formBinding) Name() string {
	return "form"
}

func (formBinding) Bind(req *http.Request, obj interface{}) error {
	if err := req.ParseForm(); err != nil {
		return err
	}
	if err := req.ParseMultipartForm(defaultMemory); err != nil {
		if err != http.ErrNotMultipart {
			return err
		}
	}
	if err := mapForm(obj, req.Form); err != nil {
		return err
	}
	return common.Validate(obj)
}

func (formPostBinding) Name() string {
	return "form-urlencoded"
}

func (formPostBinding) Bind(req *http.Request, obj interface{}) error {
	if err := req.ParseForm(); err != nil {
		return err
	}
	if err := mapForm(obj, req.PostForm); err != nil {
		return err
	}
	return common.Validate(obj)
}

func (formMultipartBinding) Name() string {
	return "multipart/form-data"
}

func (formMultipartBinding) Bind(req *http.Request, obj interface{}) error {
	if err := req.ParseMultipartForm(defaultMemory); err != nil {
		return err
	}
	if err := mappingByPtr(obj, (*multipartRequest)(req), "form"); err != nil {
		return err
	}

	return common.Validate(obj)
}

type multipartRequest http.Request

var _ setter = (*multipartRequest)(nil)

var (
	multipartFileHeaderStructType = reflect.TypeOf(multipart.FileHeader{})
)

// TrySet tries to set a value by the multipart request with the binding a form file
func (r *multipartRequest) TrySet(value reflect.Value, field reflect.StructField, key string, opt setOptions) (isSetted bool, err error) {
	if value.Type() == multipartFileHeaderStructType {
		_, file, err := (*http.Request)(r).FormFile(key)
		if err != nil {
			return false, err
		}
		if file != nil {
			value.Set(reflect.ValueOf(*file))
			return true, nil
		}
	}

	return setByForm(value, field, r.MultipartForm.Value, key, opt)
}